Key to Trees: GROUP A

GROUP A: Simple leaves, alternately attached

1. The trees have acorns. (Look for acorns or acorn caps still attached to tree, or acorns on the ground.) Buds are clustered at the ends of twigs. (OAKS) Go to #2
+ The trees don’t have acorns Go to #7
2. The leaves do NOT have prominent lobes Go to #3
+ The leaves DO have prominent lobes Go to #4
3. The leaves are small and thick, with pointed tips. Leaves remain attached through the winter. Not native to NCTx, but frequently cultivated here.


+ The leaves are large and have large, coarse teeth


4. The leaves have bristle tips Go to #5
+ The leaves do not have bristle tips. Go to #6
5. Leaves have 5-9 lobes with bristle tips



(Note: Shumard Oaks predominate east of NCTx, Texas Red Oaks to the west. Within NCTx, these two frequently hybridize.)
+ The leave have 3 lobes with bristle tips, are leathery and dark green, glossy on top. Bark is very dark


6. The leaves have rounded lobes, with the end lobe largest. Acorns are huge


+ The leaves often have five rounded lobes, forming a cross shape, but leaf shape is quite variable. Acorns are small.


7. The branches/twigs are armed. (They have thorns, spines, etc.) Go to #8
+ The branches/twigs are NOT armed. (no thorns or spines) Go to # 11
8. The leaves are toothed Go to #9
+ The leaves are NOT toothed; leaf margins are smooth. Go to # 10
9. The leaves are about as wide as long, have large teeth and sometimes lobes. Thorns are slender and attach near where leaf attaches.


+ The leaves are finely toothed, and appear somewhat “wilted.” They are longer than wide, and have a long pointed tip. Bark is very dark


10. The leaves are small (2-3” long,) thick and fairly stiff. They have a broad tip and narrow to the stem. They cluster on spurs.


+ Leaves are large and broad, most >4” long; with long pointed tip. Go to #24
11. Leaves toothed, but very variable in shape, even on the same tree: some lobed, some mitten-shaped, some not lobed; fruit an elongated berry.


+ The leaves are not highly variable, including lobed and unlobed leaves on the same tree. Go to #12
12. The leaves are roughly oval, oblong, or egg-shaped Go to #17
+ The leaves are NOT oval, oblong, or egg-shaped. Go to #12
13. The leaves are very long and narrow. (over 3” long, about ½” wide). The bark is very dark, furrowed, often twisted.


+ The leaves are about as wide as they are tall. Go to #14
14. The leaves are roughly triangle/heart shaped. Go to #15
+ The leaves have spiky lobes, roughly star-shaped. Go to #16
15. The leaves are triangle shaped, with toothed margins


+ The leaves are heart shaped, with smooth margins. Pink flowers in the spring, before leaves appear.


16. The leaves are star shaped. Spiky balls remain on tree.


+ The leaves have 3-5 shallow lobes and large teeth. Distinctive peeling bark exposes light underbark. Ball are not spiky


17. The leaves are asymmetrical at their bases. Go to #18
+ The leave are symmetrical at their bases Go to # 23
18. The leaves have three basal veins: three main veins coming from the leaf base; secondary veins come from all three main veins. Leaves usually have mostly smooth margins, or only a few teeth.


+ The leaves have pinnate venation (veins like a feather: one central vein with secondary veins coming off the central vein.) The leaves are toothed, often double-toothed. Go to #19
19. The leaves are only slightly asymmetrical at the base, leaves smooth and shiny. Bark is mottled with orangish areas. (Non-native tree, usually cultivated)


+ Leaves are strongly asymmetrical at the base, teeth usually doubly-serrate: each tooth has a break or cut on one side. Go to #19
20. The leaves are large, typically 2-5” long. Length of the leaf is usually about twice its width. Go to #21
+ The leaves are small, typically 1-3” long. Length is usually less than twice the width. Twigs often have corky “wings.” Go to #22
21. The leaves are smooth to slightly rough on top; on most leaves, few secondary veins fork well before the edge. (no more than 1-2 per side.)


+ The leaves are quite rough on top; on most leaves, several secondary veins fork well before the edge. (more than 2 per side)


22. The leaves have pointed tips, smooth or slightly rough on top, flowers in the spring. Usually has corky wings on twigs


+ The leaves have wide, rounded tips, are rough on top; flowers in the fall. Sometimes has corky wings on twigs


23. The leaves are large, usually 4 or more inches long. Go to #24
+ The leaves are small, have indistinct teeth, often red berries Go to #25
24. The leaves have conspicuously parallel secondary veins and have finely toothed to smooth margins.


+ The leaves are large, without teeth, and without conspicuously parallel secondary veins. Go to #25
25. Leaves are ovate (wider at the bottom than top,) with long pointed tips. Wood deeply furrowed, showing orange where exposed, especially exposed roots. Twigs produce a sticky, milky sap when broken.


+ The leaves have smooth margins, and back of leaf much lighter than front. The bark on a young tree is grayish brown with orange tint in fissures. When mature, it is very dark, deeply divided into small blocks, resembling charcoal briquettes. (AKA as alligator-skin bark). Fruit orange when ripe, with a four-sided cap which remains after the fruit has fallen.


26. The leaves are evergreen, smooth, abruptly narrowed at base


+ The leaves are wider near the tip, tapering to base, fuzzy underneath, not stiff.


Return to KEY TO TREES Main Page

Posted on 29 March, 2020 22:43 by lisa281 lisa281


This is a work in progress. It's part of a simplified key to trees that I've been working on, for a presentation to the BPTMN 2020 training class. Class is on hold for now, so I'm sharing it here first!

Posted by lisa281 about 4 years ago

Add a Comment

Sign In or Sign Up to add comments