400 FLORA. 



4. Sagina saginoides (L.) Britton. Arctic Pearlwort. (I. F. f. 14.97.) 

 Perennial, glabrous, tutted, 2- 10 cm. high, few-flowered or the flowers solitary at 

 the ends of the stems. Leaves linear-subulate, or filiform, 4.-10 mm. long, acumi- 

 nate or mucronate; flowers 3-5 mm. broad; sepals, petals and styles 5; stamens 10 ; 

 sepals oval, obtuse, half the length of the ovoid-oblong capsule. On rocks, Lab., 

 Anticosti and in arctic America. Also in the higher Rocky Mts., south to Colo. 

 and Utah, in Cal., and in alpine and arctic Europe and Asia. Summer. 



5. Sagina nodosa (L.) Fenzl. Knotted Pearlwort. (I. F. f. 1498.) 

 Perennial, tufted, 5-15 cm. high; stems glabrous, or slightly glandular-pubescent 

 above. Lower leaves linear, teretish, 8-16 mm. long, mucronulate, the upper 

 shorter and with clusters of minute ones in their axils; flowers few, about 6 mm. 

 broad; sepals, petals and styles 5; stamens 10; sepals ovate-oblong, obtuse; petals 

 ol>ovate, longer than the calyx, as is also the ovoid pod. In wet, sandy places, 

 coast of Mass. to Greenland; shores of Lake Superior, Lake Winnipeg and of the 

 Arctic Sea. Also in northern Europe and Asia. Summer. 



15. ARENARIA L. (See Appendix.) 



Mainly tufted herbs, with sessile leaves, and terminal cymose or capitate, rarely 

 solitary, white flowers. Sepals 5. Petals 5, entire or scarcely emarginate, rarely 

 none. Stamens 10. Styles generally 3 (rarely 2-5). Ovary I -celled, many- 

 ovuled. Capsule dehiscent at the apex by as many valves or teeth as there are 

 styles, or twice as many. Seeds reniform-globose or compressed. [Latin, sand, in 

 allusion to the habitat of many species.] About 150 species, of wide distribution. 



Valves of the capsule 2-cleft or 2-toothed, sometimes appearing as if double the number 

 of the styles. 



Leaves ovate or oblong. 



Sepals acute or acuminate ; annual herb of waste places. 1. A. serpylli/olia. 

 Sepals obtuse or scarcely acute ; perennial ; arctic. 2. A. ciliata. 



Leaves subulate or setaceous. 



Cymes very dense ; stems 2-10 cm. tall. 3. A. Hookeri. 



Cymes loose ; stems 1-4 dm. tall. 4. A. Fendleri. 



Valves of the capsule entire (Genus Alsine Wahl). 

 Leaves rigid, subulate or setaceous. 



Arctic or alpine, densely tufted, 2-8 cm. high. 



Flowers 10-16 mm. broad. 5. A. biflora. 



Flowers 4-6 mm. broad. 6. A. verna. 



Neither arctic nor alpine, tufted but diffuse, 1-4 dm. high. 



Leaves densely imbricated ; pine barren species. 7. A. Caroliniana. 



Leaves fascicled in the axils. 



Sepals ovate or ovate-lanceolate. 4 mm. long ; plant bright green. 



8. A. Michauxii. 

 Sepals narrowly lanceolate, long-acuminate, 5 mm. long ; plant pale 

 green. 9. A. Texana. 



Leaves soft, herbaceous, narrowly linear or filiform. 



Sepals prominently ribbed ; southern. 10. A. patula. 



Sepals not ribbed ; alpine and northern. 11. A. Groenlandica. 



i. Arenaria serpyllifolia L. Thyme-leaved Sandwort. (I. F. f. 1499) 

 Annual, slender, slightly downy-pubescent, widely branched, 0.5-2 dm. high. 

 Leaves ovate, 4-8 mm. long, acute; pedicels 4-12 mm. long ; bracts ovate, resem- 

 bling the leaves; flowers 4 mm. broad or less, very numerous in cymose panicles; 

 sepals ovate, acute or mucronate, 3-5 -nerved; petals obovate or oblong, usually 

 shorter; capsule ovoid, dehiscent by 6 short apical valves; seeds rough. In dry or 

 rocky places, throughout eastern N. Am. Naturalized from Europe. May-Aug. 



2. Arenaria ciliata L. Fringed Sandwort. (I. F. f. 1500.) Perennial, 

 tufted, glandular-puberulent; stems very slender, creeping or ascending, pubescent 

 in lines, 2-13 cm. long, or the flowering branches erect. Leaves ovate or oblong, 

 sessile or very nearly so, 2-6 mm. long, ciliate or glabrous; peduncles filiform, 

 erect, mostly I -flowered; flowers about 6 mm. broad; sepals ovate or oblong, ob- 

 tuse, nerveless or faintly I -nerved, about as long as the petals; capsule oblong, 

 twice as long as the calyx, its 3 valves deeply 2-cleft; seeds slightly roughened. 

 Ouebec to Greenland. Also in arctic and alpine Europe. Summer. 



3 Arenaria Hookeri Nutt. Hooker's Sandwort. (1. F. f. 1501.) Tufted 

 from a deep woody root, 2- 10 cm. high. Leaves linear-subulate, rigid, very 



