74 LETTUCE. 



alternate, roundish-oblong, rugose, toothed and undulated at the 

 margin, and of a shining light-green colour; the lowermost 

 spreading, the cauline ones smaller, amplexicaul, cordate, acute. 

 The flowers form a large, spreading leafy corymb at the top of the 

 stem. The involucre consists of several imbricated scales, or brac- 

 teae, unequal, flat, acute, and membranous at the margin. The 

 corolla? are yellow, numerous, in several rows, perfect, equal, 

 ligulate, abrupt, with four or five teelh. The five filaments are 

 capillary, and very short, with the anthers united into a tube. The 

 germen is ovate, or oblong, surmounted by a filiform style, rather 

 longer than the stamens, and tipped with two reflexed stigmas. 

 The fruit is an ovate-elliptical pericarp or akenium, furrowed and 

 compressed, surmounted with the stipitate pappus. The receptacle 

 is naked and dotted. Plate 29, fig. 4, (a) involucre magnified ; 

 (h) entire flower or floret; (c) the ripe fruit crowned with the pappus. 



The cultivated Lettuce, with its numberless varieties, is familiar 

 to every one ; but it has been so metamorphosed by the skill and 

 industry of man, that its origin is unknown. Many botanists con- 

 sider the strong-scented Lettuce (L. virosa) as the parent species. 

 The flowers appear in July; they expand only on bright sunny 

 mornings, and close at the approach of rain. 



The generic term is derived from lac , milk, in allusion to the milky 

 juice which exudes from the wounded stem. There is every reason 

 to think that the Lettuce is the Qptiag of Dioscorides,* and of 

 Theophrastus.f 



There are three species of Lettuce natives of Britain ; the 

 strong-scented (L. virosa), with spreading, oblong, toothed, am- 

 plexicaul leaves, which are prickly underneath at the midrib, and 

 .panicled flowers. It grows on banks, and by way-sides, in a chalky 

 soil, and flowers in August. The prickly Lettuce {L. scariola) 

 known by its upright, lanceolate, saggitate, pale-coloured leaves. 

 The least Lettuce (L. saligna) is a slender plant, with lanceolate 

 radical leaves, and linear-saggitate cauline ones ; besides which, its 

 flowers are lateral and almost spicate. It grows in chalky waste 

 ground, near salt marshes, in the south-east of England. 



Qualities and general Uses. — The Lettuce was much es- 

 teemed as a salad by the Romans. A prejudice, however, was for 



* Mat. Med. lib. ii. c. lfo. 

 f Hist. lib. vii. c. 3. 



