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Section II. Key to Keys
- The University Press of Kentucky
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SECTION II. KEY TO KEYS 1. Woody plants EITHER with succulent stems or leaves (cactus or yucca) OR with grasslike habit (wild cane with parallel-veined leaves and hollow stems)________________________________________Key A, p. 23. 1. Woody plants lacking succulent parts and grasslike habit (woody vine, subshrub, shrub, or tree). 2. Gymnosperms; mostly trees (shrubby in species of Taxus and Juniperus); leaves needlelike or scalelike, arrangement various, but if clustered then needles 2–5 in number; leaves evergreen in all genera except Taxodium (note fallen twigs with linear leaves, and branches with globose seed cones and/or pendulous panicles of immature pollen cones, these with pinelike odor); seeds borne naked, in cones (except in Taxus) ______________________________________________________________________ Key B, p. 23. 2. Angiosperms; trees, shrubs, or woody vines; leaves evergreen or deciduous, typically with a flat blade and not needlelike (if somewhat needlelike then plants shrubby, and EITHER with leaves in clusters of 6 or more and minty aromatic or punctate, as in Conradina and Hypericum, OR stems jointed with nodal rings, as in Polygonella); seeds enclosed in a fruit, the remnant fruits sometimes present in winter. 3. Leaves evergreen, typically with thick texture and green color. 4. Leaves opposite or whorled _______________________________________________ Key C, p. 24. 4. Leaves alternate _________________________________________________________Key D, p. 25. 3. Leaves deciduous, absent in winter (some species with persistent, tardily deciduous, remnant leaves, these turning brown). 5. Plants with armature (thorns, spines, or prickles) ______________________________ Key E, p. 27. 5. Plants lacking armature. 6. Stems viny, requiring support, either climbing by tendrils, aerial roots, or by twining, or trailing and usually rooting at nodes; plants in this category do not produce erect stems ⬎ 30 cm tall that are capable of supporting their own weight (some Vitis species may be shrublike and lack tendrils, but have shreddy bark and brown pith with a partition at the node, unlike any species in following categories) ________________________________________________ Key F, p. 29. 6. Stems erect, either trees or shrubs, or if sprawling or trailing, then producing erect stems ⬎ 30 cm tall, only rarely rooting at the nodes, as in Decodon. 7. Leaf scars opposite or whorled. 8. Leaf scars of young twigs joined around the twig or connected by lines (connecting lines may be obscured in older twigs) ____________________________________Key G, p. 31. 8. Leaf scars of young twigs not joined or connected by lines around the twig _______________________________________________________________Key H, p. 33. 7. Leaf scars alternate. 9. Catkins or densely flowered racemes present in winter __________________Key I, p. 34. 9. Catkin-like structures absent in winter. 10. Twigs with encircling stipular scars, these ⬎ ¾ encircling the twigs at each node, OR with leaf scars ⬎ ½ encircling the twigs __________________________ Key J, p. 35. 10. Twigs lacking encircling stipular scars, or if present then ⬍ ¾ encircling the twigs, and leaf scars ⬍ ½ encircling the twig. 11. Pith not solid and continuous, either chambered or diaphragmed or with spongy cavities or hollow__________________________________________ Key K, p. 35. 11. Pith solid and continuous, lacking cavities or partitions. 12. Bundle scar clearly 1 (obscure in Cytisus, with twigs green, angled, and flexible) _____________________________________________________ KEY L, p. 36. 12. Bundle scars 3 or more (if obscure, then twigs not as described above). 13. Twigs with true end buds OR end buds clustered ________KEY M, p.37. 13. Twigs lacking true end buds, the false end buds not clustered (lateral buds sometimes clustered or superposed) ___________________KEY N, p. 40. ...