296 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



sepals 5, separate or united below; petals none; ovary superior, 

 1- to 5-celled. 



Key to the genera 



1. Capsule dehiscent by valves; calyx of 5 distinct sepals, these not append- 



aged _ 1. Mollugo. 



1. Capsule circumscissile; calyx 5-lobed, the lobes usually with a thick dorsal 

 ridge ending in a free hornlike tip, the margins thin and petallike (2). 



2. Styles 3 to 5; ovary 3- to 5-celled; seeds many 2. Sesuvium. 



2. Styles 1 or 2; ovary 1- or 2-celled; seeds few 3. Trianthema. 



1. MOLLUGO. Carpetweed 



Plants not fleshy; stems prostrate or erect; leaves narrow, mostly in 

 whorls of 3 to 6; sepals white within; stamens 3 to 5; capsules lon- 

 gitudinally dehiscent, 3- to 5-celled. 



Key to the species 



1. Stems commonly prostrate, radiating from the root, not filiform, green; stem 

 leaves mostly oblanceolate and more than 1 mm. wide; seeds reniform, 

 red brown, very shiny, with several parallel ribs along the back and 

 sides 1. M. verticillata. 



1. Stems erect or ascending, filiform, straw-colored; stem leaves linear or linear- 

 lanceolate, commonly about 1 mm. wide; seeds irregularly obovoid, dark 

 brown, scarcely shiny, finely reticulate 2. M. cerviana. 



1. Mollugo verticillata L., Sp. PL 89. 1753. 



Cochise, Santa Cruz, and Pima Counties, 2,500 to 5,000 feet, 

 commonly in sandy soil, September to October. Widely distributed in 

 North America; Eastern Hemisphere. 



Sometimes called Indian-chickweed. 



2. Mollugo cerviana (L.) Seringe in DC, Prodr. 1: 392. 1824. 



Pharnaceum cervianum L., Sp. PI. 272. 1753. 



Coconino County to Cochise and Pima Counties, 1,300 to 7,000 

 feet, sandy soil, August to October. Texas to California and south 

 to tropical America; Eastern Hemisphere. 



2. SESUVIUM. Sea-purslane 



Plant fleshy; leaves opposite, the blades narrow, usually oblance- 

 olate; stipules none; petioles more or less connate at base; perianth 

 5-lobed, the lobes purplish within, the tube turbinate; stamens 

 numerous, inserted on the perianth tube. 



1. Sesuvium verrucosum Raf., New Fl. 4: 16. 1838. 



Sesuvium sessile Robinson in A. Gray, Syn. Fl. I 1 : 259. 1897- 

 Not of Pers. 



Maricopa and Yuma Counties, 1,000 feet or lower, saline soil, 

 March to November. Arkansas to California, south to tropical 

 America. 



3. TRIANTHEMA 



Plant somewhat fleshy; leaves with stipules, opposite, those of the 

 pair very unequal in size, the blades obovate, cuneate at base; perianth 

 purplish within, the lobes concave, with a hornlike dorsal appendage; 

 stamens 6 to 10; capsule crested. 



