Tree Identification. Todd P. West, Ph.D. North Dakota State University

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1 Tree Identification Todd P. West, Ph.D. North Dakota State University

2 ISA Arborists Certification Study Guide Chapter 2 TREE IDENTIFICATION

3 Objectives 1. Describe how all plants are classified and how scientific manes are based on the classification system. 2. Explain what a scientific name is, why scientific names are used and how they are written. 3. Explain how plant characteristics such as growth habit, texture and color can be used in tree identification. 4. Describe how leaf arrangement and morphology are used to help identify trees. 5. Compare various leaf shapes and types of leaf margins, bases and apices. 6. Identify trees without leaves by using bud and twig characteristics.

4 Why is tree identification important? First step before prescribing tree care. Plant species identification is a requirement in order to apply pesticides legally. Species: a taxonomic group of organisms composed of individuals of the same genus that can reproduce among themselves and have similar offspring. Knowing the different species and how they naturally respond at different times of the year give insights on care of the given species.

5 Identification Assists in Proper Tree Care Disease, pests and cultural requirements vary among species, arborists should be able to identify a tree before attempting a diagnosis or treatment recommendations. When should I prune? What pests (disease and insects) do I need to be concerned with? How strong is the wood? Liabilities? When does it leaf out? Will it drop its leaves? What is normal for this tree? Identification helps with proper tree selection as well.

6 Plant Classification Deciduous - A plant that loses its leaves annually at the end of its growing season. Evergreen - A plant which has foliage throughout the year. An evergreen plant does drop its older leaves each year, though this often occurs over a long period of time and at any season. Foliage may be: needles, scales, or broad leaves.

7 Woody plants may be classified as: Tree woody plant that usually has a dominant vertical trunk and reaches heights of 15 or more. Shrub woody plant that is usually smaller than a tree and generally has multiple branches originating at or near the ground. Vine woody plant with flexible stems and may be classified by growth habit as either: Climbing require support (a trellis or wall for example). Tendrils may be produced which aid in attachment to structures. Ground cover similar to climbers with the exception of a prostrate growing habit.

8 Woody plants may be classified as: Angiosperm Plants having seeds borne within a pericarp (fruit) Gymnosperm Plants that are cone bearing or have naked seed often displaying different leaf types than those associated with angiosperms.

9 Plant Nomenclature Scientific naming system for living organisms; scientific names are (sometimes in) Latin and written in italics, the genus is followed by the specific epithet. Each plant has a unique scientific name that is the same throughout the world. Scientific names are based on a species classification system binomial nomenclature. Two parts

10 Binomial Nomenclature Carolus Linnaeus Developed the current Latin-based system Classification based on the number of sexual parts. Two Latin names to identify species = genus + specific epithet. International Code of Botanical Nomenclature (ICBN) provides guidelines for standardizing plant naming and rules are revised as new scientific evidence becomes available.

11 Classifications Family An assemblage of genera (can be a single genus) that rather closely or uniformly resemble each other in general appearance and technical characters. Always ends in aceae. Genus A more or less closely related and definable group of plants comprising one or more species. Always underlined or italicized. Specific Epithet A group of individuals that adhere to the essential identification characteristics but display variation so as not to be categorized as replicas of one another. Always underlined or italicized.

12 Classifications Variety, Subspecies and Forma Subdivision of a species having a distinct difference and breeding true to that difference. Variety is abbreviated var.; the plural is varieties. Gleditsia triacanthos Common Honeylocust Gleditsia triacanthos var. inermis Thornless Common Honeylocust Subspecies is abbreviated subsp. or spp.; the plural is subspecies. Syringa reticulata Japanese Tree Lilac Syringa reticulata ssp. pekinensis Pekin Lilac Syringa pekinensis Pekin Lilac Forma is similar to spp. but less obvious differences. Cornus florida f. rubra Red Flowering Dogwood.

13 Classifications Hybrid Results of crossbreeding between two different species, usually from the same genus. Hybrid names are written with an x between the genus and specific epithet. x should not be underlined or italicized. Example: Acer x freemanii JeffersRed Autumn Blaze Maple

14 Classifications - Cultivar Horticulturally the most important unit of classification An assemblage of cultivated plants which is clearly distinguished by any characters and which when reproduced (sexually or asexually) retains its distinguishing characteristic(s) Most woody plant cultivars are considered to be clones Cone: asexually produced organisms that are genetically identical. Exceptions: Acer saccharum 'Jefselk Lord Selkirk Sugar Maple (Seed Strain) Cultivar names are never underlined or italicized, they are put into single quotation marks.

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17 Example of Scientific Classification Example of Scientific Classification of Plants Taxon Example Common Name Kingdom Plantae Plant Division Magnoliophyta (angiosperm) Flowering Plant Class Eudicots Dicot Order Sapindales Family Sapindaceae (Aceraceae) Soapberry Family Genus Acer Maple Specific Epithet Acer saccharinum L. Silver Maple Cultivar Acer saccharinum Skinner Skinner s Silver Maple Species = Genus + Specific Epithet (Binomial Nomenclature)

18 Silver Maple Skinner s Silver Maple

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20 Common Names

21 Common Names

22 Common Names Ironwood Ostrya virginiana, American Hophornbeam

23 Ostrya virginiana, American Hophornbeam

24 Choricarpia subargentea, Giant ironwood Native to Australian rainforest

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26 Classifications Trademark Plant nomenclature of cultivated plants is further complicated by the use of trademark and patented cultivar names. River Birch Betula nigra Heritage River Birch Betula nigra Cully Betula nigra Heritage is incorrect Acer x freemanii JeffersRed Autumn Blaze Maple Autumn Blaze is incorrect

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28 Basic ID Principles Many trees can be identified at a distance. American Elm (Ulmus americana) - Vase-shaped growth habit with overarching limbs Still need to verify identification before any care can be performed. Woody plant ID is based on morphology Size, shape and appearance of plant parts. Fundamental knowledge of woody plant anatomy is essential. Classification is based on reproductive structures (flower and fruit). Identification by arborists is often based on other anatomical features such as form, bark, twigs, leaves, buds, leaves, scent as well as flowers and fruit. It is essential to be able to identify trees by multiple features to not limit identification based on seasonal cues such as just leaves.

