A guide to the trees of Menlo College - Stanford …yy216fw0579/...The higher vascular plants may be divided into two more ar-bitrary groups: herbaceous, or soft-stemmed plants, and

a guide to the

TREES OF MENLO COLLEGE

By

STUART A. OLSON

MENLO COLLEGE

menlo park, California

Contents

Introduction 1

Trees 2

Using a Key 3

Key to the Genera 5

Trees of Menlo College 13

Class Gymnospermae 14

Class Angiospermae 20

Glossary 37

Useful references 41

INTRODUCTION

This book is written with the intention of teaching thebotany student the methods and procedures involved in iden-tifying plants, and to familiarize the student with the speciesof trees found on the campus of Menlo School and College.

Over 70 species of trees are represented on the Menlocampus. Of these, most are identified in this manual. Identi-fication of trees in this book is based primarily upon leafstructure and arrangement. Some species are difficult to iden-tify precisely without studying floral structure, or becausetheir growth form may be atypical because of such factors aspruning, local environmental conditions, or because of the exis-tence of a great variety of horticultural forms. In theseinstances the trees are identified to the genus and are treatedcollectively (willows, cherry, plum, for example).

Only fifteen species of the trees found on the Menlo cam-pus are native to the San Francisco Bay Area. The rest areintroduced and represent types from many parts of the UnitedStates and the world. This gives the student an opportunity tobecome familiar with a wide variety of families of trees.

TREES

Plants are generally classified into two major groups: theThallophyta, simple bodied plants with unicellular reproductivestructures, and the Embryophyta, those plants which have morecomplex bodies, multicellular reproductive organs and produce anembryo in their life cycle. This latter group may be arbitrarilydivided into non-vascular and vascular plants. The vascularplants are those which contain specialized structures, vessels,for conducting food and water throughout the plant body.

The higher vascular plants may be divided into two more ar-bitrary groups: herbaceous, or soft-stemmed plants, and woodyplants. VJoody plants are those which have vessels in which thecell walls have, in addition to cellulose, a chemical calledlignin which makes them quite hard and rigid. Woody plants arefound in the classes of seed plants known as Gymnospermae, whichare all woody, and the Angiospermae or flowering plants which in-clude some woody and herbaceous plants. The woody plants aregenerally described as being either trees or shrubs. Althoughthere is some overlap, a tree is usually considered to be a woodyplant with a single main stem which is over fifteen feet tall atmaturity. A shrub is usually a multiple stemmed woody plant which,at maturity, is less than fifteen feet tall. There is sometimesdifficulty in determining whether a specimen is a small tree or alarge shrub, and often the terms "tree-like" or "shrub-like" areused because of this.

The plants described in this manual are, with few exceptions,limited to those which normally exist as trees by the abovedefinition.

USING A KEY

There are several ways to learn the identity of a plant:1) Ask someone who knows it: 2) Look at a collection of pic-tures; 3) Compare it to herbarium specimens if they are avail-able; 4) Use a key. Use of the keys in this book requires arudimentary knowledge of some descriptive biological terms.These terms are included in the glossary at the end of the book.

A key is a device used by the student of plant or animaltaxonomy to identify groups or kinds of organisms. Many typesof keys are used, and these are normally constructed so thatorganisms are arranged into groups with similar characteristics,and then broken down into smaller groups which have more speci-fic characteristics that distinguish the groups from one another.Eventually individual types are selected by traits which dis-tinguish them from other kinds.

Most keys offer the user alternatives of choices. Keys areusually dichotomous, that is, the choices are paired. Eachchoice leads either to another pair of alternatives or to afinal identification.

The keys in this book are strictly dichotomous. Each pairof choices is numbered. Each choice is, essentially, a descrip-tion of a characteristic or group of characteristics with whichthe specimen to be identified should be compared.

If the specimen fits the description for choice number onein a key, the student should then go on to the next descriptionwhich immediately follows the first. If the specimen does notfit, then the student should go on to the second choice numberone. It is always wise to read both members of a pair of descrip-tions and select the most accurate. "Keying" is more an art thana science. As one progresses through the keys in this manual, heis led from one set of alternatives to another, and ultimately tothe genus of the plant in question, with a page reference. Inturning to that page he will find a description of the speciesof trees in that genus that are found on the campus of Menlo Col-lege and the identification is complete.

KEY TO THE GENERA

1. Leaves parallel veined and arising from the summit ofthe main trunk or its branches (MONOCOTS) Page 7

1. Leaves net-veined or not distinctly parallel veined,arising from branches or branchlets.

2. Leaves compound Page 8

2. Leaves simple

3. Leaves less than 3/8 inch wide, ovate, linear,needle-like, awl-shaped or scale-like

4. Leaves not scale-like Page 6

4. Leaves scale-like, surroundingbranchlets Page 7

3. Leaves more than 3/8 inch wide

5. Leaves opposite Page 8

5. Leaves alternate Page 9

LEAVES NOT SCALE-LIKE

1. Leaves needle-like, in clusters on branches

2. Leaves usually more than 2 inches long, inbundles of 2 to five Pinus Page 17

2. Leaves usually less than 2 inches long, inclusters of more than 5 needles (some singleneedles on young shoots Cedrus Page 16

1. Leaves all single (never in clusters) on branches

3. Leaves linear, 1/4 to 3/8 inch wide, over 1-1/2inches long, fruit a legume Acacia Page 32

3. Leaves less than 1/4 inch wide

4. Leaves awl-shaped

5. Free part of leaf less than 1/4 inch long,bases adherent to stem (decurrent)

Sequoiadendron Page 15

5. Leaves spreading from stem, spirally arrangedand overlapping giving smaller branchlets arope-like appearance Araucaria Page 14

