A Guide to the Trees of Menlo College

a guide to the

TREES OF MENLO COLLEGE

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 the botany student the methods and procedures involved in identifying plants, and to familiarize the student with the species of trees found on the campus of Menlo School and College. Over 70 species of trees are represented on the Menlo campus. Of these, most are identified in this manual. Identi- fication of trees in this book is based primarily upon leaf structure and arrangement. Some species are difficult to identify precisely without studying floral structure, or because their growth form may be atypical because of such factors as pruning, local environmental conditions, or because of the exis- tence of a great variety of horticultural forms. In these instances the trees are identified to the genus and are treated collectively (willows, cherry, plum, for example). Only fifteen species of the trees found on the Menlo campus are native to the San Francisco Bay Area. The rest are introduced and represent types from many parts of the United States and the world. This gives the student an opportunity to become familiar with a wide variety of families of trees. TREES

Plants are generally classified into two major groups: the Thallophyta, simple bodied plants with unicellular reproductive structures, and the Embryophyta, those plants which have more complex bodies, multicellular reproductive organs and produce an embryo in their life cycle. This latter group may be arbitrarily divided into non-vascular and vascular plants. The vascular plants 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 woody plants. VJoody plants are those which have vessels in which the cell walls have, in addition to cellulose, a chemical called lignin which makes them quite hard and rigid. Woody plants are found in the classes of seed plants known as Gymnospermae, which are all woody, and the Angiospermae or flowering plants which in- clude some woody and herbaceous plants. The woody plants are generally described as being either trees or shrubs. Although there is some overlap, a tree is usually considered to be a woody plant with a single main stem which is over fifteen feet tall at maturity. A shrub is usually a multiple stemmed woody plant which, at maturity, is less than fifteen feet tall. There is sometimes difficulty in determining whether a specimen is a small tree or a large shrub, and often the terms "tree-like" or "shrub-like" are used because of this. The plants described in this manual are, with few exceptions, limited to those which normally exist as trees by the above definition. 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 pictures; 3) Compare it to herbarium specimens if they are available; 4) Use a key. Use of the keys in this book requires a rudimentary 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 animal taxonomy to identify groups or kinds of organisms. Many types of keys are used, and these are normally constructed so that organisms are arranged into groups with similar characteristics, and then broken down into smaller groups which have more specific characteristics that distinguish the groups from one another. Eventually individual types are selected by traits which distinguish them from other kinds. Most keys offer the user alternatives of choices. Keys are usually dichotomous, that is, the choices are paired. Each choice leads either to another pair of alternatives or to a final identification. The keys in this book are strictly dichotomous. Each pair of choices is numbered. Each choice is, essentially, a description of a characteristic or group of characteristics with which the specimen to be identified should be compared. If the specimen fits the description for choice number one in a key, the student should then go on to the next description which immediately follows the first. If the specimen does not fit, then the student should go on to the second choice number one. It is always wise to read both members of a pair of descriptions and select the most accurate. "Keying" is more an art than a science. As one progresses through the keys in this manual, he is led from one set of alternatives to another, and ultimately to the genus of the plant in question, with a page reference. In turning to that page he will find a description of the species of 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 of the 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, surrounding branchlets 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, in bundles of 2 to five Pinus Page 17 2. Leaves usually less than 2 inches long, in clusters of more than 5 needles (some single needles 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 1-1/2 inches 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 arranged and overlapping giving smaller branchlets a rope-like appearance Araucaria Page 14 4. Leaves linear or narrowly lanceolate 6. Leaves, when removed, leaving round scars on branches; 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, leaving short distinct pegs on branches when falling Picea Page 16 7. Leaves more flexible, often pointed but not stiff and prickly to the touch 8. Leaves attached to branches by decurrent bases 9. Leaves with short petioles, continuous with bases, falling singly .... Taxus Page 14 9. Leaves sessile, persistent, falling with branchlets Sequoia Page 15 8. Leaves with distinct petioles attached by stalk-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 longer than broad Libocedrus Page 18 2. Leaves 2 at a node, internodes about as long as broad

