82 ALSINACEAE 



Capsule short, ovate or oblong, opening with usually 6 valves; styles usually 3. 



1. AlSINE. 



Capsule long, cylindrio, often curved, opening with usually 10 teeth at the apex ; 

 styles usually 5. 2. Cerastium. 



Capsule opening with as many, entire or at length 2-cleft, valves as there are styles; 

 petals entire or merely notched at the apex (except in Arenaria Kingii). 

 Styles fewer than the sepals, or rarely of the same number and then opposite 

 them. 

 Flowers with a rather prominent, glandular, 10-lobed disk under the ovary; 

 plants fleshy. 3. Ammodenia. 



Flowers with no or a very inconspicuous disk; plants scarcely fleshy. 

 Seeds with a basal membranous appendage (strophiole) at the hylum. 



4. MOEHMNGIA. 

 Seeds not strophiolate. 



Valves of the capsule entire. 5. Aisnsovsia. 



Valves of the capsule at last 2-cleft. 6. Abenaria. 



Styles as many as the sepals and alternate with them. 7. Sagina. 



Stipules present. 



Leaves whorled; styles 5. 8. Spekgitla. 



Leaves opposite; styles usually 3. 



Styles distinct; sepals not spinulose-tipped. 9. TissA. 



Stigmas sessile; sepals spinulose-tipped. 10. Loeflingia. 



1. ALSINE L. Chickweed, Starwort. 



Plant not viscid. 



Basal leaf-blades spatulate to rhombic-obovate, petioled; plants annual. 

 Leaf-blades aU ovate or rhombic-ovate. 



Flowers cymose. 1. A media 



Flowers sohtary in the axils. 18. A . washingtoniana. 



Stem-leaves small, lanceolate. 2. A. nitens. 



All leaves sessile. 



Upper bracts at least scarious; perennials with rootstocks. 

 Petals minute or none. 



Leaves oblong-lanceolate; branches of the inflorescence at last reflexed. 



3. A. baicalensis. 

 Leaves linear; branches of the inflorescence ascending. 



4. A. alpestris. 

 Petals equaUing or exceeding the sepals. 



Leaves broadest at about the middle, narrowed at the base. 



5. A. longifolia. 

 Leaves broadest near the base. 



Calyx 4—5 mm. long; stem not villous. 



Stem 2-3 dm. high, many-flowered; leaves narrowly lanceolate to 

 nearly lineEir. 

 Sepals lanceolate, very acute, nearly equalling the capsule. 



6. A. strictiflora. 

 Sepals ovate or ovate-lanceolate, obtuse or mucronate, scarcely 



more than half as long as the mature capsule; pedicels in 

 fruit spreading. 7. A. Umgipes. 



Stem 3-15 cm. high, usually 1-3-flowered, rarely 4-6-flowered. 

 Leaves narrowly lanceolate; sepals lanceolate, very acute. 



8. A. laeta. 

 Leaves ovate or ovate-lanceolate; sepals ovate-lanceolate, ob- 

 tusish. 9. A. Edwardsii. 



Calyx 2-3 mm. long; stem 1 dm. high or less. 3-10-flowered, usually 

 villous. 10. A. subvestita. 



None of the bracts scarious. 



Leaves linear to lanceolate, more than four times as long as broad; plants 

 perennial, with running rootstocks. 

 Petals equalling or exceeding the sepals. 



Plant low, less than 1 dm. high, bluish green. 8. A. laeta. 

 Plant slender, light green, more than 1 dm. high. 



11. A. crassifolia. 

 Petals much shorter than the sepals, or none. 



Sepals with narrow scarious margins, acute; leaves oblong-lanceolate, 

 narrowed at the base; midrib not unusually strong; petals usually 

 lacking. 12. A. borealis. 



Sepals with broad scarious margins, acuminate; lea,ves Unear-lanceolate. 

 with a strong midrib; petals usually present. 

 Leaves 2-8 mm. wide, broadest near the base. 



13. A. bTachypetala. 

 Leaves 8-15 mm. wide, broadest near the middle. 



14. A. oxyphylla. 

 Leaves ovate-lanceolate, ovate or oval, less than four times as long as broad; 



cespitose perennials, except No. 18. 

 Leaves thin. 



Stem glabrous or nearly so. 



Sepals acute or acuminate. 15. A. crispa. 



Sepals obtuse. 16. A. obtusa. 



Stem distinctly pubescent. 



Leaves sessile; flowers more or less cymose. 17. A. calycantha. 