29 First Step in Tree ID Determining type of leaf. Gymnosperms often evergreen Angiosperms often deciduous Juniper Arborvitae Juniper Simple Compound Pine Spruce Fir Yew

30 Compound Leaves

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39 Bud (Leaf) Arrangement on Stem Maple (Acer) Buckeye (Aesculus) Dogwood (Most)(Cornus) Ash (Fraxinus) Corktree (Phellodendron) MAD Horse maple, ash, dogwood and horsechestnut Birch (Betula) Hackberry (Celtis) Pagoda Dogwood (Cornus) Honeylocust (Gleditsia) Oak (Quercus) Elm (Ulmus) Catalpa (Catalpa) Figure 2.8

40 Leaf Shapes entire serrate dentate crenate serrulate double serrate undulate lobed

41 Leaf Bases and Apices

42 What are they?

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44 Prairie Vision Asian White Birch - Betula platyphylla Verdale leaf base acute to more truncate Prairie Dream Paper Birch Betula papyrifera Varen leaf base acute to more rounded

45 Prairie Vision Asian White Birch - Betula platyphylla Verdale leaf base acute to more truncate Prairie Dream Paper Birch Betula papyrifera Varen leaf base acute to more rounded

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47 Is it a Pine, a Spruce or a Fir? White Fir Abies concolor

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49 Key to Pinus spp. (Pines) 1a. Needles in 2 s..2 2a. Needles 3 or less long...5 5a. Current year stems reddish purple with light colored bloom (glaucous) Pinus virginiana (Virginia Pine), **cold hardy to zone 5 not hardy** 5b. Current year stems not purple, not glaucous a. Sharp pointed bluish green needles with 360 degree twist; bark of upper branches and trunk orange; usually a tree with single trunk; grey brown cones 3 long.pinus sylvestris (Scotch Pine) 6b. Bright green needles with slight curve, bark not orange; often compact, bushy and multistemmed; dark grey ovoid cones 2 long with dark ring around tip..pinus mugo (Mugo Pine) 2b. Needles greater than 3 long 7 7a. Young stems green with whitish bloom (glaucous); buds pubescent and not resinous; bark reddish to orange on upper branches and trunk....pinus densiflora (Japanese Red Pine), **cold hardy to zone 4 not hardy here** 7b. Young stems not glaucous; bark of upper trunk and branches not orange.8 8a. Buds not resinous, needles less than 5 long..pinus thunbergii (Japanese Black Pine), **cold hardy to zone 5 not hardy** 8b. Buds resinous, needles greater than 5 long...9 9a. Needles stiff and ending in horny point, dull, do not break when bent, 3.5 cones.....pinus nigra (Austrian Pine) 9b. Needles sharp pointed and shiny, snap when bent..pinus resinosa (Red Pine) 1b. Needles in 3 s (Mostly).3 3a. Needles less than 5 long Bark exfoliating creating irregular brownish to whitish patches, waxy (plastic-looking) medium green needles 2-4 long with raised midrib and serrated margins, 2-3 long cone Pinus bungeana (Lacebark Pine) 3b. Needles greater than 5 long Yellowish brown twigs, minute serrated and sharply pointed needles 8-10 long, oblong reddish brown bud with appressed resinous scales, vanilla scent to stems when bruised, 4 long cone....pinus ponderosa

50 1c. Needles in 5 s 4a. Needles less than 2 long..pinus aristata (Bristlecone Pine), **cold hardy to zone 4, doesn t do well as a result of elevation change** 4b. Needles greater than 2 long 10a. Needle edges smooth to touch, long and slightly twisted or curved; young stems shiny green and extremely flexible (according to Dirr, can be tied in knots not reliable id feature), 6 long cones..pinus flexilis (Limber Pine) 10b. Needle edges minutely toothed a. Leaves soft and flexible, 4 long with 2 stomatal lines on underside; stems with tufts of short hairs subtending needle clusters; 8 long cone.....pinus strobus (White Pine) 11b. Needle rather stiff, stem pubescence not as above a. Dense pubescence on 1 yr stems, orange-brown; 3 or longer light green twisting needles with stomatal lines on underside; 3 cones..pinus cembra (Swiss Stone Pine) 12b. Sparse pubescence to glabrous; needles long and twisted; 4 long cones....pinus parviflora (Japanese White Pine)

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53 The Maples Acer The maples have opposite, simple, palmately compound leaves; or more rarely leaves which are pinnately compound. The flowers are variable, usually non-ornamental and are primarily pollinated by insets. The flowers of Red and Silver Maples occur in lateral clusters; developing in the early spring, before leaves appear, from buds which were on the twigs throughout the winter. Other maples appear either with the leaves or after the leaves are fully developed; both often developing from the same buds. The fruits are very characteristic: consisting of a pair of wings with the seed enclosed in the base. They are often referred as samaras (single seed) but are more correctly called schizocarp (two seeds). Wind is the principle agency for seed dispersal. The buds are quite variable and are important means for identification. The leaf-scars are crescent-shaped or V-shaped with 3 conspicuous bundle-scars.