WOOTON AND STANDLEY FLORA OF NEW MEXICO. 305 



64. ROSACEAE. Rose Family. 



Herbs, shrubs, or trees with alternate stipulate leaves (stipules often fugacious) and 

 perfect flowers; hypanthium saucer-shaped, sj^herical, turbinate, or tubular, often 

 margined by a disk bearing the stamens; sepals and petals normally 5, rarely of a 

 different number, the petals wanting in one genus; stamens numerous, sometimes 

 reduced to 5; carpels 1 to many, dry or fleshy, dehiscent in a few genera; fruit of 

 achenes, follicles, or druplets (in some genera the receptacle accrescent). 



KEY TO THE GENERA. 



Hypanthium constricted at the throat, fleshy or prickly, 

 wholly inclosing the achenes. 

 Hypanthium in fruit becoming more or less fleshy, 

 not supplied with hooked bristles; carpels 



numerous; shrubs 1. Rosa (j). 306). 



Hypanthium dry, the top surrounded by numerous 



hooked bristles; carpels few; herbs 2. Agkimonia (p. 309). 



Hypanthium not constricted at the throat, neither fleshy 

 nor prickly, at most loosely investing the fruits. 

 Fruit consisting of 1 to 5 dehiscent follicles. 



Seeds winged; leaves persistent 21. Vauquelinia (p. 321). 



Seeds not \vinged ; leaves deciduous. 



Follicles more or less united at the base; 

 leaves broadly ovate, lobed, 2 to 4 



cm. long 3. Opulaster (p. 309). 



Follicles distinct (usually 5); leaves very 



small, spatulate, 1 cm. long or less. . 4. Petrophyton (p. 310). 



Fruit usually consisting of numerous indehiscent 



carpels, these becoming either achenes or 



drupelets. 



Carpels becoming more or less fleshy drupelets. 



Styles filiform; stigmas capitate; leaves 



compound; stems spiny 18. Rubus (p. 319). 



Styles club-shaped; stigmas 2-Iobed; leaves 

 simple; stems unarmed. 

 Drupelets capped by hard hairy cush- 

 ions; stems suffrutescent, dying 

 back most of their length each 

 winter; leaves large; fruit pleas- 

 antly acid, pulpy 19. Rubacer (p. 320). 



!^ Drupelets without cushions; stems 



nearly all woody; leaves small; 



fruit usually dry 20. Oreobatus (p. 320). 



Carpels becoming dry achenes. 



Styles articulated to the ovary, deciduous; 

 herbs (except Dasiphora). 

 Styles terminal or nearly po; ovules 



pendulous and anatropous 6. Potentilla (p. 310). 



Styles lateral or basal; ovules not pen- 

 dulous. 

 Styles nearly basal; ovules ascend- 

 ing or erect, orthotropous. . .11. Drymocallis (p. 316). 

 52570°— 15 20 