4. Leaves linear or narrowly lanceolate

6. Leaves, when removed, leaving round scars onbranches; cones with 3 pointed bracts pro-truding from cone scales Pseudotsuga Page 17

6. Leaves not leaving round scars when removed

7. Leaves stiff, sharp and 4-angled, leavingshort distinct pegs on branches whenfalling Picea Page 16

7. Leaves more flexible, often pointed butnot stiff and prickly to the touch

8. Leaves attached to branches by decurrent bases

9. Leaves with short petioles, continuouswith bases, falling singly .... Taxus Page 14

9. Leaves sessile, persistent, fallingwith branchlets Sequoia Page 15

8. Leaves with distinct petioles attached bystalk-like processes to sten

Pseudotsuga Page 17

LEAVES SCALE-LIKE, SURROUNDING BRANCHLETS

1. Branchlets forming decidedly flat sprays

2. Leaves apparently 4 at a node, internodes longerthan broad Libocedrus Page 18

2. Leaves 2 at a node, internodes about as long as broad

3. Cones oblong with overlapping scales; branchletsover 1/12 inch thick Thuja Page 18

3. Cones globular, peltate; branchlets less than1/12 inch thick Cupressus Page 18

1. Branchlets not forming flat sprays

4. Leaves more awl-shaped than scale-like, spirallyarranged, 1/4 to 1/2 inch long Sequoiadendron Page 15

4. Leaves definitely scale-like, 2 at a node...Cupressus Page 18

MONOCOT TREES

1. Leaves not divided

2. Leaves 1-1/2 to 3 feet long, 1 to 2-1/2 inches wide,drooping against trunk and turning brown with age..

Cordyline Page 20

2. Leaves 1 to 2 feet long, 1 to 1-3/4 inches wide,fairly rigid, sword-shaped, leather Dracaena Page 20

1. Leaves divided (Palms)

3. Leaves fan-shaped (palmate)

4. Tall smooth stemmed trees, old leaves hangingagainst stems Washingtonia Pj-ge 21

4. Shorter plants, stems hairy and covered withold leaf bases

5. With a single main trunk; petioles armed withlong sharp spines Chamaerops Page 20

XfI ^5. With several stems branching very near baser, petioles yoften with small teeth but not spines ... \fr

Trachyci^rpus Page 21

3. Leaves pinnate (Feather palms)

6. Trunk covered with old leaf bases Phoenix Page 21

6. Trunk smooth Jubaea Page 21

LEAVES COMPOUND

1. Leaves twice-pinnately compound, less than 4 inches wide,prominent glands on upper side of rachis Acacia Page-32

1. Leaves once pinnately compound

2. Larger leaflets usually over 2 inches long

3. Leaflets entire

4. Leaflets alternate, petiolulate.... Cladrastis Page 33

4. Leaflets sessile, opposite Juglans Page 23

3. Leaflets toothed or lobed

5. Leaflets less than 1/2 inch wide; fruit adrupe, in clusters Schinus Page 34

5. Leaflets over 1/2 inch wide; fruit a nut ...Juglans Page 23

2. Larger leaflets usually less than 2 inches long

6. Leaflets entire, over 1/2 inch wide; plantusually thorny Robinia Page 33

6. Leaflets toothed, less than 1/2 inch wide...Schinus Page 34

LEAVES OPPOSITE

1. Leaves palmately lobed and veined Acer Page 34

1. Leaves not lobed, entire

2. Leaves less than 3 times longer than broad, lateralveins curving upward toward apex Cornus Page 35

2. Leaves 3 or more times longer than broad

3. Leaves 1 to 3 inches long, 3/8 to 5/8 incheswide; fruit a drupe 1/2 to 1 inch long Qlea Page 36

3. Leaves 3 to 8 inches long

4. Leaves long and tapering (lanceolate), 1 inch orless wide, often in whorls of three.... Nerium Page 36

4. Leaves ovate- lanceolate, more than 1 inchwide •• Ligustrum Page 35

9

LEAVES ALTERNATE

1. Leaf margins entire (or wi±h very few coarse teeth)

2. Leaf blade 3 or more times longer than broad

3. Foliage when crushed giving off odor of bay rum ...Umbellularia Page 29

3. Foliage without odor of bay rum

4. Leaf blade 2 inches or more wide, thick andleathery Magnolia Page 28

4. Leaf blades less than 2 inches wide

5. Leaves with 2 or more main veins from base or, if one,then a distinct gland on margin near base.... Acacia Page 32

5. Leaves with a single distinct midrib

6. Leaves sometimes over 4 inches long with leafy stipuleat base of petiole Salix Page 22

6. Leaves less than 4 inches long, without stipules

7. Fruit a capsule; seeds in a sticky substance ...Pittosporum Page 3 0

7. Fruit a small berry Laurus Page 20

2. Leaf blade usually less than 3 times longer than broad

8. Leaves distinctly pubescent, rusty or scurfy beneath

9. Leaves more than 1-1/2 inches wide Magnolia Page 28

9. Leaves less than 1-1/2 inches wide; fruit a leatherycapsule; seeds in a sticky substance .... Pittosporum Page 30

8. Leaves glabrous on both sides**Leaves round, cordate at base;fruit a legume..Cercis Page 33**Leaves emitting odor of camphor when crushed...

