Dendrology, Tree Identification Techniques, & Important Blackland Prairie Trees Chris Ebling Texas Master Naturalist © Christopher Ebling 2008-2019. All rights reserved. Any redistribution or reproduction of part or all of the contents in any form is prohibited. You may, with express written permission of the author, reproduce, extract portions of, and/or reuse the content for educational purposes only, provided that you credit the author as the source of the material. 1 © Christopher Ebling 2008-2019 All rights reserved. Tools to Aide in Identification ◼ Identification books and field guides ◼ Web sites ◼ Mobile applications ◼ Botanical descriptions are often highly technical TWIGS and BUDS: pubescent light brown twigs with corky wings or ridges; ovoid light brown to gray buds, smooth 1⁄4 inch (6 mm) long. LEAVES: alternate; simple; petiole 5⁄8 - 1 inch (16 - 25 mm) in length; leaf blade is obovate to narrowly elliptical in outline, 2 3⁄4 - 6 inches (70 - 152 mm) long, 2 - 5 inches (51 - 127 mm) wide, 5 - 7 lobed with center sinuses nearly reaching midrib, base rounded to cuneate, rounded apex; dark green above, grayish-green with finely dense pubescence below. The Purpose of This Talk is to Explain These Terms 2 © Christopher Ebling, 2008-2011. All rights reserved. Tools of the Trade 3 © Christopher Ebling, 2008-2011. All rights reserved. What is a Tree? ◼ A “woody plant” is a plant with persistent woody parts that do not die back in adverse conditions ❑ Wood = Cellulose structures on a Lignin framework. ❑ Most woody plants are trees or shrubs. ◼ A tree is a woody plant with a single erect perennial trunk at least 3 inches in diameter at breast height (DBH). ◼ Most trees have definitely formed crowns of foliage and attains heights in excess of 13 feet. Source: US Forest Service All trees are woody plants, but not all woody plants are trees. 4 © Christopher Ebling, 2008-2011. All rights reserved. All trees are woody plants, but are all woody plants trees? 5 © Christopher Ebling, 2008-2011. All rights reserved. Tree or Not a Tree? 6 © Christopher Ebling, 2008-2011. All rights reserved. Tree or Not a Tree? 7 © Christopher Ebling, 2008-2011. All rights reserved. Tree or Not a Tree? 8 © Christopher Ebling, 2008-2011. All rights reserved. Trunk Cross Section ◼ Bark ❑ The outer protective covering of tree trunks. ❑ Most of the total thickness of bark consists of outer bark, which is made up of dead cells. ❑ Outer bark may be very thick, as in the cork oak, or quite thin, as in young birches and maples. ❑ Openings in the outer bar (lenticels) allow the movement of carbon dioxide Source: Microsoft Encarta and oxygen to and from the inner tissues. ◼ Phloem (sapwood) ❑ A thin layer of living cells that act together to transport food in the form of sugars, which are made in the tree’s leaves, through the trunk and stems to other parts of the tree. ❑ As old layers of outer bark are sloughed off, new ones are constantly being added from the inside, where new phloem is always being created.. 9 © Christopher Ebling, 2008-2011. All rights reserved. Trunk Cross Section ◼ Cambium ❑ Separates the living xylem cells from the phloem. ❑ As the tree grows and develops, the cambium forms new phloem and xylem cells. ❑ The layers of xylem cells form rings; these rings can be counted to determine the age of the tree in areas with distinct growing seasons ◼ Xylem (Sapwood - heartwood) Source: Microsoft Encarta ❑ Consists almost entirely of dead cells. ❑ The living xylem cells, however, act as the tree’s plumbing system by transporting water and dissolved food through the trunk and stems. ◼ Pith ❑ Serves as a storage tissue for sugars and as a reservoir for wastes in young trees. ❑ In older trees the pith is crushed by the xylem’s woody tissue, and wastes are simply deposited in the wood cells near the center of the trunk. 10 © Christopher Ebling, 2008-2011. All rights reserved. Tree Classes White Pine ◼ Angiosperms Bur Oak ❑ A plant whose seeds are enclosed in an ovary. ❑ “Deciduous”, “hardwood” ◼ Gymnosperms ❑ Literally means “naked seed” ❑ A plant whose seeds are not enclosed in an ovary. ❑ “Conifer”, “evergreen”, “softwood” ❑ Other minor tree families ◼ Ginko, Cycad, etc. ◼ Beware! ❑ Not all Angiosperms are deciduous ◼ Live Oak ❑ Not all Gymnosperms are evergreen ◼ Bald Cyprus, Larch 11 © Christopher Ebling, 2008-2011. All rights reserved. How do we identify trees? ◼ Location ◼ Fruit ◼ Form ◼ Wood ◼ Leaves ◼ Bark ◼ Twigs ◼ Flowers Tree identification is a “holistic” activity, often involving multiple identifying characteristics which will vary by time of year. 12 © Christopher Ebling, 2008-2011. All rights reserved. Location ◼ Trees are highly adapted to their environment ❑ Temperature range ❑ Total rainfall and annual distribution ❑ Soil