BUCKWHEAT FAMILY. 149 



1. PTEROSTEGIA F. & M. 



Very slender weak diffused annuals, dichotomous from the tase, 

 with opposite leaves. Involucres nearly sessile in the forks and 

 terminal, consisting of a single bract, subtending and shorter than 

 the solitary sessile flower, rounded and more or less 2-lobed or dentate 

 on the margin, in fruit enlarged, scarious and reticulated, loosely 

 enclosing the achene and with 2 sac-like gibbosities on the back. 

 Calyx 6, rarely 5-parted; stamens 3 or 6. (G-reek pteron, a wing, 

 and stegia, a covering, in reference to the involucre.) 



1. P. drymarioides P. & M. Stems commonly several from 

 the base usually with a branch at each node, diffuse or straggling, 

 from a few in. to 1 ft. long; leaves roundish or broader than long and 

 notched once or twice at apex or even cleft, or distinctly fan-shaped 

 or obcordate, 3 to 6 lines broad, narrowed at base to a slender but 

 mostly short petiole; flower reddish, less than 1 line long; perianth 

 segments lanceolate. 



Open woods under Oaks or in the shade of rocky outcroppings: 

 Berkeley; Mt. Diablo and southward to Southern California. Sierra 

 Nevada. Last of Apr.-May. 



2. LASTARRI/EA Kemy. 



Small fragile annual, diffusely branched from the base. Leaves 

 linear, in oauline whorls and in a radical tuft which disappears early. 

 Floral bracts in whorls, with hooked awns. Involucre none. Flowers 

 sessile in the forks and terminal. Calyx simulating an involucre, 

 tubular, 5 to 6-cleft to the middle, the teeth with recurved hooked 

 awns. Stamens 3, inserted on the throat, with a small membranous 

 tooth on each side of the filaments. (Jose Victorino Lastarria, 1817- 

 1888, Chilean publicist and writer on the constitutional history of 

 Chile.) 



1. L. Chilensis Remy. Branches 2 to 4 or 8 in. long; floral 

 bracts concealing the flowers; perianth 1 to 1^ lines long. 



Introduced from Chile. Antioch; southward to Fresno and Mon- 

 terey Cos. and Southern California. May-June. 



3. CHORIZANTHE E. Br. 



Low dichotomously branched annual herbs of summer, with 

 rosulate radical leaves (which disappear early in the dry season). 

 Cauline leaves opposite or ternate, frequently reduced and bracteate, 

 the bracts sometimes unilateral. Involucres (in ours) 1-flowered; ' 

 tubular or funnel-form, always sessile, 3 to 6-angled or -costate, and 8 

 to 6-toothed or -cleft; teeth divaricate, cuspidate or awned, the awns 

 very frequently with a hooked tip. Flowers pedicellate or nearly 

 sessile, ebracteolate, included within the involucre or the segments 

 protruding. Calyx 6-parted or -cleft, often colored, never herbaceous. 

 Stamens usually 9 (seldom 3 or 6), adnate to the base of the tube. 

 Ovary glabrous. Embryo with inflexed or straight radicle. (Greek 

 chorizo, to divide, and anthos, flower, on account of the parted 

 perianth.) 



