COMPOSITE FAMILY 293 



ally with a long, slender beak; pappus of many simple hairs. 

 (Name of Classical origin, referring to the milky juice.) 



1. L. virosa (Acrid Lettuce). — An acrid, glaucous, prickly plant, 

 2 — 4 feet high ; leaves spreading horizontally, with bristles along 

 the mid-rib beneath, the lower ones often spotted with black, the 

 upper ones clasping, with downward-pointing auricles ; heads 

 small, pale yellow, in a loose, slender spreading panicle ; fruit 

 black. — Dry banks ; not uncommon. — Fl. July, August. Biennial. 



2. L. Serriola (Prickly Lettuce). — A closely allied species, less 

 prickly, with more erect branches and leaves, the upper leaves 

 sagittate and clasping, grey fruit and a less acrid juice. — Waste 

 places ; rare. This may be the origin of the Garden Lettuce 

 (L. sativa). — Fl. July, August. Biennial. 



3. L. saligna. — A slender, less bristly, almost glabrous plant, 

 with upper leaves linear, entire, acuminate, hastate at the base, and 

 heads in lateral tufted clusters. — Chalky places in the south-east, 

 especially near the sea ; rare. — Fl. July, August. Biennial. 



4. L. murdlis (Ivy-leaved Lettuce). — A slender, glabrous plant, 

 I — 2 feet high, leafy below ; stem round, hollow ; leaves lyrately 

 pinnatifid, variously cut, glaucous beneath, auricled ; heads small, 

 yellow, in a slender, angular, spreading panicle, each containing 

 5 florets, and so resembling a flower with 5 petals ; fruit black. — 

 Old walls and woods; not uncommon. —Fl. June — September. 

 Biennial. 



47. MuLGEDiUM (Blue Sow-thistle).— A succulent plant with 

 milky juice, unbranched ; leaves cauline, diminishing upwards ; 

 heads numerous, in a raceme, blue ; bracts imbricate, the outer 

 shorter, lax ; receptacle flat, naked ; fruit 4-angled, not beaked 

 but^narrowed above and ending in a ciliate disk ; outer hairs of 

 pappus rigid, turning brown, brittle. (Name from the Latin 

 mulgeo, I milk, referring to the juice.) 



I. M. alpinum (Blue Sow-thistle). — A very handsome plant, 

 about 3 feet high, succulent, unbranched, and leafy, with pale 

 blue heads, i in. across, in a raceme, grows on the Clova mountains, 

 but is rare. 



48. SoNCHUS (Sow-thistle). — Herbs with milky juice, generally 

 succulent ; leaves scattered, toothed or pinnatifid ; heads yellow, 

 in corymbs ; bracts imbricate in several rows ; receptacle flat, 

 naked, pitted ; fruit much flattened, not beaked ; pappus of 

 many rows of white, simple, silky hairs. (Name of Greek origin, 

 said to refer to its juice being wholesome ; but this is doubtful.) 



I. ^. olerdceus (Common Sow-thistle, Milk-thistle). — Usually 

 glabrous, 2 — ^3 feet high, erect, branched ; stem hollow ; leaves 