type and chemistry ◼ Understanding the local environment can help you narrow the range of choices ◼ For example, in a natural environment: ❑ Will you ever see a long-leaf pine on the Blackland Prairie? ❑ Will you ever see a Bur Oak in the Trans-Pecos? ◼ Beware! Altitude can mimic colder, wetter climate conditions! ❑ Guadalupe National Park ◼ Relic forest of Douglas Fir, Ponderosa Pine, SW White Pine, & Aspen forest surrounded by desert ◼ Maintains climatic conditions from 15,000 years ago. 13 © Christopher Ebling, 2008-2011. All rights reserved. Form Longleaf Pine ◼ Different tree families and species take on distinct forms and exhibit typical American Elm silhouettes in a natural setting. ◼ Like location, the form of a tree can be used to narrow the list of possible choices. ◼ Beware! ❑ Forms can vary widely in response to local conditions! ◼ Location i.e. edge of range, altitude ◼ Tree density ◼ Microclimate 14 © Christopher Ebling, 2008-2011. All rights reserved. Leaf Characteristics ◼ Leaf characteristics are a very good indicator of tree type. ◼ Leaves are described by their: ❑ Arrangement on twig ❑ Overall shape ❑ Complexity ◼ Simple, pinnate, bi-pinnate ❑ Margins ❑ Apices ❑ Bases ❑ Venation pattern ❑ Surface features ❑ Petioles ◼ Shape ◼ Presence of stipules ◼ Problem – leaves only available during the growing season on deciduous trees ◼ Beware! ❑ Leaf shapes can vary widely from tree to tree and even on a single tree (i.e. top to bottom) ❑ Why? 15 © Christopher Ebling, 2008-2011. All rights reserved. Leaf Arrangement ◼ A preliminary indicator on dormant twigs. ◼ Alternate ❑ Leaves not paired on twig ❑ Eg. Elm ◼ Opposite ❑ Leaves paired on twig ❑ Eg. Ash ◼ Whorled ❑ Leaves arranged in a whorl on twig ❑ Eg. Catalpa ◼ Are leaves arranged in ranks along a branch? ❑ What is the most ubiquitous form in the universe? 16 © Christopher Ebling, 2008-2011. All rights reserved. An Interesting Digression… ◼ All plants, including trees, spiral as they grow ❑ Why? ◼ The number of leaves in a given spiral sequence is a Fibonacci number. ❑ 0,1,1,2,3,5,8,13,21… ◼ The ratio of leaves in the spiral to the number of turns in the spiral is a sequence of Fibonacci numbers! © Jill Britton, 2005 17 © Christopher Ebling, 2008-2011. All rights reserved. Deciduous Leaf Characteristics Source: Wikipedia 18 © Christopher Ebling, 2008-2011. All rights reserved. Coniferous Leaf Characteristics New Growth Mature ◼ Short, blunt, curved and needle-shaped leaf ❑ Juniperus ❑ Picea ❑ Abies ◼ Bundles of long needle- shaped leaves ❑ Pinus ◼ Flattened, overlapped and scale-like leaves ❑ Thuja Chris Evans, River to River CWMA, Bugwood.org 19 © Christopher Ebling, 2008-2011. All rights reserved. Twig Characteristics ◼ Key features (see notes) ❑ Terminal bud ❑ Axial bud ❑ Leaf scar ❑ Bundle scar ❑ Stipule scar ❑ Lenticels ❑ Pith Source: US Forest Service 20 © Christopher Ebling, 2008-2011. All rights reserved. Fruit Characteristics Pine Seed ◼ Cone ❑ An organ on conifers that contains the reproductive Pine structures Male Cones ❑ Male ◼ Pollen bearing ◼ Similar across species ❑ Female Bald Cypress Yew ◼ Seed bearing Red Cedar ◼ vary widely across species ◼ Excellent for identification purposes 21 © Christopher Ebling, 2008-2011. All rights reserved. Female Pine Cones – A Closer Look ◼ Two general types ❑ Haploxylon – white pines ◼ Umbo generally unarmed ❑ Diploxylon – yellow pines ◼ Umbo generally armed ◼ Three major parts ❑ Peduncle/rachis ❑ Seed scale/umbo ❑ Seed ◼ Vary in size from 1.5” to 28” ◼ See notes page for more detail 22 © Christopher Ebling, 2008-2011. All rights reserved. Fruit Characteristics Pecan ◼ Nut ❑ A dry, one seeded fruit with a thickened and hardened wall. ◼ Oak, walnut, hickory, pecan Hickory Pin Oak Bur Oak Black Walnut 23 © Christopher Ebling, 2008-2011. All rights reserved. Fruit Characteristics Green Ash ◼ Samara ❑ A one- or two-seeded dry fruit in which part of the fruit wall grows out into a wing. ◼ Elm, maple, ash. American Elm Red Maple 24 © Christopher Ebling, 2008-2011. All rights reserved. Fruit Characteristics Choke Cherry Poison Ivy ◼ Drupe ❑ A one-seeded simple fruit in which the innermost part is hard and stony, the outermost part is a relatively thin skin, and the Dogwood middle part between the skin and the stone becomes either fleshy or fibrous. ◼ Choke cherry, Poison Ivy, Dogwood 25 © Christopher Ebling, 2008-2011. All rights reserved. Fruit Characteristics Persimmon ◼ Berry ❑ A simple fruit in which the ovary wall or at least its inner portions become enlarged and usually juicy. ◼ Persimmon 26 © Christopher Ebling, 2008-2011. All rights reserved. Fruit Characteristics Apple ◼ Pome ❑ A fruit with fleshy outer tissue and a papery- walled inner chamber containing the seeds. Pear ◼ Apple, Pear 27 © Christopher