23 THALAM I FLORAE 



from the use of fresh vegetables. Many other 

 plants of the same tribe possess antiscorbutic pre 

 perties to an equal degree, but these are particu- 

 larly available from always growing near the sea 

 The use of lime-juice in the navy and merchant 

 service has rendered the attacks of this disease less 

 frequent than they used to be. 



8. Subularia (Awl-wort) 



i. S. aquatica (Water Awl-wort). The only 

 species. The roots are composed of long white 

 fibres ; the leaves all grow from the roots, and 

 are awl-shaped ; the flowers are small and few ; 

 Subularia petals white. The plant often grows entirely 

 Aquatica {Water under water ; common on the banks of Alpine 

 Awl-wort) lakes. Fl. July. Annual. 



g. Alyssum (Alyssum) 



i. A. calycinum (Small Alyssum). A small annual, 3-6 inches 

 high. Flowers pale yellow ; sepals persistent, or remaining on the 

 pods. Waste places, rare. Fl. April to June. 



2. A. maritimum (Sweet Alyssum). A pretty garden plant, with 

 trailing ascending stems and white, sweet-scented flowers ; sepals 

 falling off. In many places it has become established as a garden 

 escape. Fl. all summer. Annual or perennial. 



10. Draba (Whitlow Grass) 



1. D. aizoides (Yellow Alpine Whitlow Grass). Flower-stalk 

 leafless, smooth ; petals notched, twice as long as the calyx ; style 

 much longer than the stamens ; leaves narrow, pointed, rigid, 

 glossy, keeled, and fringed. On rocks and walls at Pannard Castle, 

 near Swansea, where it forms dense tufts, conspicuous with bright 

 yellow flowers. Fl. March, April. Perennial. 



2. D. rupestris (Rock Whitlow Grass). A very rare species 

 growing in the crevices of the rocks and among moss, on the summits 

 of some of the Highland mountains. It seldom exceeds 2 inches 

 in height ; the flower-stems are usually leafless, several growing 

 from the same root ; the leaves grow in tufts and are slightly 

 hairy. Fl. July. Perennial. 



3. D. incana (Twisted Whitlow Grass). Stems 4-12 inches high, 

 bearing small white flowers ; stem-leaves narrow, toothed, hoary ; 

 petals entire ; pouch twisted. Remarkable for the down on its 

 leaves, which is forked in a starlike manner. Mountains and 

 sand ^unes on the coast, scarce. Fl. June, July. Biennial. 



