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JJuneune 1122, 22008008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

FIELD GUIDE TO THE COMMON RIPARIAN TREES AND SHRUBS OF THE LOWER TRINITY RIVER

Welcome-

INTRODUCTION This fi eld guide to the common riparian trees and shrubs of the Trinity River is the product of working with many folks who are interested in the common trees and shrubs growing along the Trinity River. This guide includes those trees and shrubs (i.e., riparian hardwoods) that would commonly be encountered within the mainstem Trinity River between Lewiston Dam (1,870 ft [570 m]; River Mile 112.0), and the Trinity River’s confl uence with the Klamath River at Weitchpec (320 ft [98 m]; River Mile 0.0). You will not need any special equipment (i.e., a handlens or microscope); the characteristic features used in identifying hardwoods can be seen without magnifi cation.

This guide includes both native and exotic hardwood species. Exotic species are included to increase our awareness of potential pests in the mainstem and be able to manage an exotic plant infestation before it becomes widespread. The Trinity River is fortunate not to suffer the blight of Giant Reed (Arundo donax) and only minimally suffers from isolated black locust trees and localized tree of heaven infestations.

For those familiar with plant identifi cation, the identifi cation portion of the guide is an indented dichotomous key. The key can be used to identify mature riparian hardwood specimens along the river below Lewiston Dam. I did not write this key to identify seedlings, but with familiarity with each species, seedlings could be identifi ed. I assume that people are familiar with common terms associated with plant characteristics (petioles, bud scales, serrated margins etc.). However, at the end of the guide, we have included an illustrated glossary to assist with the terminology used to describe the identifying characters in the key.

The key is broken into two major branches, plants that are fl owering, and plants that are not. These two sections of the key will allow you to identify these hardwoods if fl owers are not present, or you are not certain what the fl owers look like. Hardwoods are listed alphabetically using the scientifi c names in the description section.

Ideally, all the characteristics used in each key step would be present on the plant so the user could use a combination of the characteristics to make the decision in each key step. We listed plant characteristics in each key step by order of consistency and confi dence in identifying each species of hardwoods. The fi rst characteristic is most consistent and generally unique to that species or plant group (e.g., single bud scales in Salix vs. multiple bud scales in Populus) and therefore is best at being able to separate the plant from others. The second characteristic is separated from the fi rst with a semicolon and is less consistent often overlapping with other species or genera. The third characteristic can be used with less confi dence. If one of the characteristics used is not present then the next characteristic can be used, just with less confi dence. It is always best to use as many characters as possible to make the decision in each step.

Updated June 12, 2008 2 McBain and Trush, Inc. 2007

Frequently there are grumblings about how diffi cult willows are to identify. This fi eld guide attempts to shed some light on those annoying willows. Willows are characteristically variable both within each plant and within the population. There are techniques that can be useful when using this key to identify willows. A visual assessment of the whole tree or shrub capturing the range of variation expressed by the plant is the most helpful technique. Be sure to look at branches that are in direct sunlight, in the shade, young shoots, and mature shoots. Use the middle of this years shoot for your observations (Skortsov 1968). The lowest portion of each branch are often malformed leaves because they are from the early season. The tips of the branches are where the active growth is occurring and INTRODUCTION are also often misshaped. The variability in the base and tips of branches makes leaves at these two locations the most variable in shape. In a pinch, the litter beneath the plant is useful in providing characteristics that might be seasonally available, but not always present (e.g., trying to detect leaf shape in winter or early season, fi nding fl owering catkins after fl owering and seed dispersal has passed etc.).

Any errors or omissions are solely my own. I have relied heavily on the works of George W. Argus and my own fi eld experience for the willow portion of this guide (I am very grateful to Dr. Argus for his comments). However, the many other included species are a compilation and synthesis of the works of many; I owe them more than I can ever acknowledge. Please let me know if you have advice, insight, comments, compliments, criticisms, questions, revisions, or wish to see something else added or addressed. Good luck, be patient with yourself, remember to wear your sunscreen, and above all HAVE FUN!