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

3. Cones globular, peltate; branchlets less than 1/12 inch thick Cupressus Page 18 1. Branchlets not forming flat sprays

4. Leaves more awl-shaped than scale-like, spirally arranged, 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 hanging against stems Washingtonia Pj-ge 21

4. Shorter plants, stems hairy and covered with old leaf bases

5. With a single main trunk; petioles armed with long sharp spines Chamaerops Page 20 X 5. With several stems branching very near baser,fI petioles^ y often 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 a drupe, 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; plant usually 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, lateral veins 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 inches wide; 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 or less wide, often in whorls of three.... Nerium Page 36 4. Leaves ovate- lanceolate, more than 1 inch wide •• 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 and leathery 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 stipule at 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 leathery capsule; 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 same plant; 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; fruit 1-1/2 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 sticky substance Pittosporum Page 3 0 17. Fruit a berry, 1/4 to 1/2 inch long; leaves 2 to 4-1/2 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 with dichotomous 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 to 12 inches long Ficus Page 28 22. Leaves not rough to the touch, shorter

23. Leaf lobes entire, pointed at apex (most of the leaves on 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-like nutlet Myrica Page 22 29. Some leaves entire; fruit a drupe Prunus Page 31 25. Leaves deciduous 30. Plants dioecious; fruit a capsule; seeds with tufts of 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 composed of 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

TREES OF MENLO COLLEGE

On the following pages, the major tree species found on the campus of Menlo College are described. The descriptions are in- tended to aid the student in his identification of the plants and to provide the reader with some facts relating to the natural distribution of these trees and some of the uses which man has made of them. 14

CLASS GYMNOSPERMAE

Ginkgoaceae - Gingko Family

Ginkgo biloba - Maidenhair Tree This tree is native to China, It is a broad-leaved deciduous gymno- sperm with sparse, graceful ascending branches. It is widely cultivated and the only living member of its family. This species is dioecious and the fleshy seed (often mistakenly called a fruit) produced by the female gives off an extremely disagreeable odor when ripe. This tree is relatively free of insect pests which makes it quite desirable as a landscape specimen.

Taxaceae - Yew Family

Taxus baccata - English Yew A densely branched tree, native to Europe, Asia and northern Africa which may be shaped by pruning and used for ornamental purposes. There are a number of cultivated varieties.

Araucariaceae - Araucaria Family

Aracauria excelsa - Norfolk Island Pine This tree is a member of the same genus as the Monkey-Puzzle tree and the Bunya-Bunya tree which are native to Chile. It is native to Norfolk Island and is the most widely cultivated species of Arau - caria in California. AlthougFTt may reach 70 or more feet in height, it is a very popular potted plant and is used in bonsai gardening. In spite of the common name, it is not a pine. 15

Taxodiaceae - Redwood Family

Sequoia sempervirens - Coast Redwood The genus Sequoia is named after a Cherokee Indian chief, Sequoyah. The specific name - sempervirennpervi] s - means "always living"ring".. The Coast Redwood is one of the longest-lived trees in the world, many specimens over 3,000 years in age. It is also the tallest of trees, its closest competitors being the Giant Sequoia, Douglas fir, and some Eucalyptus trees from Australia. The species ranges from the Big Sur area of California to southern Oregon along the coast, the finest specimens being found in northern California. It is extremely dependent upon fog and rarely germinates from seed.

Sequoiadendron gigantea - Giant Sequoia, or Big Tree The most massive of all living things. This species is found naturally only in 32 isolated groves on the west slopes of the Sierra Nevada in Califor- nia. It is dependent upon fire for its survival, as this is necessary for thinning out the forest shrubs which compete with its seedlings. Unlike the coast redwood, its wood makes very poor quality lumber. 16

Pinaceae - Pine Family

Cedrus - Key to the species. Pendulus branchlets; leaves up to two inches long C. deodara Branchlets rarely pendulous; leaves usually less than 1-1/4 inches long C. atlantica Many trees are commonly called "cedar". None of these is native to North America. Only members of the genus Cedrus are true cedars, and two of the three species are planted on the Menlo campus.

