P0LYG0HE3!. 41 



in the axils of short leafy branohlets, each involucrate with a sheath-like 

 scarious bract on the joint of the short pedicel: sepals 1% lines long, 

 rose-color or white, slightly spreading. — Plentiful near the Soda Springs 

 above Napa; also in Sonoma Co. Aug. — Oct. 



■*— -i— Annuals, with striate stems and less conspicuous sheaths; branches 

 leafy to the summit, floriferous throughout. 



3. P. aviotjlabe, L. Stoutish, much branched, prostrate, the branches 

 1 — 3 ft. long: herbage glabrous, bluish-green: leaves oblong or lanceolate, 

 acutish, % — 2% in. long: fl. on very short pedicels: sepals 1 line long, 

 green, with white or rose-colored margin: achene broadly ovale, 1 line 

 long or less, dull black and minutely granular. — A prevalent weed in 

 summer fields and vineyards. April — Oct. 



4. P. coarctatum, Dougl. Erect, freely branching, the herbage 

 more or less scabro-puberulent throughout: leaves firm in texture, acute: 

 fl. spicate-crowded and on erect pedicels: sepals rose-color or white with 

 only a broad midvein of green: achenes very minutely punctate toward 

 the apex. — Petrified Forest, Sonoma Co. July — Sept. 



* ~* Leaves not jointed with the petiole, striately 3-nerved; sheaths %-lobed 



or fimbriate ; stamens 8, the inner S scarcely dilated. 



5. P. Californicum, Meisn. Erect, slender, 3—6 in. high, panicled- 

 spicate, the stem and branches glabrous, dark brown: leaves rigid, linear 

 or filiform, %—±}£ in. long, pungently acute: spikes very slender, elon- 

 gated, the subulate bracts 1 — 2 lines long; sheaths 1 line long, deeply 

 lacerate-f ringed, nearly equalling the pale rose-colored flowers: achene 

 narrow, slightly exposed; styles slightly divergent. — Valleys and dry 

 hills of the interior, near Napa, etc. July — Sept. 



* * * Leaves not jointed, more ample, pinnately veined; sheaths cylin- 



drical, oblique or truncate; fl. in dense spikes or loose cymelets; 



stamens 4 — #> <M the filaments filiform; styles deciduous, 



often only 2 and the achene lenticular. 



+- Weedy annuals of fields and gardens. 



6. P. nodosum, Pers. Stoutish, erect or ascending, 1 — 4 ft. high, 

 freely branching, glabrous except the rough glandular peduncles, and 

 scabrous leaf-margins and veins beneath; stem often purple-dotted 

 throughout: leaves lanceolate, 2 — 5 in. long, acuminate, short-petioled; 

 sheaths naked in age, glandular-ciliolate when young: spikes linear, 

 usually drooping, 1 in. long or more: fl. white or pale rose, 1 line long: 

 stamens 6: styles 2: achene lenticular, ovate. — Very common in culti- 

 vated lands, preferring moist places. July— Oct. 