John H. Bair

Riparian Botanist McBain and Trush Inc PO Box 663 Arcata, CA 95521

3 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

GUIDE TO IDENTIFYING TRINITY RIVER RIPARIAN HARDWOODS

1 Riparian tree or shrub obviously with fl owers

2 Plants with individual male and female fl owers (monoecious) or, fl owers with both male and female fl ower parts

3 Plants with fl owers that have both male and female parts (fl owers perfect), fl ower typical of pea family ...... Robinia pseudoacacia

3’ Plants with individual male and female fl owers on one individual

4 Plants with simple leaves, fruiting structure looks like a small pinecone;

KEY fruit inside this “pseudo-cone” is a winged nutlet ...... Alnus rhombifolia

4’ Plants with leaves consisting of many leafl ets attached to a central stalk (compound leaf), fruiting structure consists of a fl eshy layer enveloping a hard nut ...... Juglans californica var. hindsii

2’ Plants with male or female fl owers on different plants (dioecious)

5 Plants with leaves consisting of many leafl ets attached to a central stalk (compound leaf)

6 Compound leaves with 13-25 leafl ets, no obvious terminal leafl et, strong odor when crushed ...... Ailanthus altissima

6’ Compound leaves with 5-7 leafl ets, obvious terminal leafl et, no strong odor when crushed ...... Fraxinus latifolia

5’ Plants with simple leaves

7 Catkin hanging (pendulous), not borne on this year’s leafy shoot, individual fl owers subtended by cup shaped disk

8 Ovary and young fruit hairy, winter buds fi nely ciliate, odorous and resinous ...... Populus balsamifera ssp. trichocarpa

8’ Ovary and young fruit hairless (glabrous), winter buds not fi nely ciliate, not odorous, and resinous ...... Populus fremontii

7’ Catkins upright, or if hanging (pendulous) borne on this year’s leafy shoot, individual fl owers not subtended by cupshaped disk

9 Plant with male fl owers present

10 Bud scale free ...... Salix laevigata

10’ Bud scale not free (or cannot tell at this time)

11 Stamen 1, leaf blade underside silky wooly hairy ...... Salix sitchensis

11’ Stamens 2 or more, leaf blade underside sparsely to densely hairy

12 Stamen 2

Updated June 12, 2008 4 McBain and Trush, Inc. 2007

13 Catkins present without leaves, borne on last years woody branch ...... Salix lasiolepis

13’ Catkins developing with leaves, borne on this year’s leafy shoot

14 Leaf blade strap like (linear), with no glands on the margin (+/- 1-2 glands), densely hairy \ ...... Salix exigua

14’ Leaf blades with one point that is wider than the rest of leaf, margin with some glands (> 1-2 glands), leaf blade without hair (glabrous) ...... Salix melanopsis

12’ Stamens greater than 2 KEY

15 Glands at leaf base junction with leaf stalk (petiole) numerous and warty, leafy structures around the petiole junction with the branch glandular ...... Salix lucida ssp. lasiandra

15’ Glands at leaf base junction with leaf stalk (petiole) not obvious, The leafy structures around the petiole attachment with the branch are not obviously glandular ...... Salix laevigata

9’ Plant with female fl owers present

16 Bud scale free ...... Salix laevigata

16’ Bud scale not free (or cannot tell at this time)

17 Ovary hairy

18 Leaf blade strap like (linear), densely hairy ...... Salix exigua

18’ Leaf blade widest toward tip (obovate to narrowly obovate), silky wooly hairy ...... Salix sitchensis

17’ Ovary not hairy

19 Catkins present without leaves, borne on last year’s woody branch, fl ower bract persistent after fl ower, bract generally densely hairy ...... Salix lasiolepis

19’ Catkins developing with leaves, borne on this year’s leafy shoot, fl ower bract not persistent after fl owering, bract generally sparsely hairy

20 Leaf blade strap like (linear), with no glands on the margin (+/- 1-2 glands), densely hairy ...... Salix exigua

20’ Leaf blades with one point that is wider than the rest of leaf, margin with some glands (> 1-2 glands), may or may not have some hair

