WOOTON AND STANDLEY FLORA OF NEW MEXICO. 217 



KEY TO THE GENERA. 



Involucre gamophyllous, calyx-like. 



Involucre 3-parted; fruit lenticular, with lateral 



wings usually armed with teeth 1. Wedeliella (p. 218). 



Involucre 5-parted; fruit oblong, turbinate, or al- 

 most spherical, never with toothed wings. 

 Fruit with 5 prominent ribs; involucre en- 

 larged and membranous in fruit, with 

 1 to 3 flowers; perianth usually cam- 



panulate 2. Allionia (p. 219). 



Fruit smooth or slightly 5-angled; involucre not 

 membranous, usually not enlarged in 

 fruit. 

 Involucre 1-flowered, campanulate; tube 



of the perianth long and slender 3. Mirabius (p. 221). 



Involucres with 3 or several flowers; peri- 

 anth various. 

 Involucre rotate, 3-flowered; perianth 

 small, short-funnelform, almost 



campanulate 4. Allio.viella (p. 222). 



Involucre campanulate or tubular, 

 with usually more than 3 flow- 

 ers; perianth large, funnelform, 

 with a long and conspicuous 



tube 5. Quamoclidion (p. 222). 



Involucre polyphyllous, consisting of 1 to many small 

 bracts, these often deciduous. 

 Stigmas linear; inner cotyledon abortive. 



Wings completely encircling the fruit, hyaline, 

 membranous; flowers mostly tetramer- 



ous 6. Tripterocalyx (p 



Wings not completely encircling the fruit, thick 

 and coriaceous or wanting; flowers pen- 



tamerous 7. Abronia (p. 223). 



Stigmas spherical or hemispherical; cotyledons 

 more or less unlike but neither abortive 

 Flowers in heads, these surrounded by a regu- 

 lar many-bracted involucre; stamens 



long-exserted; fruit turbinate, 10-ribbed. 8. Nyctaoima (p. 224). 

 Flowers not in heads, each flower with an in- 

 volucre of ] to 3 bracts; fruit various. 



Fruit conspicuously winged 9. Seltnocabpus (p 



Frail not winged. 



Fruit asymmetrical, gibbous; inflores- 

 cence racemose 10. Ctphombris (p ' 



Fruit symmetrical, never gibbous; in- 

 florescence various 

 Perianth LO cm, long, \\ ith a I 

 ami very slender tube; 



flowers axillary 11. A.clei8anthbs 



Perianth smaller, 2 cm long or 

 the tube much shorter 

 and le • >n pi 

 wantin 



