198 CONTEIBUTIONS FROM THE NATIONAL HERBAEIUM. 



Order 24. CHENOPODIALES. 



KEY TO THE FAMILIES. 



Fniit a capsule, dehiscent by apical or longitudi- 

 nal valves. 



Ovary several-celled; corolla wanting 47. AIZOACEAE (p. 228). 



Ovary 1-celled ; corolla usually present. 



Sepals 2 48. PORTULACACEAE (p. 229). 



Sepals 4 or 5. 



Sepals distinct; petals not clawed; 



ovary sessile 49, ALSINACEAE (p. 234). 



Sepals united ; petals clawed ; ovary 

 more or less distinctly 8tipitate...50. SILENACEAE (p. 240). 

 Fruita utricle, achene, or anthocarp, indehiscent, 

 circumscissile, or bursting irregularly. 

 Fruit an anthocarp, the achene surrounded 



by the tube of the corolla-like calyx . . .45. ALLIONIACEAE (p. 216). 

 Fruit not an anthocarp. 



Fruit an achene or berry 46. PHYTOLACCACEAE Cp. 228). 



Fruit a utricle. 



Stipules present, scarious 44. CORRIGIOLACEAE (p. 216). 



Stipules wantiug. 



Bracts scarious 43. AMARANTHACEAE (p. 209). 



Bracts not scarious 42. CHENOPODIACEAE (p. 198). 



42. CHENOPODIACEAE. Goosefoot Family. 



Annual or perennial herbs or shrubs; leaves usually simple, alternate, sometimes 

 much reduced; flowers perfect or unisexual, small, apetalous, the sepals sometimes 

 wanting, replaced in the pistillate flower by a pair of scales, these becoming variously 

 modified in fruit; sepals 5 or fewer, the stamens as many and opposite them; pistil 1, 

 with a single ovule; fruit an achene or utricle. 



The family is a very important one in the arid regions, where representatives are 

 numerous both as to species and individuals. They seem to be particularly adapted 

 to bright sunlight and dry soil, and are tolerant of alkali. Several of the species are 

 important forage plants, a few are eaten by man, and several are troublesome weeds. 



KEY TO THE GENERA. 



Embryo spirally coiled; leaves fleshy (except in no. 2), 



linear or awl-shaped. 



Shrubs, 1 to 3 meters high, with monoecious flowers; 



staminate flowers spicate, without a perianth; 



pistillate flowers solitary, axillary; fruiting calyx 



wiaged • 1. Sarcobatus (p. 199). 



Herbs, at most suffrutescent, the stems 150 cm. high or 

 less; flowers perfect; fruiting calyx winged or 

 naked . 

 Fruiting calyx winged; leaves spiny; plants be- 

 coming tumbleweeds 2. Salsola (p. 199). 



Fruiting calyx not winged; leaves fleshy; not 



tumbleweeds. 3. Dondia (p. 200). 



Embryo annular; leaves mostly flat and broad (linear in no. 

 7, scalelike in no. 4). 

 Stems and branches jointed (younger parts terete and 



and very succulent); leaves scalelike 4. Allenrolfea (p. 201). 