Cedrus deodara. Deodar Cedar Native to the Himalayas. Fre- quently planted throughout California as an ornamental tree in areas where there is not prolonged freezing. A beautiful tree, with graceful hanging branches.

Cedrus atlantica. Atlas Cedar A large tree, with large upright cones. Native to the Atlas Mountains of Northern Africa, it is widely planted throughout the Pacific Coast from British Columbia to San Diego.

Picea pungens - Colorado Blue Spruce A tall tree, often 100 feet high, and native to the Rocky Moun- tains. It is pyramidal in general shape with blue-green foliage. The Colorado State Tree. 17

Pinus Several species are found on campus and are difficult to distinguish without cones present. Only one species is described here, as there are several specimens on the campus which occur naturally.

Pinus radiata - Monterey Pine Native to central coastal Cali- fornia. This tree often grows to over 100 feet in height, and may be recognized by its dark green foliage, irregular rounded crown and stout oblique cones which persist on the stems for up to 12 years. There are 3 leaves (rarely 2) to a bundle. This tree is often planted for landscape purposes and (questionably in some 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 important lumber tree in North America. It is found throughout the west, especially in the mountains from the Rockies to the Pacific Coast. It achieves its best growth in the Pacific Northwest and is second only to the Coast Redwood in height. It is the primary source of material for rough housing construction, ply- wood, etc. It is not a fir (the true firs belong to the genus Abies) but closely resembles the Hemlock. The name Pseudotsuga means "false hemlock".It is easily recognized by its cones, the bracts looking like the hind legs and tail of mice going into their holes. 18

Cupressaceae - Cypress Family

Cupressus - Cypress There are several species of cypress on the campus. These are, however, difficult to distinguish because of the effects of pruning, and, because mature cones aren't readily available to the student, they will be treated collectively here. Two species of cypress occur as native to the Santa Cruz Mts.: Monterey Cypress, which is widely planted as a windbreak and exists naturally in a grove at Point Lobos on the Monterey Peninsula, and Santa Cruz Cypress, which is found only in a few isolated areas between Santa Cruz and San Francisco.

Libocedrus decurrens - Incense- Cedar Not a true cedar, this tree bears a superficial resemblance to the Giant Sequoia and is often mistaken for it in the Sierra Nevada where it is native. It is also found throughout the higher coast ranges from Oregon to Baja, California. It is quite aromatic and a handsome tree. It is easily identified by its unusual cones which split open along a central plane. 19

Two species are found on campus: Thuja occidentalis - American Arbor- vitae (tree of life), which is a small tree, often shrub-like, and native to northeastern United States and southeastern Canada, and Thuja plicata - Western Red-cedar, a forest tree of the Pacific states often attaining a height of 200 feet. It is found from Alaska to Humboldt County, California and is planted for its stately beauty. The early Indians carved canoes from the trunks of these trees and also used them for construction of houses. The wood is easily carved and was a major source of material for totem poles. In modern use, its greatest importance to the lumber and building industries is that it is the source of 80 percent of the shingles and clapboards used in home construction. 20

CLASS ANGIOSPERMAE

Subclass Monocotyledonae The most advanced members of the plant kingdom are the mono- cotyledonous angiosperms. They are, however, traditionally listed before the dicots in most floras. Most of the monocots are 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 are widely planted in California as ornamentals. They are palm-like but can be distinguished from palms by their simple leaves. The name Dracaena is after the female dragon^Tn~e dried juice from these plants supposedly resembles dragon's blood. The North American counterpart of these trees is the Joshua Tree"of the southwestern deserts (Yucca brevifolia).

Palmaceae - Palm Family

Chamaerops humilis - Hair Palm

Chamaerops comes from the Greek for"dwarf bush". This species is very hardy and is the only palm native to Europe where it is found in the Mediterranean region.

