ROBINSON. — ALSINE&. 275 
11. Arenaria. Sepals 5. Petals as many, white or nearly so, 
entire or emarginate (very rarely minute or wanting). Stamens 10, 
or often fewer by abortion. Styles 3 or 4. Seeds many. 
++ ++ Styles as many as the sepals and alternate with them. 
12. Sagina. Sepals 5, (rarely 4). Petals as many, entire or 
emarginate, white, rarely obsolete. Stamens usually 5, less frequently 
3-10. Valves of the capsule as many as the sepals, and opposite 
them. Seeds several to many. 
* * Stipules present, scarious: petals undivided. 
13. Spergularia. Sepals 5. Petals 5 (rarely fewer or none), 
reddish or white. Stamens commonly 10. Styles 3 (very rarely 5); 
ovary I-celled ; valves of the capsule as many as the styles, when 5 
im number alternate with the sepals. Seeds often margined. Leaves 
linear or filiform. 
14. Spergula. Sepals 5. Petals 5. Stamens 10 (rarely 5). 
Styles 5 ; ovary unilocular, many-ovuled. Valves of the capsule 5, 
°pposite the sepals. Seeds acutely margined or narrowly winged. 
ves narrow, linear, verticillate and fascicled in the axils. 
Trine II. POLYCARPE. Including genera 15-18. (See 
Am. Acad. xxviii. 126.) 
; 8. HOLOSTEUM, L. (6dos, all, and éaréov, bone; used iron- 
leally, since the plants are soft and weak.) — A small genus of Old 
“orld annuals and biennials much resembling Cerastium except 
os inflorescence and seeds. The commonest species is adventive in 
America, — Gen. no. 928; Reichb. Icon. Fl. Germ. v. t. 221; Gay, 
Ann. Sci. Nat. ser. 3, iv. 23; Benth. & Hook. Gen. i. 148. 
H. UMBELLATUM, L. Finely glandular-pubescent, somewhat glau- 
“ah stems 3-18 inches high: leaves sessile, ovate-oblong : umbels 
: ‘flowered, terminal upon long naked peduncles; pedicels 8-12 
Mes long, some of them reflexed: filaments shorter than the calyx. —_ 
Neo 88; Eng. Bot. i. 27. Locally naturalized in Pennsylvania, 
™ o> and Delaware, Porter, Austin, Canby, Small. (Adv. 
ur. 
9. CERASTIUM, L. Movse-£ar CHICKWEED. (xépas, & 
ae from the elongated curved capsules.) — Annuals or perennials, 
ually pubescent and often viscid. Leaves usually flat. Flowers 
White, borne in more or less expanded leafy or naked cymes. A genus — 
cinstishea from Stellaria and Arenaria somewhat by habit, but = : 
¥; although not always satisfactorily, by the form and dehis ca 
