138 POLYGONACEAE. 



3. P. aviculareL. Wire Grass. Yard Grass. Stems wiry, minutely 

 striate, prostrate, often several feet long, flowering from the base; herbage 

 glabrous and green; leaves oblong, acute, 3 to 6 lines long; flowers on very 

 short pedicels, 2 lines broad when expanded; calyx cleft, the oblong lobes white 

 with a green center; stamens 8, the 3 inner with dilated bases; styles 3, very 

 short; achene ovoid, dark brown, minutely granular. 



Naturalized from Europe: common in hard, especially beaten soils, and 

 sometimes in cultivated lands; flowering through the dry season and until 

 after the rains break. 



4. P. spergulariaeforme Meisn. Annual, much branched and somewhat 

 diffuse, or sparingly branched and more strictly erect, 4 to 13 in. high; sheaths 

 with a short mostly scarious base and lacerate summit; leaves linear or oblan- 

 ceolate, 1-nerved, acute, 6 to 13 lines long; spikes 4 in. long or less, very 

 slender, the flowers much scattered below, crowded above; calyx rose-color or 

 white; stamens 8, included, the filaments hardly dilated at base; style as long 

 as the ovary, 3-parted. — (P. coarctatum Dougl.) 



Dry hills: northern Sonoma Co., Mt. St. Helena, and northward to the Mt. 

 Shasta region. Oct. 



5. P. californicum Meisn. Annual, 3 to 7 in. high; diffusely branched 

 just above the base, the stems slender and wiry, the ultimate branches elon- 

 gated and fioriferous; herbage glabrous, but the brownish stems striate and 

 minutely scabrous; leaves linear to filiform, cuspidate, 3 to 6 lines long, not 

 jointed to the sheathing stipules which are deeply lacerate-f ringed and imbri- 

 cated on the upper portion of the very slender and elongated spike's; bracts 

 subulate, 1 or 2 lines long; flowers solitary and sessile in each axil; sepals 

 white with rose-colored midvein; achene narrowly lanceolate, slightly exserted; 

 styles slightly divergent. 



Dry hills: North Coast Ranges; Sierra Nevada. 



6. P. parryi Greene. Dwarf compact annual, commonly branching from 

 base, 1 to 2 in. high; stems rigid and brittle, bearing flowers even to the 

 base ; leaves narrowly linear, acute, cuspidate, 1 to 2 lines long ; stipules so 

 extremely lacerate as to appear cottony, and often hiding the flowers; flowers 

 solitary and sessile in the axils, the bract broad, laciniate to the middle; 

 stamens included; style 3-parted; achene triangular. 



Sierra Nevada; higher North Coast Ranges, Howell Mt. and northward. 



7. P. amphibium L. Water Persic aria. Aquatic glabrous perennial 

 with stout stems not branching above the rooting base; leaves floating, ellip- 

 tical to oblong or oblong-lanceolate, truncate or rounded at base, 2 to 7 in. 

 long on petioles T -, in _ ' •_. in. long; sheaths leaf -bearing at about the middle; 

 spike terminal, dense, ovate or oblong, % to 1 in. long, on a commonly short 

 peduncle; calyx bright rose-color, l 1 /. to 3 lines long, the 5 stamens and 2-cleft 

 Style exserted; achene lenticular, smooth. 



Ponds and lakes in the Coasl Ranges and Sierra Nevada and also in sloughs 

 of the interior valleys. Far northward and eastward. Often terrestrial and 

 almost equally successful as a land or water plant. Var. hartwrightii Bissel. 

 Differing in its rough-hairy Bheaths which are ciliate and usually with an 

 abruptly spreading herbaceous margin. — Sierra Nevada and far eastward (P. 

 hartwrightii Gray). 



8. P. muhlenbergii Wats. Perennial, aquatic or in half dry places; leaves 

 and upper portion of fche Bimple stem appressed-hirsutulose or scabrous, the 