5 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

21 Leaf widest at middle or near tip linear and narrow

22 Leaf blade silky wooly hairy ...... Salix sitchensis

22’ Leaf blade without hair (glabrous) ....Salix melanopsis

21’ Leaf widest near base not linear or narrow, leaf blade stalk (petiole) >5mm

23 Glands at leaf base junction with leaf stalk (petiole) numerous and warty, leafy structures around the petiole junction with the branch glandular .. Salix lucida ssp. lasiandra

KEY 23’ Glands at leaf base junction with leaf stalk (petiole) not obvious, The leafy structures around the petiole attachment with the branch are not obviously glandular ...... Salix laevigata

1’ Riparian tree or shrub with fl owers not obviously present

24 Plants with leaves consisting of many leafl ets attached to a central stalk (compound leaf)

25 Individual leafl ets oval, leafl et tip rounded, fruit a legume ...... Robinia pseudoacacia

25’ Individual leafl ets widest at base, leafl et tips pointed, fruits various

26 Compound leaves with 13-25 leafl ets, no obvious terminal leafl et, strong odor when crushed ...... Ailanthus altissima

26’ Compound leaves with 5-19 leafl ets, obvious terminal leafl et, no strong odor when crushed

27 Compound leaves alternate, leafl ets 11-19, fruiting structure consists of a fl eshy layer enveloping a hard nut ...... Juglans californica var. hindsii

27’ Leaves opposite, leafl ets 5-7, fruiting structure consists winged nutlet (achene) ...... Fraxinus latifolia

24’ Plants with simple leaves

28 Major veins in leaf raised on underside of leaf, fruiting structure maybe retained for 2+ years and looks like a small pinecone; fruit inside this “pseudo-cone” is a winged nutlet ...... Alnus rhombifolia

28’ Major veins in leaf not raised on leaf underside, fruiting structure annually deciduous and does not look like a small pinecone

29 Leaf shape triangular, or heart shaped, buds resinous constructed of multiple scales

Updated June 12, 2008 6 McBain and Trush, Inc. 2007

30 Leaf shape heart shaped, leaf edge serrated (like small hacksaw teeth), leaves dark green above light green below, covered with brownish resin ...... Populus balsamifera ssp. trichocarpa

30’ Leaf shape triangular, deeply toothed, leaves light green on both sides and not covered with brownish resin ...... Populus fremontii

29’ Leaf shape linear, spoon shaped, buds not resinous constructed of one scale

31 Bud scale free ...... Salix laevigata

31’ Bud scale not free (or cannot tell at this time)

32 Leaf blade strap like (linear), no one point along the leaf is consistently wider, with no glands on the margin

(+/- 1-2 glands), densely hair ...... Salix exigua KEY

32’ Leaf blades consistently with one point that is wider than the rest of leaf

35 Leaf widest at tip, leaf edge wavy and curved towards underside, leaf shape highly variable within one plant ...... Salix lasiolepis

35’ Leaf widest at the middle or below

36 Leaf widest at middle or near base linear and narrow (narrowly obovate, narrowly elliptic)

37 Leaf blade silky wooly hairy ...... Salix sitchensis

37’ Leaf blade without hair (glabrous) ...... Salix melanopsis

36’ Leaf widest near base not linear or narrow (lanceolate)

38 Glands at leaf base junction with leaf stalk (petiole) numerous and warty, leafy structures around the petiole junction with the branch glandular ...... Salix lucida ssp. lasiandra

38’ Glands at leaf base junction with leaf stalk (petiole) not obvious, The leafy structures around the petiole attachment with the branch are not obviously glandular ...... Salix laevigata

7 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Betulaceae - Birch family DESCRIPTION

White alder- Alnus rhombifolia Nutt. These trees are monoecious. The trunk can reach heights of up to 25 meters. Bark is whitish or gray brown. Leaf blades are thick. Mature leaves are 5-11 cm in length. Upper leaf surfaces are green. Lower leaf surfaces are light yellow green and puberulent. The leaf midrib and major veins are not indented. The leaf apex is round to acute. Leaf bases are cordate to cuneate. The leaf margin is generally fl at. The margin may be fi nely or coarsely double serrate. Petioles are pubescent, and fl attened. The petiole is 1-2 cm long. Catkins are 5-20 cm in length. Male catkin bracts subtend three fl owers and four bractlets. There may be more than two catkins in a cluster. Staminate fl owers have four sepals, and 1-4 stamens. Female catkins have woody bracts subtending two fl owers and four bractlets. The woody bracts are thickened and slightly lobed at the apex. Nutlets are broadly ovate with thin narrow margins. Nutlets are woody and winged with many in the cone-like catkin.