Cinnamomum Page 2 9

10. Leaves usually less than 1-1/2 inches long

11. Leaves varying from entire to toothed on sameplant; fruit an acorn Quercus Page 24

11. Leaves entire;fruit a leathery capsule..Pittosporum Page 30

10. Leaves all more than 1-1/2 inches long

12. Leaves glaucous or pale beneath,.thin but firm;fruit a large, juicy berry Diospyros Page 35

12. Leaves not glaucous or pale beneath

13. Petioles usually more than 3/4 inches long

10

14. Leaf blades usually less than 3 inches long,occasionally with a few lobes or blunt teeth...

Sterculia Page 35

14. Leaf blades much more than 3 inches long Persea Page 29

13. Petioles usually less than 3/4 inch long

15. Petioles often winged or jointed near summit; fruit1-1/2 inches long or longer, leathery Citrus Page 34

15. Petioles not winged or jointed

16. Fruit a drupe; some toothed leaves on plant...Prunus Page 31

16. Fruit not a drupe; leaves all entire

17. Fruit a 3-valved capsule; seeds in a stickysubstance Pittosporum Page 3 0

17. Fruit a berry, 1/4 to 1/2 inch long; leaves 2 to4-1/2 inches long Laurus Page 20

1. Leaf margins toothed or lobed

18. Leaf margins distinctly lobed

19. Leaves notched or truncate at apex

20. Leaves notched forming 2 lobes, fan shaped withdichotomous venation Ginkgo Page 14

20. Leaves truncate at apex Liriodendron Page 28

19. Leaves not notched or truncate at apex

21. Leaves palmately veined and lobed

22. Leaves rough to the touch, 3 to 5 lobed, 8 to12 inches long Ficus Page 28

22. Leaves not rough to the touch, shorter

23. Leaf lobes entire, pointed at apex (most of the leaveson the tree are entire, not lobed) Sterculia Page 35

23. Leaf lobes irregularly toothed, leaves "star-shaped" Liquidambar Page 31

21. Leaves pinnately veined and lobed

24. Plants thorney; fruit a red berry-like structure........... Crataegus Page 31

24. Plants not thorny; fruit an acorn Quercus Page 24

18. Leaves variously toothed; definitely not lobed

25. Leaves evergreen

11

26. Fruit an acorn Quercus Page 24

26. Fruit not an acorn

27. Leaves undulate, spiny toothed, leathery, glossy...Ilex Page 34

27. Leaves not undulate or spiny

28. Leaves slightly unequal at base Ulmus Page 27

28. Leaves equal at base

29. Leaves finely serrate; fruit a waxy, berry-likenutlet Myrica Page 22

29. Some leaves entire; fruit a drupe Prunus Page 31

25. Leaves deciduous

30. Plants dioecious; fruit a capsule; seeds with tuftsof hairs

31. Leaves at least 2 times longer than wide,stipulate Salix Page 22

31. Leaves less than 2 times longer than wide,roughly triangular in shape Populus Page 22

30. Plants with perfect or monoecious flowers

32. Fruit an acorn Quercus Page 24

32. Fruit not an acorn

33. Leaves unequal at base Ulmus Page 27

33. Leaves equal at base

34. Lateral veins straight and paralle; fruit composedof nutlets in woody cone-like catkins Betula Page 23

34. Lateral veins not straight and parallel

35. Fruit a drupe Prunus Page 31

35. Fruit a pome Malus Page 32

13

TREES OF MENLO COLLEGE

On the following pages, the major tree species found on thecampus of Menlo College are described. The descriptions are in-tended to aid the student in his identification of the plantsand to provide the reader with some facts relating to the naturaldistribution of these trees and some of the uses which man hasmade of them.

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CLASS GYMNOSPERMAE

Ginkgoaceae - Gingko Family

Ginkgo biloba - Maidenhair Tree

ItThis tree is native to China,is a broad-leaved deciduous gymno-sperm with sparse, graceful ascendingbranches. It is widely cultivated andthe only living member of its family.This species is dioecious and thefleshy seed (often mistakenly calleda fruit) produced by the female givesoff an extremely disagreeable odorwhen ripe. This tree is relativelyfree of insect pests which makes itquite desirable as a landscape speci-men.

Taxaceae - Yew Family

Taxus baccata - English Yew

A densely branched tree, nativeto Europe, Asia and northern Africawhich may be shaped by pruning andused for ornamental purposes. Thereare a number of cultivated varieties.

Araucariaceae - Araucaria Family

Aracauria excelsa - Norfolk IslandPine

This tree is a member of thesame genus as the Monkey-Puzzle treeand the Bunya-Bunya tree which arenative to Chile. It is native toNorfolk Island and is the mostwidely cultivated species of Arau -caria in California. AlthougFTtmay reach 70 or more feet in height,it is a very popular potted plantand is used in bonsai gardening. Inspite of the common name, it is nota pine.

15

Taxodiaceae - Redwood Family

Sequoia sempervirens - CoastRedwood

The genus Sequoia is namedafter a Cherokee Indian chief,Sequoyah. The specific name -sempervirens - means "alwaysnpervi]

ring".living". The Coast Redwood isone of the longest-lived treesin the world, many specimens over3,000 years in age.

It is also the tallest oftrees, its closest competitorsbeing the Giant Sequoia, Douglasfir, and some Eucalyptus treesfrom Australia.

The species ranges from theBig Sur area of California tosouthern Oregon along the coast,the finest specimens being foundin northern California. It isextremely dependent upon fog andrarely germinates from seed.

Sequoiadendron gigantea - GiantSequoia, or Big Tree

The most massive of allliving things. This species isfound naturally only in 32 iso-lated groves on the west slopesof the Sierra Nevada in Califor-nia. It is dependent upon firefor its survival, as this isnecessary for thinning out theforest shrubs which compete withits seedlings. Unlike the coastredwood, its wood makes verypoor quality lumber.

