SPECIES AND VARIETIES. 275 



(174) Helminthia. Ox-tongue. 



H. echioides: annual or biennial; stem coarse, erect, 1-3 feet 

 high, rough with short, stiff, almost prickly, often hooked hairs ; 

 leaves lanceolate, sinuate or coarsely-toothed, rough, the upper 

 ones clasping the stem, or shortly decurrent; flower-heads 

 small, crowded, on short peduncles, forming an irregular ter- 

 minal corymb. — Hedge-banks, fields, and waste places. — Fl. 

 July to September. 



(175) Tragopogon. Salsify. 



T. pratense : stem erect, slightly branched, 1-2 feet high ; 

 radical and lower leaves linear, keeled, dilated at the base, 

 glabrous, slightly glaucous ; peduncles long, thickened at the 

 summit, each with a single head of yellow flowers ; involucral 

 bracts narrow-lanceolate; florets sometimes not half as long; 

 achenes long, striate, the slender beak as long as the achene 

 itself, the hairs of the pappus long and very feathery. — Yellow 

 Goat's-beard. — Meadows and rich pastures. Fl. June. 



T. porrifolium resembles the last, but is generally of more 

 luxuriant growth, the peduncles more thickened at the top, the 

 involucres longer in proportion to the florets, and the beak of 

 the achenes and pappus longer. It also has deep violet or 

 purple flowers. 



(176) Lactuca. Lettuce. 



* Leaves smootJi-Tceeled, on long stalks. 



L. muralis : annual or biennial ; stems glabrous, erect, two 

 feet high, with slender branches, forming a loose terminal 

 panicle ; leaves few, thin, rather large, with a broadly- trian- 

 gular, toothed or lobed terminal segment, and a few irregular 

 smaller ones below, the upper ones small, narrow, entire or 



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