52 MISC. PUBLICATION 423, U. S. DEPT. OF AGRICULTURE 



29. Pistil more than 1; stamens usually numerous (30). 



30. Seeds with a fimbriate aril and a copious endosperm, reniform; 

 plants shrubby; leaves without stipules. 



52. Crossosomataceae. 



30. Seeds not arillate, the endosperm scanty or none; plants small 



trees, shrubs, or herbs; leaves usually with stipules. 



53. Rosaceae. 



29. Pistil 1 (exceptionally 2 or 3 in genus Purshia) , simple or compound 



(if the carpels several and almost separate, then the plant a very 



thornv shrub with the leaves reduced to scales) ; stems commonly 



woody (31). 



31 . Ovary 1 -celled; plants mostly shrubs or small trees (32) . 



32. Leaves reduced to small scales, these imbricate and covering 

 the twigs; flowers minute, in elongate spikelike inflores- 

 cences 78. Tamaricaceae. 



32. Leaves with well-developed blades (33). 



33. Styles 3; fruit a small drupe; leaves compound or simple. 



67. Anacardiaceae. 

 33. Style 1 or none; fruit dry, an achene or follicle; leaves 

 simple, sometimes deeply cleft (34) . 

 34. Stamens more than 10; flowers with a turbinate or funnel- 

 form hypanthium, or the pistil enclosed in a sheathlike 

 extension of the disk: Genera Purshia, Coleogyne. 



53. Rosaceae. 

 34. Stamens .10; hypanthium none; pistil not enclosed in a 



sheath : Genus Forsellesia 68. Celastraceae. 



31. Ovary with 2 or more cells (35). 



35. Leaves reduced to small scales; plant with sharp-pointed rigid 

 spiny branches; carpels 5 or more, nearly separate, in fruit 



a circle cf 1-seeded drupes 60. Simarubaceae. 



35. Leaves with well-developed blades (36). 



36. Plants vinelike, the stems climbing or trailing; fruit, a berry. 



72. Vitaceae. 

 36. Plants not vinelike (37) . 



37. Leaves punctate with translucent glands; fruit a capsule 



or a nearly orbicular samara 59. Rtttaceae. 



37. Leaves not punctate with translucent glands (38). 



38. Fruit a pair of laterally winged samaras, these united 

 near the base; leaves simple and palmately lobed, 

 or palmately divided, or pinnate with few leaflets. 



69. Aceraceae. 

 38. Fruit not a pair of samaras (39). 

 39. Leaves simple (40). 



40. Fruit not fleshy; stamens alternate with the 

 petals 68. Celastraceae. 



40. Fruit a more or less fleshy drupe; stamens opposite 



the petals 71. Rhamnaceae. 



39. Leaves pinnate; fruit drupelike or berrylike (41). 



41. Fruit 3-angled, dry; bark and foliage strong- 



scented 61. BURSERACEAE. 



41. Fruit globose, with translucent pulp; bark and 

 foliage not strong-scented: Genus Sapindus. 



70. Sapindaceae. 

 28. Flowers without a disk, or this represented by separate glands or 

 scales, or rudimentary; stamens not borne on the throat of the 

 calyx cr, if so, not more than 12 (42). 

 42. Filaments united, at least at base (43). 



43. Plants vinelike, the stems climbing or trailing; calyx throat 



bearing a conspicuous fringed crown _ 83. Passifloraceae. 



43. Plants not vinelike; calyx throat not with a fringed crown (44). 



44. Carpels adnate to a central column, from which they or the 



persistent styles become more or less detached at maturity. 



55. Geraniaceae. 

 44. Carpels not adnate and separating as in the foregoing (45). 

 45. Leaves compound, often sensitive (46). 



