226 CONTRIBUTIONS FEOM THE NATIONAL HEBBAEIUM. 



12. ANTJLOCAULIS Standley. 



Stout perennial herb; leaves mostly basal, nearly orbicular, lacerate-marginecl 

 or dentate, thick and leathery; stems much branched, glabrous but with viscid rings 

 about the internodes; flowers in small clusters, sessile or pedicellate; perianth funnel- 

 form, with a long tube; fruit biturbinate, 10-ribbed. 



1. Anulocaulis leiosolenus (Torr.) Standley, Contr. U. S. Nat. Herb. 12: 375, 

 1909. 

 Boerhaavia leiosolena Torr. U. S. & Mex. Bound. Bot. 172. 1859. 

 Type locality: "In gypseous soil, Great Canon of the Rio Grande, 70 miles below 

 El Paso," Texas. 

 Range: Western Texas and southeastern New Mexico. 



New Mexico: Near Lakewood (Wooton). In gypsum soil, in the Lower Sonoran 

 Zone. 



13. BOERHAAVIA L. 



Slender annual or perennial herbs, glabrous or pubescent, often with glandular 

 rings about the internodes; leaves opposite, unequal, petiolate or sessile; flowers 

 small, variously arranged, each usually subtended by 1 or 2 minute bracts; perianth 

 campanulate, 5-lobed; stamens 1 to 5, exserted or included; fruit clavate to obpyram- 

 idal, 3 to 5-ribbed or angled, or sometimes with 3 to 5 low thick wings. 



KEY TO THE SPECIES. 



Perennials. 



Leaves linear or narrowly linear-lanceolate 1. B. tenuifolia. 



Leaves broadly ovate. 



Flowers solitary, on long slender pedicels. 



Fruit glabrous; flowers about 1 mm. broad 4. B. organensis. 



Fruit viscid; flowers 3 to 5 mm. wide 5. B. gracillima. 



Flowers short-pediceled, in umbels. 



Stems hirsute below 2. B. ixodes. 



Stems glabrous or puberulent below 3. B. viscosa olig- 



adena. 

 Annuals. 



Flowers in slender spikes or racemes. ^ 



Ptibs of the fruit 4; fruit truncate or very obtuse at the 

 apex; bracts large, persistent; stems mostly erect, 



sparingly branched 6. B. wrightii. 



Ribs of the fruit 5; fruit rounded at the apex; bracts 

 small, deciduous; stems decumbent or ascending, 



much branched 7. B. torreyana. 



Flowers not spicate or racemose. 



Fruit rounded at the apex, subtended by large reddish 



persistent bracts; plants glandular 8. B. purpurascens. 



Fruit tnincate at the apex; bracts minute, green, decidu- 

 ous; plants glabrous or nearly so. 

 Leaves thick and fleshy, very glaucous, especially 

 beneath, oblong; flowers in simple umbels, 

 short-pediceled; stems decumbent or ascend- 

 ing 9. B. intermedia. 



Leaves thin, not conspicuously glaucous, paler 

 beneath, broadly ovate; flowers in compound 



umbels; stems erect 10. B. erecta thorn- 



beri. 