16

Pinaceae - Pine Family

Cedrus - Key to the species.

Pendulus branchlets; leaves up to twoinches long C. deodara

Branchlets rarely pendulous; leaves usuallyless than 1-1/4 inches long C. atlantica

Many trees are commonly called "cedar". None of these is nativeto North America. Only members of the genus Cedrus are truecedars, and two of the three species are planted on the Menlocampus.

Cedrus deodara. Deodar Cedar

Native to the Himalayas. Fre-quently planted throughout Californiaas an ornamental tree in areas wherethere is not prolonged freezing. Abeautiful tree, with graceful hangingbranches.

Cedrus atlantica. Atlas Cedar

A large tree, with large up-right cones. Native to the AtlasMountains of Northern Africa, it iswidely planted throughout the PacificCoast from British Columbia to SanDiego.

Picea pungens - Colorado Blue Spruce

A tall tree, often 100 feethigh, and native to the Rocky Moun-tains. It is pyramidal in generalshape with blue-green foliage. TheColorado State Tree.

17

Pinus

Several species are found on campus and are difficult todistinguish without cones present. Only one species is describedhere, as there are several specimens on the campus which occurnaturally.

Pinus radiata - Monterey Pine

Native to central coastal Cali-fornia. This tree often grows toover 100 feet in height, and may berecognized by its dark green foliage,irregular rounded crown and stoutoblique cones which persist on thestems for up to 12 years. There are3 leaves (rarely 2) to a bundle.This tree is often planted for land-scape purposes and (questionably insome cases) for reforestation.

Other species of pine on the campus are P. canariensis -Canary Island Pine and P_. halepensis - Aleppo~Pine.

Pseudotsuga menziesii - Douglas Fir

Douglas Fir is the most impor-tant lumber tree in North America.It is found throughout the west,especially in the mountains from theRockies to the Pacific Coast. Itachieves its best growth in thePacific Northwest and is secondonly to the Coast Redwood in height.It is the primary source of materialfor rough housing construction, ply-wood, etc. It is not a fir (thetrue firs belong to the genus Abies)but closely resembles the Hemlock.The name Pseudotsuga means "falsehemlock".It is easily recognizedby its cones, the bracts lookinglike the hind legs and tail of micegoing into their holes.

18

Cupressaceae - Cypress Family

Cupressus - Cypress

There are several species ofcypress on the campus. These are,however, difficult to distinguishbecause of the effects of pruning,and, because mature cones aren'treadily available to the student,they will be treated collectivelyhere.

Two species of cypress occuras native to the Santa Cruz Mts.:Monterey Cypress, which is widelyplanted as a windbreak and existsnaturally in a grove at PointLobos on the Monterey Peninsula,and Santa Cruz Cypress, which isfound only in a few isolatedareas between Santa Cruz and SanFrancisco.

Libocedrus decurrens - Incense-Cedar

Not a true cedar, this treebears a superficial resemblanceto the Giant Sequoia and is oftenmistaken for it in the SierraNevada where it is native. It isalso found throughout the highercoast ranges from Oregon to Baja,California. It is quite aromaticand a handsome tree. It is easilyidentified by its unusual coneswhich split open along a centralplane.

19

Two species are found on campus:Thuja occidentalis - American Arbor-Thujavitae (tree of life), which is asmall tree, often shrub-like, andnative to northeastern United Statesand southeastern Canada, and Thujaplicata - Western Red-cedar, aforest tree of the Pacific statesoften attaining a height of 200feet. It is found from Alaska toHumboldt County, California and isplanted for its stately beauty.The early Indians carved canoes fromthe trunks of these trees and alsoused them for construction of houses.The wood is easily carved and was amajor source of material for totempoles. In modern use, its greatestimportance to the lumber and buil-ding industries is that it is thesource of 80 percent of the shinglesand clapboards used in home construc-tion.

20

CLASS ANGIOSPERMAE

Subclass Monocotyledonae

The most advanced members of the plant kingdom are the mono-cotyledonous angiosperms. They are, however, traditionallylisted before the dicots in most floras. Most of the monocotsare herbaceous plants with only a very few tree species.

Liliaceae - Lily Family

Cordyline australis - Green Dracena

Native to New Zealand

Dracaena draco - Dragon Tree

Both of the above species arewidely planted in California asornamentals. They are palm-likebut can be distinguished from palmsby their simple leaves. The nameDracaena is after the female dra-gon^Tn~e dried juice from theseplants supposedly resembles dra-gon's blood. The North Americancounterpart of these trees is theJoshua Tree"of the southwesterndeserts (Yucca brevifolia).

Palmaceae - Palm Family

Chamaerops humilis - Hair Palm

Chamaerops comes from theGreek for"dwarf bush". Thisspecies is very hardy and is theonly palm native to Europe whereit is found in the Mediterraneanregion.

Trachycarpus excelsa - WindmillPalm

This plant is native to cen-tral and eastern China. It is aslender pain rarely over 30 feethinh and one of the hardiest culti-vate.1 in California.

21

Washingtonia -

There are 2 species of thisgenus which is named after GeorgeWashington: W. filifera, Cali-fornia Washington Palm, which isnative to the deserts of south-ern California and is heavierand stouter than its close rela-tive, W. gracilisf MexicanWashington Palm, which is nativeto Baja, California. This spe-cies is distinguished from W.filifera by its more slendeFtrunk,shorter petioles and moreextensively divided leaves.