Updated June 12, 2008 8 McBain and Trush, Inc. 2007

Oleaceae - Olive family DESCRIPTION

Oregon ash- Fraxinus latifolia Benth. Members of the Oleaceae are characterized by being dioecious trees. The trunk can reach heights of 25 meters. Twigs are cylindrical. Twigs are generally puberulent, becoming glaborous with age. Leaves are odd pinnately compound. There may be 5 to 7 leafl ets per leaf. Mature leafl ets range from 2-10 cm in size. The individual leafl et shape is widely elliptic to narrowly ovate. Lower leafl et surfaces are tomentose to glabrate underneath. The upper leafl et’s surface is pubescent. Leafl et tips are rounded to acute. Margins are entire but may be slightly to obviously serrate. Leafl ets are sessile or nearly so. The infl orescences are individual panicles with peduncles and individual fl owers borne on pedicels. The male fl ower has two stamens, a vestigial pistil and no petals. Female fl owers have no petals and two ovaries per chamber. The calyx is approximately 1mm. The mature ovary is a winged achene (samara). Achene bodies are terete with the wing being decurrent for more or less than ¾ of its length.

9 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Salicaceae - Willow family Members of the Salicaceae are dioecious. Populus fl owers are borne on pendant catkins 3 -8 cm in length. Populus catkins all have scale like bracts that are cut into narrow segments subtending each fl ower. Populus fl owers are typically sessile on a cup or saucer shaped disk. DESCRIPTION

Black cottonwood- Populus balsamifera ssp. trichocarpa (Torrey & A.Grey)Brayshaw. This tree was recently reclassifi ed from P. trichocarpa. There is not signifi cant difference between P. trichocarpa and P. balsamifera to warrant a specifi c epithet, however there is great enough variation to warrant subspecies status. Trees can reach heights of 30 meters, with wide spreading crowns. Winter buds are fi nely ciliate. When dormancy is broken the winter buds are fragrant and resinous. Twigs are brown when young turning gray with age. Leaves are 3-7 cm when mature. Leaf shapes are narrowly to widely ovate. Upper leaf surfaces are green, and lower surfaces are glaucous. Leaf tips are acute but can be tapered. Leaf bases range from round to cordate. Leaf margins are fi nely scalloped. The petiole is to ½ the blade length. Petioles are terete in cross section. The adaxial side of the petiole is round. The abaxial petiole surface is channeled with a pair of glands at the junction with the blade. Flowers have no true perianth. Each male fl ower bears 40-60 stamens. Female fl owers have ovoid, pubescent ovaries. Fruit is a dehiscent capsule comprised of 2-3 valves. Capsules are subglobose. 4mm thick and remain pubescent.

Updated June 12, 2008 10 McBain and Trush, Inc. 2007 DESCRIPTION

Fremont cottonwood- Populus Fremontii ssp. Fremontii Ser. Trees may reach 20 meters in height. Branches are large and spreading forming a broad open crown. Winter buds are resinous but not fragrant. Twigs are yellow becoming gray with age. Twigs may range from hairy to glaborous. Mature leaves are 3-7 cm in size. Leaf shape is strongly deltate. Upper and lower leaf surfaces are yellow green, glaborous, and often stained with milky resins. The leaf tips may or may not be tapered. The leaf base is slightly cordate to fl at. Margins are coarsely scalloped and may be serrate, through dentate. Petiole length is ½ to equal that of the blade length. Petioles are laterally compressed near insertion point with lamina. Male fl owers have 60 or more stamens. Anthers are dark red. Female fl owers ovaries are glaborous and born on pedicels approximately 3 mm long. The fruit is a three valved capsule 8-12 mm in size.

