986 COMPOSITE. [Lactuca. 



XXXIX. Lactuca, Linn. Lettuce. 



" Achenes much compressed, with a long beak. Pappus pilose. 

 Receptacle naked. Involucre imbricated, cylindrical, few-flowered, 

 its scales with a membranous margin." — Br. Fl. 



1. Tu. muralis, DC. Ivy-leaved Lettuce. Wall Lettuce. "Flo- 

 rets 5, leaves lyrate-pinnatifid and toothed, the terminal lobe 

 angled, panicle with divaricated branches, beak much shorter 

 than the (black) achene." — Br. Fl. p. 205. Prenanthes, L. : E. 

 B. t. 457. 



On old walls, rooks, moist sliady bants, woods and tliickels, but not common. 

 Fl. June — August. 2^. 



JS. Med. — On the walls of Quarr abbey, but sparingly. In Church lane. Bin- 

 stead, several plants. Bather plentiful under the garden-wall at Knighton house. 

 Frequent under the rooks at Hatchet close and Cowpit-cliff woods, near ShanMin. 

 In Bloodstone copse, in several places. [Side of a path leading from Brading to 

 the down, A. G. More, Esq., Edrs.] 



W. Med. — Woods about Rowledge, and in Westover plantation, occasionally. 

 On a bank by the roadside near Apes down, in some plenty. Copse near Buc- 

 combe down. Sluccombe copse, a little W. of Roughborough. In some plenty 

 in the little copse above Alvington marl-pit. 



A slender, smooth, latesceut herb. Root short and fleshy, emitting several long 

 slender fibres. Stem about 1 — 3 feet in height, mostly solitary, more rarely 2 or 

 3 from the same root, erect, leafy, round, smooth, slightly flexuose, simple, hollow 

 or filled with white cellular tissue, green or purplish. Leaves alternate, rather 

 remote, thin and membranous, flat, bright pale green, whitish or glaucous beneath, 

 and often tinged with violet, strongly veined, lyrato-runcinate, lower ones on long 

 winged petioles, those higher up broader, dilated, rounded and clasping at the 

 base, the auricles toothed, acute and in the superior leaves almost sagittate, their 

 points often deflexed ; uppei-most leaves sometimes oblong and nearly entire, the 

 rest with acutely angular, sinuate and toothed lobes, the terminal one of which is 

 very large, more or less distinctly trilobate and resembling an ivy-leaf in shape, 

 its central division much produced, and like the lateral sharply angulato-dentate, 

 mucronato-acuminate. PaBJc/e terminal, of several alternate, patent or spreading, 

 divaricately ramifying branches. Flowers small, erect, bright yellow, their pedi- 

 cels with one or two small clasping bracts. Involucre slender, cylindrical, its 

 outer scales very small, unequal, mostly 3, shaped like those on the pedicels and 

 at the forks of the panicle ; inner 5, nearly equal, linear-oblong, obtuse and cili- 

 ated at the summit, with pale membranous edges, scarcely keeled, blackish or 

 purplish, green at the back, strongly reflexed in seed. Florets 5, the tube very 

 slender, and hairy near the top ; ray broad, ovate-truncate, 5-toothed and striate. 

 Styles rough in their upper part, 2-cleft, the segments linear, revolute. Achmium 

 obovato-oblong, much compressed, dark brown, roughish with very short minute 

 pubescence, each face with se\ eral (5 or 6) obtuse ridges. Pappus single-rowed, ? 

 snow-white, roughish, placed on a circular disk, which is downy on the margin 

 and stipitate on the very short beak, which is scarcely Jth the length of the seed. 



3. L. virosa, L. Strong-scented Lettuce. " Leaves patent ob- 

 long toothed or sinuated two-eared and amplexjcaul at the base, 

 flowers panicled, beak as long as the (black) achene." — Br. Fl. p. 

 304. E. B. t. 1957. 



On hedgebanks, old walls, cliffs, and borders of fields, mostly on a chalky soil ; 

 very rare. FL July? — September. $. 



JE. Med. — On a hedgebank between Wroxall and Newchurch, 1844, Miss 

 Hadfield ! 



