FLAX TRIBE 



47 



high. The ovate leaves are (ringed and slightly stalked ; floivers 

 larger and with more conspicuous feials than ii: A. serpylUfolia. 

 Rare, limestone district of Sligo, Ireland.— ^Fl. July. Perennial. 



8. A. trinervis (Three-nerved Sandwort). — Leaves egg-shaped, 

 acute, the lower ones stalked, 3-5 nerved, Iringed ; flowers solitary 

 from the forks of the stf-m and axils ; sepals vncrved, the central 

 nerve rough. A weak, strangling jilant, al)out a foot long, a]i- 

 proaching the chickweed (Stellana metha) in haliit, from which, 

 however, it may at once be distinguished by its undivided petals. 

 — Fl. May, June. Annual. 



13. Cerastium [Mouse-ear Chickweed) 



1. C. viilgaiiim (Mouse-ear Chickweed). — A com- 

 mon annual weed, downy and geneially viscid, 

 with straggling branched stems 1-2 feet long, and 

 inconspicuous flowers, of which the petah are 

 usually shorter than the calvx. or occasionally 

 wanting. The seed-vessels when ripening lengthen 

 beyond the calyx and become curved. An in- 

 definite number of very confusing varieties occur, 

 which it is unnecessary to describe here. — Fl, all 

 the summer. 



2. C. arvense (Field Mouse-ear Chickweed). — 

 An uncommon species, smaller than the fore- 

 going, less downy and viscid ; leaves narrower, and 

 with conspicuous white flowers, with petals twice 

 as long as the sepals. — Fl. June, July. Perennial. 



3. C. Alpiniim (Alj)ine Mouse-ear Chickweed). — A short plant 

 wiih ascending stems ; leaves broader than in the foregoing, and 

 white with silky down ; flowers large and white. More or less 

 frequent in the Highlands of Scotland, and occasional in the north 

 of England. — Fl. summer. Perennial. 



4. C. tris,yniim (Starwort Mouse-ear Chickweed). — A rare form 

 found on the Breadalbane and other mountains in Scotland. Stems 

 slender, ascending, about 6 inches long, with a line of hairs on 

 alternate sides between each pair of leaves ; otherwise the plant is 

 usually glabrous ; leaves narrow ; teeth of the seed-vessel twice as 

 many as the styles ; styles usually 3, occasionaUy 4-6. — Fl. July, 

 August. 



Cerastiuii 



\'UtG.\TUM 



{TJousL'-cai Chick- 

 weed) 



Natural Order XV 



LTNACE.E.— The Flax Tribe 



Sepals 3-5, overlapping when in bud, persistent ; petals equal in 

 Iiumber to the sepals, twisted when in bud, falling off very soon 



