240 COMPOSITE. [TARAXACUM. 



imbricate ; inner equal, erect ; outer often recurved ; receptacle flat, naked, 

 pitted. Corollas all ligulate, yellow ; anther- cells not tailed ; style-arms 

 slender and upper part of style pubescent. Fruit compressed, ribbed, 

 muricate above the middle, abruptly beaked ; pappus-hairs in many series, 

 simple, white. DISTRIB. All temp, and cold climates ; species about 

 6. ETYM. rapao-o-co, from its alterative effects. 



T. officina'le, Web. leaves toothed sinuate or runcinate-pinnatifid. 

 Leon'todon Tarax'acum, L. 



Meadows and waste places, N. to Shetland ; Ireland ; Channel Islands ; 

 fl. March-Oct. Glabrous, or cottony at the crown and involucre. Root 

 long, stout, black. Leaves oblong-obovate or spathnlate, lobes usually 

 toothed. Scapes 1 or more, ascending or erect. Head ^-2 in. broad, bud 

 erect; involucre campanulate, outer bracts more or less recurved, inner 

 erect. Corollas bright yellow, outer often brown on the back. Fruit brown, 

 with a beak of equal length. DISTRIB. Arctic and N. and S. temp, 

 regions. A well-known medicine. 



T. ojficina'le proper ( T. Dens-leo'nis, Desf.) ; leaves bright green runcinate-pin- 

 natifid, outer bracts recurved, fruit pale. The common form in cultivated 

 ground ; ascends to 2,700 ft. in the Highlands. VAR. T. en/throsper'mum, 

 Andrz. ; leaves dull green often glaucous runcinate-pinnatifid, outer bracts 

 spreading, inner appendiculate below the tip, fruit dark brown. Dry places. 

 YAR. T. laviya'tum, DC. ; leaves dull green pinnatifid, outer bracts erect 

 broader, inner appendiculate or gibbous below the tip, pale. Sandy places. 

 VAR. T. palus'tre, DC. ; leaves sinuate-toothed or pinnatifid, lobes broad, 

 outer bracts ovate spreading or erect, inner simple at the tip, fruit pale. 

 Moist moorlands ; ascends to 4,000 ft. in the Highlands. 



40. LACTU'CA, L. LETTUCE. 



Erect, annual or perennial, leafy, branched herbs ; juice milky. Leaves 

 alternate, upper often sagittate. Heads corymbose, small, few-fld. ; in- 

 volucre narrow, cylindric ; bracts few, in several series ; receptacle flat, 

 naked. Corollas all ligulate, yellow, purple or blue ; anther-cells shortly 

 tailed ; style-arms slender and upper part of style hairy. Fruit flattened 

 terete or angled, beak short or long slender ; pappus of many soft, slender, 

 silvery, fugacious hairs. DISTRIB. N . temp, regions, S. Africa ; species 

 about 60. ETYM. The classical name. 



* Leaves with the keel usually bristly. Beak as long as the bordered fruit. 

 1. L. viro'sa, L. ; sparsely scabrous, leaves spreading, radical obovate- 



oblong sinuate- toothed, cauline amplexicaul with deflexed auricles, branches 



of panicle long spreading, fruit black. 



Hedgebanks and waste places, from Perth and Ayr southd. ; rare in Scotland ; 

 Channel Islands ; fl. July- Aug. Erect, 3-6 ft., prickly, glaucous, biennial. 

 Leaves 6-18 in., radical petioled, often spotted with black ; cauline oblong, 

 hardly narrowed at the base. Heads |-| in., pale yellow, in slender panicles, 

 subsecund ; peduncles slender, bracteate ; involucre narrow, conical ; bracts 

 few, green, tips red. Fruit with a thick cellular wing and ribbed faces. 



