612 CONTEIBUTIONS FROM THE NATIOISTAL HERBARIUM. 



Styles 2 or more times dichotomous or, if once dichotomous, the 

 branclies not entire. 

 Leaves usually glandular-ciliate, entire or nearly so. 



Stipules very short and inconspicuous ; ciliation of the leaves 



inconspicuous 24. C. humilis. 



Stipules long and conspicuous ; ciliation of the leaves very 

 conspicuous. 

 Stamens about 40; divisions of the stipules long and slen- 

 der ; style branches entire 25. C. ciliato-glandulosus. 



Stamens about 30; divisions of the stipules short aud 



stout; style branches laciniate 26. C. pulcher. 



Leaves not ciliate, dentate. 



Bracts laciniate 27. C. ovalifolius. 



Bracts entire. 



Leaves denticulate 28. C. stylosus. 



Leaves coarsely duplicate-dentate 29. C. macrodontus. 



AA. Stipules entire. 



Style branches 2 or more times dichotomous, often laciniate. Leaves 



coarsely dentate 30. C. repens. 



Style branches once dichotomous. 



Stamens 20 to 50. Leaves with glands at base. 



Stamens 35 to 50; leaves serrulate 31. C. xalapensis. 



Stamens 20 to 30 ; leaves entire 32. C. subfragilis. 



Stamens 6 to 20. 

 Leaves with large glands on the lower surface at the base. 



33. C. mexicanus. 

 Leaves without glands, or these very obscure. 



Pistillate racemes very dense and congested in fruit, many- 

 flowered ; pistillate flowers sessile or nearly so. 



Leaves entire, long-petiolate 34. C. cladotriclius. 



Leaves repand-dentate 35. C. francoanus. 



Pistillate racemes lax, usually few-floweretl, if dense the 

 pistillate flowers long-pedicellate. 

 Leaves rounded or very obtuse at apex. 

 Loaves mostly palmate-nerved at base ; pistillate sepals 



accrescent 36. C. corymbulosus. 



Leaves pinnate-nerved ; sepals not accrescent. 

 Base of the leaf broadly rounded or subcordate ; leaves 



mostly oval 37. C. ehrenbergii. 



Base of the leaf cuneate or obtuse ; leaves mostly 



oblong or ovate-oblong 38. C. torreyanus. 



Leaves, at least most of them, acute or acuminate. 

 Stipules large, semireniform, foliaceous, persistent. 



39. C. alamosanus. 

 Stipules small, linear or subulate, early deciduous. 



Leaves pinnate-nerved, the basal nerves not con- 

 spicuous. 

 Leaves perfectly glabrous on the upper surface. 



40. C. cortesianus. 

 Leaves pubescent on the upper surface. 



Leaves thin, green on the upper surface, soon 

 glabrate 41. C. miradorensis. 