11 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River DESCRIPTION

Narrowleaf willow- Salix exigua Nutt. Recent taxonomic work indicates that Salix hindsiana is a highly variable variety of S. exigua. The more morphologically different forms of S. hindsiana may be derived from a cross of S. exigua and Salix sessifolia. S. exigua is now a complex of highly variable shrubs. S. exigua is a shrub smaller than 7 m. Plants are easily propagated by fragmentation of the roots. Twigs are densely silver and tomentose/pilose becoming glaborous. Mature leaves are 4-5 cm long and 3-10 mm wide. Leaf shape is linear to lance/linear tapering at both ends. Leaf tips and bases are acuminate. Young leaves are silky-villous or sub tomentose, sometimes becoming glabrate. Leaf margins are entire to sharply serrate. Petioles are very short to sessile. Stipules are wanting. Catkins appear with or after leaves on long leafy peduncles. Catkins are sometimes branched and can reach 22-70 mm in size. The fl ower bracts are tawny. Male fl owers have two stamens and pubescent fi laments. Female fl owers have divided stigmas that are deciduous after fl owering. Styles are 0.5mm if present at all. The ovary is glaborous. The capsule is subsessile, 5-6mm long. Mature capsules are villous to tomentose, and narrowly lanceolate.

Updated June 12, 2008 12 McBain and Trush, Inc. 2007 DESCRIPTION

Arroyo willow- Salix lasiolepis Benth. Plants are shrubs or small trees less than 10m. Twigs are yellowish to dark brown. Twigs are tomentose, or velvety becoming glaborous with age. Twigs are generally brittle at the base. Mature leaves are 35-125 mm in length. The leaf shape is more or less narrowly elliptic to oblanceolate. Young leaf surfaces are hairy. Leaf tips are acute. The leaf base is wedge shaped. Margins are generally entire but can be irregularly serrate. The margin may be revolute. Catkins appear before leaves. Catkins are sessile and reach 15-70mm in size at maturity. Flower bracts are dark brown and may or may not have densely pilose/tomentose hairs. Male fl owers have two stamens. The stamen fi laments are united near the insertion with receptacle. Female fl owers are borne on a pedicel 0.5-2.4 mm long. The ovary is glaborous. The style is 0.1-0.6 mm in length. Mature capsules are 4-5.5mm in size.

13 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River DESCRIPTION

Dusky willow- Salix melanopsis Nutt. Plants are easily propagated by root sprouts. These plants are shrubs no larger than 4 m. Branches are more divaricatly branched than other willow species. Twigs are brown to blackish and are often lustrous. Young leaf surfaces are silky. Mature leaves are 30-85 mm long and 6-15 mm wide. Leaves are oblanceolate to narrowly elliptic shaped. The upper surface of the leaf is dark green and glaborous. Lower leaf surfaces are paler to glaucescent, typically sub-glaborous. The leaf tip and base is acute. Leaf margins are entire to sparsely spiny serrate, sometimes the margins are spinulose/denticulate to closely denticulate. Petioles are subsessile to short. Stipule shape, if stipules are present, is lanceolate to semicordate, dentate. The catkins appear with or after leaves. The catkins are slender and sometimes branched. Catkin length is 4-70mm and are often borne on leafy shoots. Flower bracts are tawny or light brown. Scales are oblong to ovate, becoming erose at the apex. Scale surfaces are nearly or quite glaborous. Male fl owers have two stamens with the fi laments being distinctly hairy. The female fl ower styles are obsolete and stigmas are extremely short. The ovary is glaborous and subsessile. Ovary surfaces are glaborous but rarely they are sparsely pilose. Pistillate scales are often plainly striate with 3-5 nerves. The mature capsule is 4-5 mm long and ovate/lanceolate in shape.

