Lactuca.] lxxiii. compositjb (oliyer and hiern). 461 



sagittate; auricles acute or shortly setaceous-acuminate. Achenes 

 oval or olDlong, all similar, more or less compressed, narrowed at the 

 base, terminating in a short beak or long neck, 4-10-costate. Pappus 

 copiously setose, in many rows, persistent or deciduous in one piece. — 

 Herbs, usually glabrous, with milky sap, alternate or radical leaves 

 and yellow or blue flowers. 



A considerable genus, widely spread over the Old World and North America. 

 The lettuce, L. sativa, Linn., is cultivated in Nubia, Cordofan and Abyssinia. 

 L. albiflora, Schultz Bip. in Schweiuf. and Aschers. Enum. 285, from 8ennaar, is 

 unknown to us. 



Achenes fusiform, about lO-costate, tapering to a short beak 

 {Brach^rkampkus). 



Inner involucral bracts 5 1 . Z. taraxacifolia. 



Inner involucral bracts 8 2: L. goraensis. 



Achenes compressed, with thickened margin, 1 central vein 



on each side, and very short beak 3. L. Schweinfurthii. 



Achenes compressed, terminating in a long slender neck 

 {Scariola). 

 Achenes 1-ribbed on each side. 



Stem somewhat flexuous 4. Z. capensis. 



Stem straight rigid 5. i. abyssinica. 



Achenes with several ribs on each side. 

 Habit erect or ascending, not scandent. 



Inflorescence elongated. Pappus white. Usually 



somewhat setose-scabrid 6. X. virosa. 



Inflorescence diffuse or short. Pappus yellowish. 

 Usually smooth. 



Heads numerous T. L. Hochstetteri. 



Heads fewer, distant 8. i. rariflora. 



Habit scandent. 



Nearly glabrous 9. i. paradoxa. 



Hispid-glandular 10. L. glandulifera. 



1. Ii. tarazacifolla, Schum. Sf Thonn. Beshr. Guin. PI. p. 380. 

 Root simple. Stem erect, glabrous, terete, glaucescent, unarmed, 2-6 

 ft. high, simple below, with a cluster of leaves at the base. Leaves 

 runcinate, the upper rather acute, the lower rather obtuse, glabrous or 

 nearly so, ranging up to more than 6 by 4 in. ; stem-leaves sessile, am- 

 plexicaul, the lowest ones narrowed into a short winged petiole ; lobes 

 variable in breadth and depth, denticulate ; teeth usually callous, acute, 

 like small prickles. Capitula about 20-flowered, f-J in. long, on very 

 short pedicels, in panicled racemose cymes. Inner involucral bracts 

 5, obtuse, linear-oblong ; outer bracts imbricated, ovate, obtusely 

 pointed, with scarious margins, varying up to about half the 

 length of the inner ones. Achenes dark, about 10-costate longitudi- 

 nally, transversely rugulose, fusiform, ^-^^ in. long, tapering to a 

 short slender pale apex. Pappus I in. long, nearly white. — DC. Prodr. 

 vii. p. 138. Schultz Bip. in Flora 1842, p. 422. Sonchus taraxacifoUus, 

 Willd. Sp. PI. iii. p. 1511. S. sei-ratus, Perr. ex DC. 1. c. Microrhyn- 

 chus pentaphylluSy Hochst. in Herb. Kotsch. Nub. n. 337. L. penta- 

 phylla, Schultz Bip. and L. Kotschyi, Schultz Bip. in Linnsea xv. p. 

 725 (1841). S. pentaphyllusj Schultz Bip. in Schweinf. Beitr. Fl 

 wSlthiop. p. 160, 