Phoenix canariensis - CanaryIsland Date Palm

This tree is extensivelyplanted in California and is veryhardy. The foliage is very denseand spreading. The fruit of thisspecies, by the way, is not edi-ble.

Jubaea spectabilis - Syrup Palm,Monkey-Coconut

Native to Chile. One of themost beautiful of the palms, witha smooth, massive trunk up to 30feet high and 3 to 5 feet in dia-meter. The fruits are small andresemble small coconuts, hencethe name Monkey-Coconut. TheChilean natives prepare a mixturecalled "palm-honey" from the sapof the stem.

22

SUBCLASS DICOTYLEDONAE

This is the largest major group of plants, with approximately200,000 species. Most of these are herbaceous, as are 99 percentof the monocots. Except for the gymnosperms, which are all woodyand a few monocots (palms, etc.), the vast majority of treesbelong to this group of flowering plants.

Salicaceae - Willow Family

Populus balsamifera - Cottonwood

Native from northeastern NorthAmerica to the Rockies, and occa-sionally planted in California as astreet or park tree, this speciesis a source of pulp for the paperindustry. The wood is rather softand of poor quality for construc-tion. It is used, however, as afiller material covered by veneersfor inexpensive furniture.

Salix sp. - Willow

The genus Salix is a difficultone in terms of identifying thespecies (with a few exceptions) be-cause of the necessity to haveflowers present for correct iden-tification, and because of thevariety of growth patterns thatmay exist within a single species.Many of the specimens on the campushave been rather severely and ex-tensively pruned so that theirgrowth habit is atypical. Thewillows as a group are very inter-esting in terms of the uses towhich they have been put. Becauseof their very rapid growth, theyare often planted to prevent ero-sion along streams and highways.

Myricaceae - Myrtle or Sweet-Gale Family

Myrica californica - CaliforniaWax-Myrtle

An evergreen, small tree or,in its natural state, a largeshrub. Found in the coast rangesfrom Washington to Santa Monica.

23

Juglandaceae - Walnut Family

juglans regia - English Walnut

juglans is a contraction of"Jove's glands", a fairly accurateif not puritanical description ofthe husked fruit. "Jove's glands"is actually a corruption of theLatin Jovis, Jupiter, and glans,nut. This tree is the source ofthe commercial walnut and inorchards is usually grafted tothe stem of Juglans hindsi, theCalifornia Black Walnut, which hasa root system that is better adap-ted to native soils.

Betulaceae - Birch Family

2 species on campus:

Betula alba - White Birch

Native to Europe. The barkis white, the leaves resemblethose of B. papyrifera and thefruiting catkins are about 1 inchlong. There is a great variety ofhorticultural forms planted in Cali-fornia, the most common being B_.alba pendula or Weeping White Birch,with long drooping branches.

Betula papyrifera - Paper Birch -Canoe Birch

Adult trees easily recognizedby the white, peeling bark. Thefruiting catkins are 1-1/2 to 2inches long. Native to Canada andeastern United States, this is thetree which the Indians used forbuilding canoes (the bark was usedto cover a frame built of flexiblewood strips from several species oftrees or shrubs) and for primitivepaper. The bark of this tree, be-cause of its high resin content, isan ideal source of kindling for firesbuilt in snow when firewood suppliesin the forest are wet. It burnsvery readily and at a very hightemperature.

24

Fagaceae - Beech Family

The only representatives of the beech family on the campusare the oaks. In fact, there are no beeches native to California.

The western oaks are not the tall stately trees as are theoaks of northeastern United States and Europe, but many of themare quite massive. As a rule, they have been spared the woods-man's axe because of the very hard, twisted wood which makes themunsuitable for lumber (though, unfortunately, excellent for fire-wood) . The aesthetic quality of the oak adds great beauty to theCalifornia landscape.

Quercus - Oaks (from Celtic for "fine tree")

Key to species

1. Leaves not lobed, evergreen

2. Leaves green, glabrous on both surfaces withtufts of axillary hairs beneath, leaf marginstoothed Q. agrifolia

2. Leaves dull beneath; bark very thick, soft,deeply furrowed Q. suber

1. Leaves lobed, deciduous

3. Leaf lobes rounded... Q. lobata

3. Leaf lobes not rounded, lobesspine-tipped.

4. Leaves glabrous beneath, withsmall tufts of axillary hair Q. coccinea

4. Leaves pubescent beneath* noaxillary hairs Q. kelloggi

25

Quercus agrifolia - Coast Live Oak

The specific name agrifoliais believed to be the result of aprinter's error which has been per-petuated since the tree was firstdescribed. The original word wasprobably aquifolia - meaning "holly-leaved" as the leaves resemble thoseof the holly tree. This species isthe "Menlo Oak" which is displayedon the school seal. The tree isevergreen, as are many of the Cali-fornia oaks, and is abundant through-out the coastal valleys and foot-hills of California. This oak isprobably the world's most photo-graphed tree, as groves of it formthe backdrop for great numbers ofmotion pictures depicting every-thing from "Robin Hood" to cowboysand indians, or anything else Holly-wood needs a handy forest for.

Quercus suber - Cork Oak

The source of commercial cork.The bark of this European and NorthAfrican native is cut into corksfor a great variety of uses. Manyof these are planted as ornamentalsaround California. In a conversa-tion with Mr. Leon Loofbourow, hementioned that in the early 1940's,the government surveyed the loca-tion of all Cork Oaks in the localarea for possible use as a corksupply for life preserver's to beused during World War II should theneed have arisen.