Updated June 12, 2008 14 McBain and Trush, Inc. 2007 DESCRIPTION

Shiny willow- Salix lucida ssp. lasiandra (Benth)E. Murray. Field identifi cation of this willow is easy because of the glands. This plant can grow as tree or shrub less than 10 m. Bark is rough and brown. Twigs are deep lustrous yellow, glaborous. Immature leaves can be glaborous, white, white/hairy, or rusty hairy. Mature leaf blades are 53-170 mm long. The leaf shape is lanceolate to broadly lanceolate, sometimes oblanceolate. The upper leaf surface is shiny dark green, while the underside is glaucous. The leaf tip is acuminate. The leaf base is acute to rounded, closely glandular, crenate/serrulate. The leaf margins are fi nely serrate. Stipules are large, often persistent, rounded, glandular, and acute. The petioles are stout, glandular above and near base of leaf lamina. The stipule characteristics and the abundance of glands are very good identifi cation features for fully leafed out plants. Catkins appear with the leaves. Catkins are pendunculate and range 20-90 mm in length. Catkin scales are yellow to tawny, and are lanceolate to ovate in shape. Each male fl ower has 3-5 stamens. In the staminate fl ower, the fi lament’s basal portion is pubescent. The female fl ower has a very short style. The ovary is glaborous, and borne on a .8 to 2mm pedicel. The capsule is glabrous, 5-7mm long and pale straw to light brown colored. The fl oral scale is deciduous in the female catkin after fertilization.

15 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River DESCRIPTION

Red willow- Salix laevigata Bebb. Field identifi cation of this willow is often diffi cult. The defi ning characteristic of S. laevigata is bud scales that are not fused (i.e. free) and is not abundantly glandular, however some glands are often present near the insertion of the petiole. S. laevigata is frequently misidentifi ed as S. lucida ssp. lasiandra . This plant can grow as tree or shrub less than 10 m. Bark is rough and brown. Twigs are glaborous, deep blood red, and sometime glaucous. Immature leaves can be glaborous, white, white/hairy, or rusty hairy. Mature leaf blades are 53-170 mm long. The leaf shape is lanceolate to broadly lanceolate, sometimes oblanceolate. The upper leaf surface is shiny dark green, while the underside is glaucous. The leaf tip is acuminate. The leaf base is acute to rounded, and frequently glandular, crenate/serrulate. The leaf margins are fi nely serrate. Stipules are small or vestigial, deciduous, rounded, glandular, and acute. The petioles are thin, glandular above and near base of leaf lamina. The stipule characteristic is very good for fully leafed out plants. Catkins appear with the leaves. Catkins are pendunculate and range 20-90 mm in length. Catkin scales are yellow to tawny, and are lanceolate to ovate in shape. Each male fl ower has 3-5 stamens. In the staminate fl ower, the fi lament’s basal portion is pubescent. The female fl ower has a very short style. The ovary is glaborous, and borne on a .8 to 2 mm pedicel. The capsule is glabrous, 5-7 mm long and pale straw to light brown colored. The fl oral scale is deciduous in the female catkin after fertilization.

Updated June 12, 2008 16 McBain and Trush, Inc. 2007 DESCRIPTION

Sitka willow – Salix sitchensis Bong. Plants are shrubs or small trees less than 10m. Twigs are brownish and silky but may become glabrous with age. Twigs are generally fl exible and may or may not be brittle at the base. Mature leaves are 52 - 110 mm in length. The leaf shape is more or less lanceolate to widely obovate. The leaf underside is velvety (silky wooly) but not glaucous. Leaf tips are acute or pointed. The leaf base is wedge shaped. Margins are entire to fi nely serrate. The margin may be strongly rolled (revolute) over near the base of the leaf blade. Catkins appear before just before or with leaves. Catkins are on leafy shoots generally 3-200 mm long and reach 26 - 95 mm at maturity. Flower bracts are tawny or brown typically have densely pilose/tomentose hairs. Male fl owers have one stamen. Female fl owers are borne on a pedicel 0.4-1.2 mm long. The ovary is hairy. The style is 0.4 - 0.8 mm in length. Mature capsules are 4 - 5.5 mm in size. Uncommon along the Trinity River Mainstem above the confl uence of the south fork of the Trinity

17 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Simaroubaceae- Simarouba or Quassia family Members of the Simaroubaceae are dioecious and native to China. DESCRIPTION

