7. P. fastigiàta, Nutt. Stem slender, at length corymbosely branched; leaves narrowly linear, acute, 3–8´´ long; spikes short and dense (3´´ in diameter); the small rose-purple flowers on pedicels of about the length of the pod; wings obovate- or oval-oblong, narrowed at the base, scarcely exceeding the pod; bracts deciduous with the flowers or fruits, caruncle as long as and nearly enveloping the stalk-like base of the minutely hairy seed.—Pine barrens of N. J. and Del. to Ky., and southward.
8. P. Nuttàllii, Torr. & Gray. Resembles the last, but usually lower; spikes cylindrical, narrow; flowers duller or greenish purple, on very short pedicels; the awl-shaped scaly bracts persistent on the axis after the flowers or fruits fall; seed very hairy, the caruncle smaller.—Dry sandy soil, coast of Mass. to Mo., and southward.—Spike sometimes rather loose.
9. P. Curtíssii, Gray. Slender (9´ high), leaves, etc., as in the two preceding, flowers rose-purple, in usually short racemes; pedicels about equalling or exceeding the persistent bracts; the narrow oblong erect wings fully twice the length of the pod; caruncle small, on one side of the stalk-like base of the very hairy seed, which is conspicuously apiculate at the broader end.—Md. to Ga.—The species was founded upon an abnormal form with elongated racemes and pedicels.
[*][*][*] Annuals with at least the lower stem-leaves whorled in fours, sometimes in fives; spikes terminating the stem and branches; fl. summer and autumn.
[+] Spikes short and thick (4–9´´ in diameter); bracts persisting after the fall of the (middle-sized) rose or greenish purple flowers; crest small.
10. P. cruciàta, L. Stems (3–10´ high) almost winged at the angles, with spreading opposite branches; leaves nearly all in fours, linear and somewhat spatulate or oblanceolate; spikes sessile or nearly so; wings broadly deltoid-ovate, slightly heart-shaped, tapering to a bristly point or rarely pointless; caruncle nearly as long as the seed.—Margin of swamps, Maine to Va. and southward near the coast, and west to Minn. and Neb.
11. P. brevifòlia, Nutt. Rather slender, branched above; leaves scattered on the branches, narrower; spikes peduncled; wings lanceolate-ovate, pointless or barely mucronate.—Margin of sandy bogs, R. I., N. J. and southward.
[+][+] Spikes slender (about 2´´ thick), the bracts falling with the flowers, which are small, greenish-white or barely tinged with purple, the crest of the keel larger.
12. P. verticillàta, L. Slender (6–10´ high), much branched; stem-leaves all whorled, those of the (mostly opposite) branches scattered, linear, acute; spikes peduncled, usually short and dense, acute; wings round, clawed; the 2-lobed caruncle half the length of the seed.—Dry soil; common.
Var. ambígua. Leaves (and branches) all scattered or the lowest in fours; spikes long-peduncled, more slender, the flowers often purplish and scattered. (P. ambigua, Nutt.)—N. Y. to Mo., and southward.