26

Quercus lobata - Valley Oak, Roble

Found throughout Californiafrom the foothills of the SierraNevada to the coast. From a dis-tance, the characteristic thickcheckered gray bark distinguishesthis large graceful tree. It isdeciduous, and in the winter themistletoe, which parasitizes theoak, becomes conspicuous.

The acorns of this oak, aswell as others, were a staple foodof the California Indians. Thenuts were ground, leached of thetannins present in them, and usedas a source of flour for baking,or served as a mush. Because theValley Oak grows in the valleyswhere the soil tends to be richest,it has often been sacrificed tomake room for agriculture.

Quercus kelloggi, Black Oak, and

Quercus coccinea, Scarlet Oak arevery difficult to distinguish whenimmature, and the few specimens oncampus are relatively young. Theoaks generally are divided into 2major groups - the black oaks ("live"oaks, Scarlet Oak and Black Oakbelong to this group), have lobed orunlobed leaves which are spine-tipped, whereas the White Oak leaves,if lobed, do not have spines on theleaf edges.

27

Ulmaceae - Elm Family

Ulmus. Elms can be identified by their straight-veinedleaves which are sharply serrate and oblique at the base. Elmsare not native west of the Rocky Mountains. Several species arefound on campus. Although elms are naturally deciduous, thereare some horicultural varieties that are evergreen.

Key to species

1. Leaves evergreen several varieties of ornamentalelms planted as part of campus landscaping.

1. Leaves deciduous, rather rough to touch.

2. Branchlets corky-winged U_. campestris

3. Branchlets not corky-winged U. americana

Ulmus campestris - English Elm

Native to England and Europeoften planted as a park and shadetree.

Ulmus americana - White Elm,American Elm

Native to eastern UnitedStates.

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Moraceae - Mulberry Family

Ficus carica - Fig

Native to the area around theMediterranean. Many varieties ofhorticultural forms have been devel-oped for their edible fruits. Theleaves of this tree are very large,palmately veined and lobed. Theleaves are gently toothed or wavyalong the margins and slightlyrough in texture.

Magnoliaceae - Magnolia Family

This family is very closely related to the buttercup family,which is considered by most taxonomists to be the most primitiveof the living families of flowering plants. The buttercup familyis probably ancestral to the monocots and to the rest of the dicots,but is placed here because, traditionally, the petal-less floweringplants have been listed first in taxonomic lists or floras.

Liriodendron tulipifera - TulipTree

So called because of the resem-blance of the leaves in silhouetteto the flower of the tulip. Thetree is native in the forests fromsouthern New England to Florida.

Magnolia sp. - Magnolia

There are several species ofmagnolia on campus, but these willbe treated here collectively. As agroup they have fairly large, thickleathery leaves and huge, showyflowers with 3 petal-like sepalsand 6 to 15 petals and numerouspistils and stamens. The fruitis a large, usually upright, cone-like structure. The various spe-cies are native to eastern andsouthern United States, CentralAmerica and eastern Asia. Theyare frequently planted in Califor-nia for their showy flowers whichbloom throughout the summer.

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Lauraceae - Laurel Family

Cinnamomum camphorurn - CamphorTree

A small tree with thin,light green, glossy evergreenleaves. The leaves, when crushed,have the odor of camphor. Many ofthe members of the laurel familyare extremely aromatic and thesource of spices and food season-ings. Native to China and Japan.

Laurus nobilis - Sweet Bay

A small evergreen tree or,as a result of pruning, shrubwith small purple berries forfruits. Native to southernEurope and southwestern Asia.

Persea americana- Avocado

This tree is native to tro-pical regions of the westernhemisphere. It is greatly branched,up to 60 feet high, with large ob-long leaves (to 10 inches inlength). It is extensively plantedin southern California for itslarge fleshy fruits. Menlo canthank Mr. Russell, College Direc-tor, and his wife for its finespecimen which they grew fromseed in a jelly jar a number ofyears ago.

Umbellularice californica - Cali-fornia Laurel

Oregonians call this tree "Ore-gon Myrtle". Obviously the resultof local pride, as it is the sourceof myrtlewood which is used for allkinds of things from knick-knacksto cabinetry, but it really belongsto California. In California it isknown as Laurel, California Bay, orBay Laurel. It is closely related

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to the European Bay trees, the leavesof which are used as a spice andseasoning. The spicy odor of theleaves of this tree is very much evi-dent to one standing near it in thewoods. In this area it is a large,graceful evergreen tree, while inOregon it tends to be rather stunted.It is native from southwestern Ore-gon through the Coast Range tosouthern California and in the foot-hills of the Sierra Nevada to 3000feet.

Pittosporaceae - Pittosporum Family

Two species on campus:

P_. undulatum and P_. tenuifolium.

The genus name comes from theGreek pitte (tar or pitch) and sppros(seed), describing the seeds whichare embedded in a sticky substance ina capsule fruit.

P. tenuifolium is usually alarge shrub with dark green leaves,and P_. undulatum is a small tree withyellow-green leaves with undulate(wavy) margins. Native to Australiaand New Zealand.

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Hamamelidaceae - Witch-Hazel Family

Liguidambar styraciflua - SweetiquGu:

This species is native to theeastern half of the United States,and into Mexico where it is neverabundant but scattered throughoutthe forests. Its wood is used ex-tensively for furniture but it isnot an important lumber tree. Thealternate, star-shaped palmatelylobed leaves with serrate edgeshelp to identify this species.

Rosaceae - Rose Family

This family is often treated by some taxonomists as severalseparate families - the Rosaceae or Rose family, the Amygdala-ceae or Peach family, and the Malaceae or Apple family. Herethey are treated as one group.

