Flora of the Palouse Region 63 



are included in the ocreae: akenes 3-angled, dull, minutely granular. 

 Everywhere a weed; much relished by stock. 



P. douglasii Greene. Annual: stems slender, 15-40 cm. tall, erect, glab- 

 rous or nearly so; branches few, erect: leaves lanceolate, acute at each end, 

 sessile at the jointed base: ocreae cylindric, scarious, becoming cut into lobes: 

 flowering branches slender: flowers 1-3 from the axils of the scattered bracts, 

 soon becoming deflexed: calyx purple or whitish, with prominent green mid- 

 ribs: styles very short: akene 3-angled, black, shiny. In gravelly soil, not 

 common. 



var. latifolium Engelm. Not so tall : leaves broader and shorter: flowering 

 branches more leafy. Gravelly soil in pine woods, Thatuna Hills. 



P. majus Piper, n. comb. {P. coarctatum maj'us Meisn.) Annual, much 

 branched from the base, erect or nearly so: stems wiry, terete, inconspicu- 

 ously striate: leaves linear-lanceolate, 2-6 cm. long, jointed at base; ocreae 

 scarious, about 2 cm. long, at length cut into slender lobes: spikes elongate, 

 5-12 cm. long: flowers remote, short-pedicelled, horizontal or spreading; 

 bracts consisting of the scarious ocreae and short subulate blades, about as 

 long as the buds: calyx broadly campanulate, 4-5 mm. long, white, with 

 simple green midveins, reaching the apex of the short rounded lobes: styles 

 separate for one-half their length: fruit reflexed; akene black, shiny, smooth, 

 3-angled, acuminate, 3-3.5 mm. long. Common in stony soil. Differs from 

 true P. coarctatum in the following points: flowers larger, white, not pink; 

 scattered not congested; segments with simple midveins having at most two 

 or three branches, not much-branched: styles split only half way, usually 

 two-thirds or more in P. coarctatum: ocreae more tardily lacerate. 



P. watSOIli Small. Annual, glabrous: stems very slender, 3-10 cm. tall, 

 with few branches: leaves linear, 1-3 cm. long: ocreae scarious, cut into lobes: 

 spikes few, rather dense, 4-12 mm. long: bracts green, linear, acuminate, 

 longer than the pink flowers, the margins revolute: stamens 3-5: akenes 

 minutely striate. Basalt outcroppings, Pullman, rare. 



P. polygaloides Meisn. Annual, glabrous: stems slender, much branched 

 from the base, 5-20 cm. tall: leaves linear, sessile, i-nerved, 1-3 cm. long; 

 ocreae scarious, parted into long lobes: spikes dense, numerous, terminal, 

 5-10 cm. long; bracts oblong, with a broad white margin, crenulate, obtuse 

 or acuminate, exceeding the flower: stamens 8: akene 3-angled, long, acum- 

 inate, longitudinally striate. Moist meadows, frequent. 



P. persicaria L. Annual, erect or ascending, glabrous or puberulent: 

 stems 15-90 cm. long: leaves lanceolate, acute or acuminate at each end, 

 short- petioled, 5-25 cm. long, frequently with a brown-purple spot near the 

 middle, glabrous or sparsely puberulent below and on the midrib and mar- 

 gins above; ocreae tubular, 1-1.5 cni - long, coarsely fringed: spikes slender, 

 2-4 cm. long, slender peduncled, erect: calyx pink, 5-lobed: akene lenticular, 

 black and shining. Sparingly introduced. 



P. lapathifolium k- Very similar to the above: nodes more or less swollen; 



ocreae naked or entire: flowers white or pale rose. 



var. incanum Koch. Leaves small, 2-4 cm. long, tomentose beneath: 

 spikes 1-3 cm. long. 



var. incarnatum Wats. Leaves large, 20 cm. long, glabrous: spikes some- 

 what nodding, slender, 5-10 cm. long. 



Only the varieties occur within our limits, banks of Snake River, in- 

 frequent. 



