NYCTAGINACEAE 451 



2. CLADOTHRIX Nutt. 



Stellate-pubescent annuals or woody-based perennials with opposite leaves. 

 Flowers axillary, solitary or in small glomerules, perfect, subtended by 3 

 small bracts and by foliaceous involucral bracts. Sepals 5, equal, thin, 

 pubescent. Stamens 5, arising from the margin of a short cup-shaped 

 hypogynous disk, with 5 short teeth alternating with the filaments. Achene 

 subglobose, indehiscent. Species 3, southern United States and Mexico. (Greek 

 klados, branch, and thrix, hair, in reference to the stellate covering.) 



1. C. oblongifolia Wats. White-woolly perennial; stems widely branch- 

 ing, forming low broad mound-like plants 9 to 15 inches high and 1^ to 3 

 feet broad ; leaves roundish ovate, obtuse, 3 to 10 lines long, shortly petioled ; 

 involucral bracts united and forming definite involucres; involucres panicu- 

 lately disposed, subsessile or shortly peduncled, their tubes oblong-turbinate, 

 1 to 1% lines long, their lobes 3, foliaceous, round-ovate, 1 to 2 lines long; 

 sepals ovate-lanceolate, 1 line long. 



Sandy washes; Colorado Desert and eastern Mohave, north into Inyo Co. 

 Arizona, southern Nevada. 



Locs. Milpitas, Colorado River, Jepson 5283; Salton, Parish; Bagdad, T. Brandegee; Death 

 Valley, ace. Coville. Ash Mdws., Nev., Purpus 6025. 



Refs. CLADOTHRIX OBLONGIFOLIA Wats. Proc. Am. Acad. 17: 376 (1882), type spms. from 

 the Colorado River (Chimney Peak, Newberry, and Yuma, Pringle) and the Mohave Desert, 

 Warm Sprs., S. B. & W. F. Parish 1346; Cov. Contrib. U. S. Nat. Herb. 4: 179 (1893). 

 C. cryptantha Wats. Proc. Am. Acad. 26: 125 (1891), based on spms. by Parry (e. Colorado 

 Desert) and by Orcutt 2186 (Carrizo Creek, San Diego Co.); Parish, Zoe, 5: 113 (1901). 

 C. lanuginosa Wats. Bot. Cal. 2: 43 (1880), not Nutt. With each flower-cluster set in an in- 

 volucral cup, C. oblongifolia is sharply separated from C. lanuginosa Nutt., which has solitary 

 flowers and its involucral bracts quite distinct. The latter species occurs in Arizona and may 

 yet be found in southeastern California. 



Alternanthera achyrantha R. Br. Prodr. 1: 417 (1810). Prostrate annual 

 with opposite leaves; leaves broadly ovate or obovate, shortly acute or mucro- 

 nate, 5 to 11 lines long, cuneately narrowed at base into a petiole ; flowers per- 

 fect, in short white spikes ; spikes dense, mostly axillary, solitary or clustered, 

 3 to 6 lines long; sepals 5, lanceolate, unequal, 2 more carinate-concave, all 

 woolly on the back with barb-tipped hairs; stamens 5, with 5 alternating 

 sterile filaments, all united at base into a cup-like disk; achene flattened, 

 indehiscent. Native of Mexico, locally introduced at Los Angeles (Erythea, 

 1: 99). 



NYCTAGINACEAE. FOUR-O'CLOCK FAMILY. 



Ours more or less succulent herbs or low shrubs with opposite entire leaves 

 and commonly swollen joints. Flowers perfect, regular, subtended by bracts 

 which often form a calyx-like involucre. Bracts or involucres often colored. 

 Calyx plicate in the bud, tubular, colored like a corolla and very delicate, 4 

 or 5-lobed, the lower part of its tube circumscissile and leaving a persistent 

 base which is closely constricted over but not attached to the superior ovary. 

 Corolla none. Stamens in ours 3 to 5 (or 7), mostly unequal, hypogynous 

 (or perigynous in Abronia). Ovary 1-celled, 1-ovuled; style and stigma 1. 

 Fruit an achene, closely invested by the base of the calyx-tube, which be- 

 comes very much hardened and is often striate, ridged, or winged. Embryo 

 mostly coiled, with mealy endosperm; cotyledons 2, or only 1 in Abronia by 

 reduction. Genera 20 and species about 200 ; all continents but mainly Ameri- 

 can. 



Bibliog. Gray, A., Some new Gen. and Sp. of Nyctaginaceae, prin. coll. in Tex. and New 

 Mex. (Am. Jour. Sci. ser. 2, 15: 259-263, 319-324, 1853). Rydberg, P. A., Nyctaginaeeae of 

 Rocky Mt. Reg. (Bull. Torr. Club, 29, 680-693, 1902). Jones, M. E., Nyctaginaceae of the 

 Great Plateau (Contrib. 10: 34-54, 1902). Standley, P. C., Allioniaeeae of the United States 