Crataegus oxycantha - EnglishHawthorn

Native to Europe and NorthAfrica, there are many varietiesof hawthorn grown as ornamentalsin the United States. One of thespecimens on the Menlo campus isalmost thornless, although the spe-cies normally has numerous stoutthorns about 1 inch long. Theleaves turn bright red in the fall.The tree is quite small, rarelyover 15 feet high.

Prunus

To this genus belong the plums, peaches, cherries, etc.Because of the great variety of horticultural species and varie-ties developed for agriculture and landscaping, only one speciesis described below, although several are found on campus. Thegenus represents a major fruit industry in California, especial-ly in the Santa Clara valley which is world famous for itsprunes.

Prunus cerasifera - Purpleleaf Plum

A horticultural varietyplanted as a lawn and street treefor its colorful reddish-purpleleaves.

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Malus

This is the apple genus. Animportant food source. Again, theindividual species will not bedescribed because of the variety ofhorticultural forms which areplanted both commercially and forlandscaping. The trees are usuallyrather gnarled and twisted in theirgrowth patterns and make interes-ting garden specimens.

Fabaceae - Pea Family

This is a very large family, most of its members being herba-ceous plants such as peas, sweet pea, clover, alfalfa, lupines loco-weed, etc. There are also many species of trees and shrubs in thisfamily. The fruit is a legume and the fruits of such plants as beans,peas, peanuts and others are grown commercially as a major world foodsource.

Acacia - Key to the Species

1. Plants with compound leaves A. decurrens

1. Plants with what appear to be simple leaves.

2. Leaves over 1/2 inch wide, dark green;large tree A. melanoxylon

2. Leaves less than 1/2 inch wide, palegreen; small tree or large shrub A. longiflora

Acacia melanoxylon - BlackwoodAcacia

A handsome tree with dark greenleaves and dark grey furrowed bark.Native to Australia and plantedthroughout coastal California as ashade tree.

Acacia longiflora - Sydney GoldenWaTEle

Native to Australia, very"willow-like" in its overall appear-ance, and planted as an ornamentaltree in California.

The leaves of the above Acaciasare not leaves in the true sense,but phyllodia; the expanded,flattened leaf rachises.

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Acacia decurrens var. dealbata -Silver Wattle

Native to Australia. Atmaturity, this is a large tree (upto 60 feet high) with very smallleaflets which are grey green andgive the leaves a feathery appear-ance. This tree is widely plantedfor its aesthetic value.

Cercis canadensis - American Redbud

Native to eastern UnitedStates and occasionally planted inCalifornia. A common understorytree in the eastern forests, it hasno great commercial value althoughit is sometimes used for furnitureand cabinet making.

Cladrastis lutea - Yellow-Wood

Native to southeastern UnitedStates. This tree is occasionallycultivated for its foliage andclusters of white flowers whichappear in the spring. It is rela-tively rare in the wild statewhere it is of minor importance asan understory species.

Robina pseudoacac ia - Black Locust

A tree of the eastern UnitedStates which is frequently plantedas a shade tree. It withstandsdrought and poor soils quite well.The wood is very hard and durablewhich makes it a good material forfine furniture. The extensivefibrous root system of this treemakes it extremely useful whenplanted in erosion control pro-grams.

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Rutaceae - Rue Family

Citrus - There is a tremendous variety of cultivated forms of sixspecies of this genus grown throughout central and southern Cali-fornia. These will not be separated here although the campus hasseveral varieties. Included on campus are varieties of orange,lemon and lime. The most important economic value of these plantsis, of course, as a food source rich in vitamin C.

Anacardiaceae -'Sumac Family

Schinus molle - California PepperTree

Native to Peru. This speciesis dioeceous. If you are adven-turous you might collect the littlered "peppercorns" or fruits of thefemale of this species, dry themand grind them in your pepper mill.It makes an interesting seasoning.The tree is planted in the UnitedStates for its picturesque "weepingwillow" appearance.

Aquifoliaceae - Holly Family

Ilex aguifolium - English Holly

Native to Europe and Asia.Used in this country primarily asan ornamental because of its darkgreen, glossy foliage and redberries which persist through thewinter. There are several speciesof holly native to eastern UnitedStates but which are rarely culti-vated in the west. This speciesis often used in making Christmaswreaths.

Aceraceae - Maple Family

Acer palmatum - Japanese Maple

There are two species of maplenative to the San Francisco penin-sula. Neither is found on campus.Ours was "made in Japan" or at leastits ancestors were. This species isused strictly as an ornamental.Native to Japan and Korea.

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Sterculiaceae - Sterculia Family

Sterculia

There are 2 species of thisgenus on campus: S_. diversifolia,Black Kurrajong, and S. acerifolia,Flame Tree or Bottle Tree"! The 2species are difficult to disting-uish. S. diversifolia has leaves2 to 3 inches long, while S. acer-ifolia has leaves which are" usuallyover 4 inches long (see sketches).Both are native to Australia andare handsome trees.

Cornaceae - Dogwood Family

Cornus capitata - Evergreen Dogwood

A small tree, often shrub-like. Native to the Himalayas.

Ebenaceae - Ebony Family

Diospyros virginiana - Persimmon

A medium size tree nativeto eastern United States. Severalagricultural varieties have beendeveloped for their fruit which israther fleshy.

Oleaceae - Olive Family

Ligustrum lucidum - Glossy Privet

This species is native toChina and Japan and is plantedthroughout the U.S. In this areait grows as a small tree and isused in landscaping quite exten-sively. In more severe climates,provided the winters aren't tooharsh, it is used to form hedges.Most of the specimens on thecampus have been heavily prunedand are quite globular in appear-ance as a result of this.

