308 SYNGENESIA POLYGAMIA ^QUALIS. [CL. XIX- 



roughish, compressed ; seed-down liair-like, stalked. Recep- 

 tacle naked, dotted. Name, from lac, milk, on account of its 

 white juice. 369. 



1. L. virosa. Strong-scented Lettuce. Leaves horizontal, toothed ; 



their keel prickly. Stem two or three feet high, erect, round, 



smooth : root-leaves numerous, inversely egg-shaped, stem-leaves 

 smaller, frequently lobed, arrow-shaped and embracing at the base : 

 flowers numerous, pale-yellow, panic-led. The whole plant abounds 

 with an acrid milky juice, having the narcotic properties of opium. 

 Biennial : flowers in August and September : grows in borders of 

 fields and about hedges and old walls : frequent in England, rare 

 in Scotland. Eng. Bot. vol. xxviii. pi. 1957. Eng. FL vol. iii. p. 345. 



1113. 



2. L. Scariola. Prickly Lettuce. Leaves perpendicular, sinuated ; 



finely toothed, their keel prickly. Stem two or three feet high, 



erect, panicled : leaves variously pinnatifid and sinuate : flowers 

 pale-yellow. It abounds in acrid milky fluid like the last. Pe- 

 rennial : flowers in August : grows in waste ground and the borders 

 of fields, in Essex and Cambridge. Eng. Bot. -vol. iv. pi. 268. Eng. 

 FL vol. iii. p. 346. 1114. 



3. L.saligna. Least Lettuce. Leaves linear, halbert-shaped, sessile, 



their keel prickly. Stem two feet high, waved : leaves embracing 



the stem : flowers pale-yellow : milky. Biennial : flowers in Au- 

 gust : grows in waste ground near salt marshes, in the south-east 

 of England : rare. Eng. Bot. vol. x. pi. 707. Eng. Fl. vol. iii. p. 347. 



1115. 



5. PRENA'NTHES. WALL-LETTUCE. 



Common calyx cylindrical, double ; the inner of as many 

 linear, equal scales as there are florets ; the outer of a few, very 

 short, unequal scales. Compound corolla of a single row of 

 perfect, equal, strap-shaped, abrupt, four or five -toothed florets. 

 Filaments five, hair-like, very short; anthers united into a 

 slender cylindrical tube. Germens oblong. Style hair-like, 

 longer than the stamens ; stigmas two, revolute. Seeds oblong, 

 furrowed : seed-down hair-like, roughish, sessile. Receptacle 

 naked, very narrow. Name, fromprenes, drooping, audanthos, 

 a flower. " 370. 



1. P.murdlis. Ivy -leaved Wall Lettuce. Florets five ; leaves run- 



cinate. Stem afoot high, round, hollow, panicled above : leaves 



embracing the stem : flowers erect, bright- yellow, with a purplish 

 calyx. Perennial : flowers in July : grows on old walls and rocks : 

 common. Eng. Bot. vol. vii. pi. 457. Eng. Fl. vol. iii. p. 348. 1116. 



6. LEO'NTODON. DANDELION. 



Common calyx oblong, double ; the inner of several linear, 

 equal, parallel scales ; the outer of fewer and shorter ones. Com- 

 pound corolla of very numerous, imbricated, equal, perfect, strap- 

 shaped, abrupt, five-toothed florets. Filaments hair-like, short; 

 anthers united into a cylindrical tube. Germeu inversely egg- 

 shaped, furrowed. Style cylindrical, longer than the stamens ; 

 stigmas two, revolute. Seed inversely egg-shaped, furrowed ; 

 seed-down in hair-like rays, on a long cylindrical stalk. Recep- 



