FLOWERING PLANTS AND FERNS OF ARIZONA 315 



cymes or corymbs, showy; calyx not conspicuously ribbed; petals 

 pink or red, with or without appendages; stamens 10; styles 2. 



Key to the species 



1. Plant annual; flowers in a broad open flat-topped corymbiform panicle; calyx 

 ovoid, strongly 5-angled; petals rose red, not appendaged_ 1. S. vaccaria. 



1. Plant perennial; flowers in compact cymes, these forming a more or less 

 elongate panicle; calyx cylindric (rarely ovoid), not angled; petals nor- 

 mally pale pink, appendaged with long subulate teeth at the junction of 

 the blade and claw 2. S. officinalis. 



1. Saponaria vaccaria L., Sp. PL 409. 1753. 



Vaccaria vulgaris Host, Fl. Austr. 1: 518. 1827. 



Tucson, Pima County (Tourney 461), April and May. A field weed 

 here and there in the United States ; naturalized from Europe. Scarcely 

 established in Arizona. 



Cow soap wort. The seeds contain saponin and may be somewhat 

 poisonous. 



2. Saponaria officinalis L., Sp. PI. 408. 1753. 



Prescott (Yavapai County), well established in waste land, mid- 

 summer. Widely distributed in the United States; naturalized from 

 Europe. 



Bouncing-bet. The leaves and roots contain saponin and form a 

 lather in water. The plant has been used medicinally, as a tonic, etc. 



41. CERATOPHYLLACEAE. Hornwort family 



1. CERATOPHYLLUM. Hornwort 



Plant aquatic, submersed; stems slender, much-branched; leaves 

 whorled, dissected into filiform segments; flowers unisexual, minute, 

 axillary, sessile, subtended by a many-cleft involucre simulating a 

 perianth; stamens numerous; pistil with a 1-celled ovary and an elon- 

 gate filiform style. 



1. Ceratophyllum demersum L., Sp. PL 992. 1753. 



San Bernardino, Cochise County (Mearns 2538), Gila Crossing, 

 Pinal County (Wooion in 1914) . Throughout most of North America; 

 Europe. 



42. RANUNCULACEAE. Crowfoot family 



Plants mostly perennial, herbaceous or suffrutescent ; leaves alternate 

 or opposite, simple or compound; flowers mostly perfect, regular or 

 irregular; perianth in one series or of both a calyx and a corolla; 

 stamens often numerous; pistils usually several; ovary 1-celled; 

 ovules 1 to many; fruit either follicular (dehiscent on 1 suture) or 

 indehiseent achenes or berries. 



This large and diverse family contains some of the showiest of 

 Arizona wild flowers, notably the columbines, larkspurs, and monks- 

 hoods. 



Key to the genera 



1. Carpels with 2 or more ovules; fruit follicular or (in Actaea) berry like (2). 

 2. Flowers irregular, large and showy, commonly blue or bluish (3). 

 3. Upper sepal extended into a conspicuous cylindric spur. 



5. Delphinium. 