Trachycarpus excelsa - Windmill Palm

This plant is native to central and eastern China. It is a slender pain rarely over 30 feet hinh and one of the hardiest culti- vate.1 in California. 21

Washingtonia - There are 2 species of this genus which is named after George Washington: W. filifera, Cali- fornia Washington Palm, which is native to the deserts of southern California and is heavier and stouter than its close rela- tive, W. gracilisf Mexican Washington Palm, which is native to Baja, California. This species is distinguished from W. filifera by its more slendeF trunk,shorter petioles and more extensively divided leaves.

Phoenix canariensis - Canary Island Date Palm This tree is extensively planted in California and is very hardy. The foliage is very dense and spreading. The fruit of this species, by the way, is not edible.

Jubaea spectabilis - Syrup Palm, Monkey-Coconut Native to Chile. One of the most beautiful of the palms, with a smooth, massive trunk up to 30 feet high and 3 to 5 feet in dia- meter. The fruits are small and resemble small coconuts, hence the name Monkey-Coconut. The Chilean natives prepare a mixture called "palm-honey" from the sap of the stem. 22

SUBCLASS DICOTYLEDONAE This is the largest major group of plants, with approximately 200,000 species. Most of these are herbaceous, as are 99 percent of the monocots. Except for the gymnosperms, which are all woody and a few monocots (palms, etc.), the vast majority of trees belong to this group of flowering plants.

Salicaceae - Willow Family

Populus balsamifera - Cottonwood Native from northeastern North America to the Rockies, and occasionally planted in California as a street or park tree, this species is a source of pulp for the paper industry. The wood is rather soft and of poor quality for construction. It is used, however, as a filler material covered by veneers for inexpensive furniture.

Salix sp. - Willow The genus Salix is a difficult one in terms of identifying the species (with a few exceptions) because of the necessity to have flowers present for correct identification, and because of the variety of growth patterns that may exist within a single species. Many of the specimens on the campus have been rather severely and extensively pruned so that their growth habit is atypical. The willows as a group are very interesting in terms of the uses to which they have been put. Because of their very rapid growth, they are often planted to prevent erosion along streams and highways.

Myricaceae - Myrtle or Sweet-Gale Family Myrica californica - California Wax-Myrtle An evergreen, small tree or, in its natural state, a large shrub. Found in the coast ranges from Washington to Santa Monica. 23

Juglandaceae - Walnut Family

juglans regia - English Walnut juglans is a contraction of "Jove's glands", a fairly accurate if not puritanical description of the husked fruit. "Jove's glands" is actually a corruption of the Latin Jovis, Jupiter, and glans, nut. This tree is the source of the commercial walnut and in orchards is usually grafted to the stem of Juglans hindsi, the California Black Walnut, which has a 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 bark is white, the leaves resemble those of B. papyrifera and the fruiting catkins are about 1 inch long. There is a great variety of horticultural 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 recognized by the white, peeling bark. The fruiting catkins are 1-1/2 to 2 inches long. Native to Canada and eastern United States, this is the tree which the Indians used for building canoes (the bark was used to cover a frame built of flexible wood strips from several species of trees or shrubs) and for primitive paper. The bark of this tree, because of its high resin content, is an ideal source of kindling for fires built in snow when firewood supplies in the forest are wet. It burns very readily and at a very high temperature. 24

Fagaceae - Beech Family

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

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

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

Key to species 1. Leaves not lobed, evergreen

2. Leaves green, glabrous on both surfaces with tufts of axillary hairs beneath, leaf margins toothed 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, lobes spine-tipped.