1-3.

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Olea europea - Common Olive

Native to the Mediterraneanarea and western Asia, this smalltree is cultivated both forlandscaping and for its ediblefruit. Its growth form is moreshrub-like than tree-like and itsgrey-green evergreen foliagemakes it a desirable garden plant.

Apocynaceae - Dogbane Family

Nerium oleander - Oleander

Native to the Mediterraneanand planted as a shrub all overthe campus. The species producesred or white flowers and is exten-sively planted as a decorativeshrub along the center strip ofmost of the freeways in California.If left alone, it will grow to treesize. Caution: the flowers, leavesand young shoots may be deadly poi-sonous if eaten.

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GLOSSARY

Acorn - The one-seeded fruit of oaks, with a cap-like basesurrounding a portion of the nut.

Acute - Sharply tapering to a point at the tip.

Alternate - Leaves arranged one at each position (node) ona stem.

Awl-shaped - Small, narrowly triangular leaves.

Axil - The angle formed between two structures (the leaf andstem, or veins in leaves, etc.).

Axillary - Found in axils.

Berry - A fleshy, multi-seeded fruit (tomato, for example).

Blade - The flat, expanded portion of a leaf.

Bract - A modified leaf found near a flower or reproductivestructure.

Branch - A small secondary stem, or the larger divisions ofsecondary stems.

Branchlet - The smallest divisions of a branch.

Catkin - A dense, spike-like inflorescence of unisexual flowers(ament).

Compound leaf - A leaf with the blade divided into leaflets.

Cone - The reproductive structure of most conifers, composed ofwoody bracts, usually spirally arranged.

Cordate - Heart-shaped.

Deciduous - Falling away; not evergreen.

Decurrent - A portion of a leaf which runs alongside the stem.

Dentate - Toothed (usually large tooth-like structures on a leafmargin).

Dioecious - Having unisexual flowers or reproductive organs, withseparate sexes found on different individuals.

Drupe - A fleshy, one-seeded fruit (a cherry or olive, forexample).

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Entire - Leaf margin without teeth or lobes.

Fruit - The ripened ovary and any accessory structures, producedby an angiosperm.

Glabrous - Smooth, without hairs.

Glaucous - Covered with a downy material which easily rubs off.

Globular - Rounded, like a globe.

Herbaceous - Soft-stemmed.

Lanceolate - Lance-shaped; widest at base and gradually taperingto a point at the apex or tip.

Leaflet - A division of a compound leaf.

Legume - A fruit of the pea family; a pod-shaped fruit such as apea or bean.

Linear - Narrow and flat with parallel sides, such as a blade ofgrass.

Lobe - A segment of a leaf, usually rounded.

Midrib - The central, major vein in a leaf.

Monoecious - Having unisexual flowers, but both male and femalefTowers or reproductive structures occuring on the sameindividual plant.

Needle-Like - Long, thin pointed leaves, usually round or angularin cross-section.

Net-veined - Veins joined together like a fish net.

Node - The position on a stem where leaves, buds, etc. occur. Thespace between nodes is called an internode.

Nut - A one-seeded, dry fruit with a hard wall.

Oblique - Sides unequal - used especially to refer to bases ofleaves.

Oblong - Rounded, and two to four times longer than wide.

Opposite - Two leaves originating at a node.

Ovate - Egg-shaped, attached at widest end.

Palmate - Lobes, veins or leaflets which all originate at a centralpoint.

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Parallel-veined - Veins of a leaf running parallel to each otherfor the length of the leaf.

Parasite - An organism which takes its nourishment from anotherliving organism.

Peltate - Sheild shaped; attached near center (like an umbrella).

Persistent - Not falling off easily; evergreen.

Petiole - The stalk of a leaf.

Phyllodium - Expanded leaf rachis resembling a blade.

Pinnate - Veins, lobes or leaflets arising on opposite sides ofa mid-rib or central axis.

Pome - A fleshy, apple-like fruit.

Pubescent - Covered with short, soft hairs.

Rachis - The elongated axis of a compound leaf, equivalent tothe mid-rib of a simple leaf.

Scale - A thin, flaky structure covering an organ, or a structureresembling reptile scales.

Serrate - With sharp teeth directed toward the leaf tip.

Sessile - Without a stalk of any type.

Simple leaf - A leaf with an undivided blade.

Sinus - The space between lobes in a simple lobed leaf.

Stipule - An appendage at the base of the petiole of a leaf,usually leaf-like or spiny.

Truncate - Squared off at the tip.

Undulate - A "wavy" leaf margin.

Vein - Elongated bundle of vascular tissue in a leaf.

Whorled - Three or more leaves at a node.

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USEFUL REFERENCES

Gleason, H. A. and Cronquist, A. 1964. The Natural Geographyof plants. Columbia University Press, New York, New York.

Harrington, H. D. and Durrell, I. W. 1957. How to IdentifyPlants. Swallow Press, Chicago, Illinois.

Jepson, W. L. 1925 A Manual of the Flowering Plants ofCalifornia. Associated students Store,University of Cali-fornia,Berkeley, California.

McMinn, H. E. and Maino, E. 1935. Pacific Coast Trees. 2ndedition, 1967. University of California Press, Berkeley,California.

Metcalf, W. 1960. Native Trees of the San Francisco Bay Region,University of California Press.Berkeley,California.

Porter, C. L. 1959. Taxonomy of Flowering Plants. W. H.Freeman and Company, San Francisco, California.

Thomas, J. H. 1961. Flora of the Santa Cruz Mountains ofCalifornia. Stanford University Press,Stanford, California