Tree of heaven- Ailanthus altissima (Miller) Swingle Mature plants are deciduous trees greater than < 20 m. Leaves are compound with 13 – 25 leafl ets (once pinnate with an odd number of leafl ets) and alternate on branches. Mature leaves are foul smelling when crushed. Leaf surfaces are hairless (glabrous). Leaf margins have 2 - 4 teeth each with large gland on the underside of each leafl et. 10-15 male fl owers are inserted on a cuplike disk. 2-5 female fl owers are borne at the shoot tips. The mature ovary is a winged achene (samara). This exotic plant is invasive and common in dry disturbed sites

Updated June 12, 2008 18 McBain and Trush, Inc. 2007

Juglandaceae- Walnut family Members of the Juglandaceae are monecious. Male fl owers are pendant catkins borne on last years branches. Female fl owers 1-3 at tip of new twigs. DESCRIPTION

Black walnut- Juglans californica S. Watson var. hindsii Jepson Mature plants are deciduous trees greater than 5 m. Leaves are compound with 11 – 19 leafl et (once pinnate with an odd number of leafl ets) and alternate on branches. Generally without leafy stipules at the leaf stalk base. Leaf surfaces are hairless (glabrous). Leaf tips are acute. Numerous male fl owers are borne in pendant catkins growing from axillary buds. Few female fl owers are borne at the shoot tips. The sepals are fused around a woody shell (i.e., the walnut), becoming strong smelling as the fruit matures. Uncommon along the Trinity River Mainstem.

19 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Fabaceae- Pea family Members of the Fabaceae typically have perfect fl owers borne in racemes. DESCRIPTION

Black locust- Robinia pseudoacacia L. Mature plants are deciduous trees greater than 5 m. Leaves are compound (once pinnate with an odd number of leafl ets) and alternate on branches. Leafy stipules at the leaf stalk base become sharp spines (thorns) Leaf surfaces are hairless (glabrous). Leaf tips are acute. Infl orescences are pendant racemes growing from axillary buds. Flowers are typical for the pea family, though the sepals are bell shaped with 5 lobes, The 5 petals are generally white and the banner refl exed. Nine stamen fi laments are fused and one is free. The fruit resembles a large black woody pea pod. This exotic plant is potentially invasive.

Updated June 12, 2008 20 McBain and Trush, Inc. 2007

GLOSSARY GLOSSARY

21 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Acute- the angle between two leaf margin where they meet at the base of the leaf blade is less than 90

Achene- A small, dry, indehiscent fruit with a single chamber and a single seed (ovule), and with the seed attached to the ovary wall at a single point. For example the sunfl ower seed in the shell is an achene.

Acuminate- a leaf tip that draws into a long tapering point picture

Axillary buds- the locations where branch shoots develop and grow; between the leaf stalk and the woody branch (see also winter buds, compound leaf, simple leaf) GLOSSARY

Bud scale- A modifi ed scale-like leaf covering a bud (see also fused and multiple bud scales

Catkins- An infl orescence consisting of a dense spike or raceme of fl owers lacking petals (i.e., lacking petals); an ament.

Updated June 12, 2008 22 McBain and Trush, Inc. 2007

Capsule- A dry, dehiscent fruit composed of more than one carpel

Ciliate- With a marginal fringe of hairs Drawing

Cup shaped disk- An enlargement or outgrowth of the receptacle around the base of the ovary or fruit

Compound leaf- A leaf separated into two or more distinct leafl ets GLOSSARY

Densely hairy- A leaf surface with dense, long hairs (see also densely hairy, wooly hairy and velevety)

Dioecious- Flowers imperfect, the male (staminate) and female (pistillate) fl owers borne on different plants

23 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Deciduous- Falling off, as leaves from a tree; not evergreen; not persistent

Elliptic- A leaf resembling a football, 2-3x longer than wide, whose broadest axis is in the middle of the leaf blade

Female fl owers- Flowers whose only functional reproductive organs are pistils (i.e., stigma, style and ovary)