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

4. Leaves pubescent beneath* no axillary hairs Q. kelloggi 25

Quercus agrifolia - Coast Live Oak

The specific name agrifolia is believed to be the result of a printer's error which has been per- petuated since the tree was first described. The original word was probably aquifolia - meaning "holly- leaved" as the leaves resemble those of the holly tree. This species is the "Menlo Oak" which is displayed on the school seal. The tree is evergreen, as are many of the Cali- fornia oaks, and is abundant throughout the coastal valleys and foothills of California. This oak is probably the world's most photo- graphed tree, as groves of it form the backdrop for great numbers of motion pictures depicting every- thing from "Robin Hood" to cowboys and 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 North African native is cut into corks for a great variety of uses. Many of these are planted as ornamentals around California. In a conversa- tion with Mr. Leon Loofbourow, he mentioned that in the early 1940's, the government surveyed the loca- tion of all Cork Oaks in the local area for possible use as a cork supply for life preserver's to be used during World War II should the need have arisen. 26

Quercus lobata - Valley Oak, Roble Found throughout California from the foothills of the Sierra Nevada to the coast. From a dis- tance, the characteristic thick checkered gray bark distinguishes this large graceful tree. It is deciduous, and in the winter the mistletoe, which parasitizes the oak, becomes conspicuous. The acorns of this oak, as well as others, were a staple food of the California Indians. The nuts were ground, leached of the tannins present in them, and used as a source of flour for baking, or served as a mush. Because the Valley Oak grows in the valleys where the soil tends to be richest, it has often been sacrificed to make room for agriculture.

Quercus kelloggi, Black Oak, and Quercus coccinea, Scarlet Oak are very difficult to distinguish when immature, and the few specimens on campus are relatively young. The oaks generally are divided into 2 major groups - the black oaks ("live" oaks, Scarlet Oak and Black Oak belong to this group), have lobed or unlobed leaves which are spine- tipped, whereas the White Oak leaves, if lobed, do not have spines on the leaf edges. 27

Ulmaceae - Elm Family

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

Key to species 1. Leaves evergreen several varieties of ornamental elms 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 Europe often planted as a park and shade tree.

Ulmus americana - White Elm, American Elm Native to eastern United States. 28

Moraceae - Mulberry Family

Ficus carica - Fig

Native to the area around the Mediterranean. Many varieties of horticultural forms have been developed for their edible fruits. The leaves of this tree are very large, palmately veined and lobed. The leaves are gently toothed or wavy along the margins and slightly rough 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 primitive of the living families of flowering plants. The buttercup family is probably ancestral to the monocots and to the rest of the dicots, but is placed here because, traditionally, the petal-less flowering plants have been listed first in taxonomic lists or floras.

Liriodendron tulipifera - Tulip Tree

So called because of the resemblance of the leaves in silhouette to the flower of the tulip. The tree is native in the forests from southern New England to Florida.

Magnolia sp. - Magnolia

There are several species of magnolia on campus, but these will be treated here collectively. As a group they have fairly large, thick leathery leaves and huge, showy flowers with 3 petal-like sepals and 6 to 15 petals and numerous pistils and stamens. The fruit is a large, usually upright, cone- like structure. The various species are native to eastern and southern United States, Central America and eastern Asia. They are frequently planted in Califor- nia for their showy flowers which bloom throughout the summer. 29

Lauraceae - Laurel Family

Cinnamomum camphorurn - Camphor Tree

A small tree with thin, light green, glossy evergreen leaves. The leaves, when crushed, have the odor of camphor. Many of the members of the laurel family are extremely aromatic and the source 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, shrub with small purple berries for fruits. Native to southern Europe and southwestern Asia.

Persea americana- Avocado This tree is native to tro- pical regions of the western hemisphere. It is greatly branched, up to 60 feet high, with large oblong leaves (to 10 inches in length). It is extensively planted in southern California for its large fleshy fruits. Menlo can thank Mr. Russell, College Direc- tor, and his wife for its fine specimen which they grew from seed in a jelly jar a number of years ago.

Umbellularice californica - Cali- fornia Laurel Oregonians call this tree "Ore- gon Myrtle". Obviously the result of local pride, as it is the source of myrtlewood which is used for all kinds of things from knick-knacks to cabinetry, but it really belongs to California. In California it is known as Laurel, California Bay, or Bay Laurel. It is closely related 30

to the European Bay trees, the leaves of which are used as a spice and seasoning. The spicy odor of the leaves of this tree is very much evi- dent to one standing near it in the woods. In this area it is a large, graceful evergreen tree, while in Oregon it tends to be rather stunted. It is native from southwestern Ore- gon through the Coast Range to southern California and in the foothills of the Sierra Nevada to 3000 feet.

