Flora of the Palousc Region 73 



Perennial: seeds with a strophiole: leaves flat and green. 



Sepals obtuse, shorter than the petals. A. lateriflora. 



Sepals acuminate, longer than the petals. A. macrophylla. 



Perennial: seeds without a strophiole: leaves narrow and sharp. 



A. CONGESTA. 



Annual: leaves very small. A. pusilla. 



A. lateriflora L. Mostly puberulent throughout: stems slender, ter- 

 ete, erect or decumbent, simple or few-branched, 10-30 cm. high: leaves 

 elliptic or oblong, sessile, obtuse, 1-2 cm. long: cymes few-flowered: sepals 

 obtuse or acutish, 2 mm. long, one half the length of the obovate petals. Hill- 

 sides, not rare. 



A. macrophylla Hook. Minutely puberulent: stems erect or decumbent, 

 angled, 5-10 cm. tall, mostly simple: leaves lanceolate, acute at each end, 

 2-6 cm. long: cymes few-flowered: sepals ovate-lanceolate, acuminate, 3 mm. 

 long, exceeding the petals. Common in dry pine woods. 



A. COngesta Nutt. Usually glabrous throughout: stems tufted, erect, 

 15-40 cm. tall; joints prominent: leaves narrowly linear, rather rigid, sharp- 

 ly cuspidate, 2-5 cm. long, the cauline pairs rather distant: flowers con- 

 gested into 1-3 heads: bracts scarious: sepals ovate-lanceolate, acuminate, 

 3-nerved, 3-4 mm. long, shorter than the petals, scarious-margined. In 

 rock crevices, summit of Cedar Mountain. 



A. pusilla Wats. Wholly glabrous: stems very slender, usually branch- 

 ed, 2-8 cm. high: leaves oblong or ovate, 2-3 mm. long, distant: sepals lan- 

 ceolate, acuminate, 2-2.5 mm - long: petals wanting. Stony soil, common 

 but very inconspicuous. 



no. SPERGULA. 



Annual branched herbs: leaves subulate, apparently whorled, 

 with scarious stipules: flowers in a eyinose panicle: sepals 5, white: 

 stamens 10, rarely 5: ovary i-celled: capsule-valves 5, opposite 

 the sepals. 



S. arvensis L. Minutely and sparsely glandular throughout: stems sev- 

 eral, mostly simple below the inflorescence, 30-50 cm. long, decumbent or 

 ascending: leaves narrowly linear, 2-3 cm. long, in whorls of 6-15: flowers 

 in a loose cyme, the pedicels becoming deflexed: petals white, 4-5 mm. long, 

 equalling or exceeding the sepals: capsule ovoid; seeds black, acutely mar- 

 gined, minutely roughened. Sparingly introduced into grain fields. 



in. SPERGULARIA. 



Low annual biennial or perennial herbs: leaves fleshy, linear or 

 setaceous, with scarious stipules: flowers in terminal racemose 

 cymes: sepals 2: petals 5, rarely fewer or none, purplish or white: 

 stamens 2-10, commonly 10: styles 3, very rarely 5; ovary i-celled: 

 capsnle-valves as many as the styles, when 5, alternate with the 

 sepals. 



.Stipules silver}', conspicuous, lanceolate. S. RUBRA. 



Stipules small, triangular. S. diaxdra. 



