American sycamore. Platanus occidentalis. Secondary Name(s): American planetree, buttonwood. Leaf type: deciduous. Texas
Tree Identification 101 Pete Smith Texas Big Tree Registry Coordinator Texas Forest Service College Station, TX
[email protected] 979‐458‐6650
Tree Identification 101 What is a tree? Elbert Little, Jr. (1979): “a woody plant having one erect perennial stem or trunk at least three inches in diameter at breast height, a more or less definitely formed crown of foliage, and a height of at least 13 feet.” Benny Simpson (1988): “having a single trunk or multiple trunks, growing to 12 feet or more in height, and being definitely woody.” Merriam‐Webster Online: “a woody perennial plant having a single usually elongate main stem generally with few or no branches on its lower part.”
Tree Identification 101 Why are trees important to us? Long‐lived: • African baobab may reach 6,000 years • Bristlecone pine rings show 4,844 years Impressive size: • Tallest living thing (379 feet) is a coast redwood • ‘General Sherman’ giant sequoia has trunk volume of over 52,000 ft.3 Useful: • Fuel, shelter, agriculture,…, art, culture
Tree Identification 101 How many are there? Worldwide: as many as 100,000, which may represent up to 25% of all plants United States: • 826 species recognized by American Forests’ National Register of Big Trees (2008) • USDA’s Checklist of U.S. Trees (1979) includes 679 native and 69 naturalized species (748) Texas: 319 species recognized in Texas Big Tree Registry
Tree Identification 101 How do we tell them apart? Morphology: the form, structure and configuration of an organism Geography: the natural range of a species Genetics: new information on ‘relatedness’ of organisms
Plant Taxonomy: a branch of science that describes, classifies, and names plants.
Plant Classification Kingdom Phylum (or Division) Class Order Family Genus species Mnemonic device: King Phillip came over from greater Spain
Plant Classification Binomial System of Nomenclature “live oak” = Quercus virginiana or Quercus virginiana
Plant Classification • Gymnosperms – conifers • Angiosperms – flowering plants – Monocots – grassy plants – Dicots – broadleaf plants
Plant Classification Example: “live oak”
Kingdom – Plantae (“plants”) Phylum (or Division) – Magnoliophyta (“flowering plants”) Class – Magnoliopsida (“dicots”) Order – Fagales Family – Fagaceae Genus – Quercus (“oaks”) species – virginiana (“live oak”)
Principles of Identification • Differences based on: – reproductive structures (cones, flowers or fruit) – habitat/range – tree form – twigs, buds – bark, wood – leaves
Principles of Identification • Differences based on: – reproductive structures (cones, flowers or fruit) – habitat/range – tree form – twigs, buds – bark, wood – leaves
Principles of Identification • Differences based on: – reproductive structures (cones, flowers or fruit) – habitat/range – tree form – twigs, buds – bark, wood – leaves
Principles of Identification • Differences based on: – reproductive structures (cones, flowers or fruit) – habitat/range – tree form – twigs, buds – bark, wood – leaves
Principles of Identification • Differences based on: – reproductive structures (cones, flowers or fruit) – habitat/range – tree form – twigs, buds – bark, wood – leaves
Principles of Identification • Differences based on: – reproductive structures (cones, flowers or fruit) – habitat/range – tree form – twigs, buds – bark, wood – leaves
Leaf Key for Texas Trees My tree has… Leaves that are very large, and fan‐shaped
Leaves that are compound, opposite
Leaves that are feather‐like
Leaves that are compound, alternate
Leaves that are needle‐like
Leaves that are simple, opposite
Leaves that are scale‐like or awl‐like
Leaves that are simple, alternate
Leaf Key for Texas Trees My tree has… 1) Leaves that are feather‐like, AND… Leaves that are deciduous; male flower clusters are