Pittosporaceae - Pittosporum Family

Two species on campus:

P_. undulatum and P_. tenuifolium.

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

P. tenuifolium is usually a large shrub with dark green leaves, and P_. undulatum is a small tree with yellow-green leaves with undulate (wavy) margins. Native to Australia and New Zealand. 31

Hamamelidaceae - Witch-Hazel Family

Liguidambaiqu r styraciflua - Sweet Gu: This species is native to the eastern half of the United States, and into Mexico where it is never abundant but scattered throughout the forests. Its wood is used extensively for furniture but it is not an important lumber tree. The alternate, star-shaped palmately lobed leaves with serrate edges help to identify this species.

Rosaceae - Rose Family This family is often treated by some taxonomists as several separate families - the Rosaceae or Rose family, the Amygdala- ceae or Peach family, and the Malaceae or Apple family. Here they are treated as one group.

Crataegus oxycantha - English Hawthorn Native to Europe and North Africa, there are many varieties of hawthorn grown as ornamentals in the United States. One of the specimens on the Menlo campus is almost thornless, although the species normally has numerous stout thorns about 1 inch long. The leaves turn bright red in the fall. The tree is quite small, rarely over 15 feet high.

Prunus To this genus belong the plums, peaches, cherries, etc. Because of the great variety of horticultural species and varieties developed for agriculture and landscaping, only one species is described below, although several are found on campus. The genus represents a major fruit industry in California, especially in the Santa Clara valley which is world famous for its prunes.

Prunus cerasifera - Purpleleaf Plum A horticultural variety planted as a lawn and street tree for its colorful reddish-purple leaves. 32

Malus

This is the apple genus. An important food source. Again, the individual species will not be described because of the variety of horticultural forms which are planted both commercially and for landscaping. The trees are usually rather gnarled and twisted in their growth patterns and make interesting garden specimens.

Fabaceae - Pea Family

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

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, pale green; small tree or large shrub A. longiflora

Acacia melanoxylon - Blackwood Acacia

A handsome tree with dark green leaves and dark grey furrowed bark. Native to Australia and planted throughout coastal California as a shade tree.

Acacia longiflora - Sydney Golden WaTEle

Native to Australia, very "willow-like" in its overall appearance, and planted as an ornamental tree in California. The leaves of the above Acacias are not leaves in the true sense, but phyllodia; the expanded, flattened leaf rachises. 33

Acacia decurrens var. dealbata - Silver Wattle Native to Australia. At maturity, this is a large tree (up to 60 feet high) with very small leaflets which are grey green and give the leaves a feathery appearance. This tree is widely planted for its aesthetic value.

Cercis canadensis - American Redbud

Native to eastern United States and occasionally planted in California. A common understory tree in the eastern forests, it has no great commercial value although it is sometimes used for furniture and cabinet making.

Cladrastis lutea - Yellow-Wood

Native to southeastern United States. This tree is occasionally cultivated for its foliage and clusters of white flowers which appear in the spring. It is relatively rare in the wild state where it is of minor importance as an understory species.

Robina pseudoacac ia - Black Locust

A tree of the eastern United States which is frequently planted as a shade tree. It withstands drought and poor soils quite well. The wood is very hard and durable which makes it a good material for fine furniture. The extensive fibrous root system of this tree makes it extremely useful when planted in erosion control pro- grams. 34

Rutaceae - Rue Family

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

Anacardiaceae -'Sumac Family

Schinus molle - California Pepper Tree

Native to Peru. This species is dioeceous. If you are adven- turous you might collect the little red "peppercorns" or fruits of the female of this species, dry them and grind them in your pepper mill. It makes an interesting seasoning. The tree is planted in the United States for its picturesque "weeping willow" appearance.

