15. 
16. 
17. 
18. 
19: 
20. 
21. 
22. 
23. 
24. 
25. 
26. 
27. 
28. 
29. 
KryYS—LEAVES OPPOSITE xili 
LEAVES OPPOSITE. 
Leaves represented by small persistent scales. 16. 
Ordinary leaves, or their scars, present. 19. 
Twigs often ending in spines. 17. 
Twigs not sharp and pungent. p. 6. Ephedra. 
Spines much flattened. p. 214. Colletia. 
Twigs cylindrical (terete). 18. 
Spines rather long: no stipules. p. 241. Koeberlinia. 
Spines 2 cm., outcurved: stipules minute. p. 221. Adolphia. 
Leaf-scars and buds in 2 vertical ranks. 20. 
Leaf-scars in 4 ranks unless on climbers. 22. 
Deciduous: without stipules or stipule-scars. 21. 
Evergreen: stipules persistent. p. 159. Guaiacum. 
Not aromatic: buds elongated. p. 43. Buckleya. 
Aromatic: buds round. p.67. Meratia. 
Climbing or scrambling. 23. 
Not climbing. 35. 
Climbing by coiling leaf-organs (tendrils). 24. 
Climbing by aerial roots. 25. 
Twining or scrambling, without aerial roots or tendrils. 28. 
Wood showing a cross in section. p. 338. Bignonia. 
Wood not showing a cross: stem angled.  p.52. Clematis. 
Evergreen: leaves rather small. p. 195. Evonymus. 
Deciduous. 26. 
Leaf-scars half-round: bundle-trace 1. p. 339. Campsis. 
Leaf-scars crescent-shaped. p. 81. Hydrangea. 
Leaf-scars U-shaped or horseshoe-shaped: pith spongy. 27. 
Leaf-scars U-shaped: bundle-traces 5. p. 78. Schizophragma. 
Leaf-scars horseshoe-shaped. p. 79. Decumaria. 
Pith continuous. 29. 
Pith spongy: evergreen: sap milky. 30. 
Pith chambered or excavated. 32. 
Tiwegs acutely 4-lined. p. 320. Jasminum. 
Twigs terete and not ribbed. _ p.330. Petraea. 
