FLOWERING PLANTS AND FERNS OF ARIZONA 519 



but affixed at the middle; flowers mostly perfect, some of them often 

 cleistogamous and apetalous, axillary or terminal, solitary or in small 

 clusters; calyx bearing 8 to 10 external glands; petals 5, yellow or 

 orange, abruptly contracted into the claws; stamens 5 or 6, some of 

 them often sterile. 



Key to the genera 



1. Carpels each with a conspicuous scarious dorsal wing, the wings divergent; 

 leaf blades lance-linear; petals yellow, entire or denticulate. 



1. Janusia. 



1. Carpels not winged, nutlike, irregularly triangular, strongly keeled on the 

 back, the edges margined or tuberculate; leaf blades oblong-lanceolate, 

 oval, or ovate ; petals orange, fimbriate 2. Aspic a rp a . 



1. JANUSIA 



Stems slender, twining, often tangled; leaves short-petioled, the 

 blades narrow; fruit a pair of samaras (exceptionally 3). 



1. Janusia gracilis A. Gray, PL Wright. 1: 37. 1852. 



Mohave County to Greenlee, Cochise, Santa Cruz, Pima, and Yuma 

 Counties, 1,000 to 5,000 feet, dry rocky slopes, April to October. 

 Western Texas to Arizona and northern Mexico (including Baja 

 California) . 



2. ASPICARPA 



Stems commonly trailing; leaves sessile or short-petioled, the blades 

 oblong-lanceolate to ovate; flowers dimorphous, the petaliferous ones 

 mostly in terminal clusters, the cleistogamous flowers axillary, long- 

 peduncled to nearly sessile; fruit a pair of strongly keeled, usually 

 tuberculate nutlets. 



1. Aspicarpa hirtella Rich., Paris Mus. Hist. Nat. Mem. 2: 399. 1815. 



Cochise, Santa Cruz, and Pima Counties, 4,000 to 5,500 feet, 

 commonly in chaparral, August and September. Southern Arizona 

 and Mexico. 



The Arizona specimens all appear to belong to one species, although 

 identified variously as A. longipes Gray, A. humilis (Benth.) Juss., 

 and A. hirtella. As these species are defined by Niedenzu 76 the 

 description of A. hirtella seems to apply best to the Arizona plant. 



63. POLYGALACEAE. Milkwort family 



Plants annual or perennial, herbaceous or suffruticose ; leaves 

 alternate, opposite, or verticillate, sessile or short-petioled, simple, 

 entire; flowers perfect, very irregular; sepals 5, the lateral ones more 

 or less petaloid; petals commonly 3, more or less united or adnate 

 to the stamens, the lower petal concave or keellike, often crested or 

 beaked; stamens 6 to 8, the filaments united below into a tuba, the 

 anthers opening by pores; fruit a flat 2-celled capsule; seeds usually 

 carunculate (appendaged around the hilum) . 



Key to the genera 



1. Petals united below into a dorsally cleft tube, the lower one (keel) united at 

 base with the staminal tube; fruits dehiscent, not sharply keeled or 

 prominently veined 1. * Polygala. 



1. Petals nearly or quite separate, the lower one not united with the staminal 

 tube, more or less enclosing the connivent upper petals; fruits Lndehiscent. 

 sharply keeled, prominently reticulate-veined 2. Moninna. 



™ Niedenzu, Franz, malpighiaceae. Pflanzenreieh IV. 141: 247-870. 1928. (See p. 560.) 