Aquifoliaceae - Holly Family Ilex aguifolium - English Holly

Native to Europe and Asia. Used in this country primarily as an ornamental because of its dark green, glossy foliage and red berries which persist through the winter. There are several species of holly native to eastern United States but which are rarely cultivated in the west. This species is often used in making Christmas wreaths.

Aceraceae - Maple Family

Acer palmatum - Japanese Maple There are two species of maple native to the San Francisco peninsula. Neither is found on campus. Ours was "made in Japan" or at least its ancestors were. This species is used strictly as an ornamental. Native to Japan and Korea. 35

Sterculiaceae - Sterculia Family

Sterculia

There are 2 species of this genus on campus: S_. diversifolia, Black Kurrajong, and S. acerifolia, Flame Tree or Bottle Tree"! The 2 species are difficult to distinguish. S. diversifolia has leaves 2 to 3 inches long, while S. acerifolia has leaves which are" usually over 4 inches long (see sketches). Both are native to Australia and are 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 native to eastern United States. Several agricultural varieties have been developed for their fruit which is rather fleshy.

Oleaceae - Olive Family Ligustrum lucidum - Glossy Privet 1-3. This species is native to China and Japan and is planted throughout the U.S. In this area it grows as a small tree and is used in landscaping quite extensively. In more severe climates, provided the winters aren't too harsh, it is used to form hedges. Most of the specimens on the campus have been heavily pruned and are quite globular in appearance as a result of this. 36

Olea europea - Common Olive Native to the Mediterranean area and western Asia, this small tree is cultivated both for landscaping and for its edible fruit. Its growth form is more shrub-like than tree-like and its grey-green evergreen foliage makes it a desirable garden plant.

Apocynaceae - Dogbane Family

Nerium oleander - Oleander

Native to the Mediterranean and planted as a shrub all over the campus. The species produces red or white flowers and is extensively planted as a decorative shrub along the center strip of most of the freeways in California. If left alone, it will grow to tree size. Caution: the flowers, leaves and young shoots may be deadly poi- sonous if eaten. 37

GLOSSARY Acorn - The one-seeded fruit of oaks, with a cap-like base surrounding a portion of the nut. Acute - Sharply tapering to a point at the tip. Alternate - Leaves arranged one at each position (node) on a stem. Awl-shaped - Small, narrowly triangular leaves. Axil - The angle formed between two structures (the leaf and stem, 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 reproductive structure. Branch - A small secondary stem, or the larger divisions of secondary 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 of woody 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 leaf margin). Dioecious - Having unisexual flowers or reproductive organs, with separate sexes found on different individuals. Drupe - A fleshy, one-seeded fruit (a cherry or olive, for example). 38

Entire - Leaf margin without teeth or lobes.

Fruit - The ripened ovary and any accessory structures, produced by 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 tapering to 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 a pea or bean.

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

Lobe - A segment of a leaf, usually rounded.

Midrib - The central, major vein in a leaf.

Monoecious - Having unisexual flowers, but both male and female fTowers or reproductive structures occuring on the same individual plant.

Needle-Like - Long, thin pointed leaves, usually round or angular in cross-section. Net-veined - Veins joined together like a fish net.

Node - The position on a stem where leaves, buds, etc. occur. The space 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 of leaves.

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 central point. 39

Parallel-veined - Veins of a leaf running parallel to each other for the length of the leaf. Parasite - An organism which takes its nourishment from another living 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 of a 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 to the mid-rib of a simple leaf. Scale - A thin, flaky structure covering an organ, or a structure resembling 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.

USEFUL REFERENCES

Gleason, H. A. and Cronquist, A. 1964. The Natural Geography of plants. Columbia University Press, New York, New York. Harrington, H. D. and Durrell, I. W. 1957. How to Identify Plants. Swallow Press, Chicago, Illinois. Jepson, W. L. 1925 A Manual of the Flowering Plants of California. Associated students Store,University of Cali- fornia,Berkeley, California. McMinn, H. E. and Maino, E. 1935. Pacific Coast Trees. 2nd edition, 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 of California. Stanford University Press,Stanford, California