Flower bract- A reduced leaf or leaf like structure at the base of a fl ower or infl orescence GLOSSARY

Free bud scale- A modifi ed scale-like leaf whose edges are not attached covering an axillary bud

Fused bud scales- A modifi ed scale-like leaf covering a bud whose edges are attached

Updated June 12, 2008 24 McBain and Trush, Inc. 2007

Glabrous- Refers to smooth or hairless leaf or ovary surfaces

Glandular- Of or pertaining to a gland; gland-like; bearing glands

Glaucous- Covered with a whitish or bluish waxy coating (bloom), as on the surface of a plum

Hairy ovary- A part in of female fl ower (pistil) where seed(s) develop GLOSSARY

Lanceolate- A leaf much longer than wide, whose broadest axis is below the middle of the leaf blade

Leaf blade- The broad part of a leaf

25 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Leaf margin- A leaf with the edge, as in the edge of a leaf blade

Leafy shoot- A young stem or branch

Leaf stalk- The supporting structure of a leaf (petiole)

Linear- A leaf resembling a line; long and narrow with more or less parallel sides GLOSSARY

Male fl owers- Flowers whose only functional reproductive organs are stamens (i.e., fi lament and anthers)

Monoecious- Flowers imperfect, the male (staminate) and female (pistillate) fl owers borne on the same plant (compare dioecious)

Updated June 12, 2008 26 McBain and Trush, Inc. 2007

Multiple unfused bud scales- A series of modifi ed scale-like leaves covering a bud whose edges are not attached

Narrowly obovate- A whose broadest axis is above the middle of the leaf blade near the tip

Narrowly elliptic- A leaf many times longer than wide, whose broadest axis is in the middle of the leaf blade

Obolanceolate- A leaf resembling a spoon, whose broadest axis is above the middle of the leaf blade near the tip GLOSSARY

ovary Ovary- The expanded basal portion of the female fl ower (pistil) that contains and surrounds the ovules which become seeds after pollination

ovules

Ovules- The plant equivalent of an “egg”; ovules become seeds after contact with pollen (i.e., pollination)

ovules

27 Updated June 12, 2008 Field Guide to the Common Riparian Trees and Shrubs of the Lower Trinity River

Pea Family fl ower- A fl ower with fuses sepals (calyx) and 5 petals. One petal forms a “banner”, two form a “keel”, and two petals form “wings”

Pendulous- plant parts (typically catkins) that hang rather than being supported

Perfect fl owers- A fl ower the both male and female reproductive organs, (stamens and pistils) and petals and sepals; bisexual Petiole- A leaf stalk

Pistil- The female part of a fl ower (i.e., stigma, style and ovary) GLOSSARY

Pseudo cone- A woody female catkin in the genus Alnus resembling a pine cone picture of ALRH cones

Samara- A dry, indehiscent , winged fruit (see also winged achene)

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Silky hairy- A leaf surface moderately covered with long fi ne hairs

Silky woolly- a leaf surface densely covered with short fi ne silky hairs (see also velvety)

Simple leaf- A leaf undivided, as a leaf blade which is not separated into leafl ets (though the blade may be deeply lobed or cleft).

Sparsely hairy- A leaf surface covered with few long fi ne hairs GLOSSARY

Stamens- The male reproductive organ of a fl ower, consisting on an anther and fi lament

Stipules- Leaf or scale like structures where the leaf stalk meets the growing shoot/branch

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Terminal leafl et- A leafl et at the tip of or apex

Tomentose- A leaf surface with dense, matted, generally interwoven hairs (see also densely hairy, wooly hairy and velevety)

Warty- small bumps (glands) or sometimes leafy glandular material where the leaf blade meets the leaf stalk

Winter buds- A hibernating vegetative shoot (see also axillary buds, compound leaf simple leaf) GLOSSARY

Winged achene- A dry, indehiscent , winged fruit (see also samara)

wing Winged nutlet- A small nut; one of the lobes or sections of the mature ovary possessing wings nutlet

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Velvety- a leaf surface densely covered with short fi ne silky hairs (see also silky wooly) GLOSSARY

31 Updated June 12, 2008