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center.—Prairies and dry plains, abundant west of the Mississippi. Very variable. Var. 
NUDA Gray has sparse and loose pubescence, green and soon glabrate rigid leaves, 
and short bracts; var SPINULOSA Gray is a canescent form with aristately prolonged 
and rigid bracts; var. ARISTATA Gray is loosely hairy and green (or becoming gla- 
brous), with narrowly linear bracts 2 to 3 times the Jength of the flowers. 
** Flowers subdiecious or polygamo-cleistogamous : in fertile flowers corolla closed over 
maturing pod and forming a kind of beak: anthers not exserted: sterile flowers with 
spreading corolla and long-exseried filaments: seeds mostly flat. 
4. P, Virginica L. Hairy or hoary-pubescent, 10 to 25 em. high: leaves oblong, 
varying to obovate and spatulate-lanceolate, 3 to 5-nerved, slightly or coarsely and 
sparingly toothed, short-petioled or subsessile, 2.5 cm. or so long: spikes mostly 
dense, 2.5 to 5 cm. long: stamens 4: seeds usually 2.—Sandy fields, etc., extending 
from the Atlantic region to southern and western Texas. Var. LONGIFOLIA Gray, @ 
Texan form, is a coarser plant, with oblong-spatulate leaves 7.5 to 12.5 cm. long and 
tapering into a margined petiole, often with some coarse salient teeth; spikes 12.5 
to 30 cm. long. 
5. P. heterophylla Nutt. Leaves linear or filiform, rather fleshy, acute, entire, 
or some of them 2 to 4-lobed or toothed: flowers very small: spike slender: stamens 
2: pod oblong-conoidal, 10 to 28-seeded, nearly twice the length of the calyx and 
bract.—Low sandy ground, extending from the interior and Gulf region into Texas. 
