234 DICOTYLEDONS. — coMPOsiTiE. Lactuca. 



regular or irregular, its divisions edged with a nerve. Stame?is 

 5, syngenesious. Ovary one. Siyle one, sheathed by the tube 

 of the anthers. Stigma simple or bifid. Fruil an achenium. 

 Seed erect, without albumen. Embryo straight. Radicle oppo- 

 site the hilum. 

 Stems (in the British genera) herbaceous. Leaves opposite or 

 alternate. Floicers capitate, inserted into a broad receptacle 

 and surrounded by an involucre. 



Div. I. CiCHORACEiE. Jlll thejlorets ligulate and perfect. 

 l.TRAGOPOGON. 



Invohtcre simple, of many leaves. Receptacle naked. Pappus 

 feathery, stipitate. Pericarps longitudinally striated. 



1. Tr. pratensis, involucre about as long as the cor., leaves un- 

 divided glabrous acuminated channelledj peduncles cylindrical. 

 p. 226. -^Pastures. 



2. Tr. porriJbHus, involucre much longer than the cor., leaves 

 undivided straight, peduncle thickened upwards, p. 226. — 

 Meadow Sy rare. 



2. PICRIS. 



Cal. double, the inner segments equal, the outer lax. Receptacle 

 naked. Pappus feathery. Pericarps transversely striated. 

 [Picris and Helminthia, Decand.) 



1. P. hieracioides, exterior scales of the involucre short lax, leaves 

 very rough lanceolate toothed, stem scabrous, pappus sessile. 

 p. 226. — Road-sides. 



3. SONCHUS. 



Involucre imbricated, swelling at the base. Receptacle naked. 

 Pappus simple, sessile. 



1. S. ccerule2ts, " peduncles and involucre hispid racemose, leaves 

 sublyrate, terminal lobe deltoid very large," Sni.p.226. — Alps. 



2. S. arvensis, peduncles and involucre hispid subumbellate, leaves 

 runcinate dentato-ciliate cordate at the base. p. 226. — Corn- 



Jields. 



3. S. oleraceus, peduncles subtomcntose umbellate, involucre 

 glabrous, leaves runcinate dentato-ciliate amplexicaul at the 

 base. p. 227. — Waste places. 



4. LACTUCA. 



Involucre imbricated, cylindrical ; its scales with a membranous 

 margin. Receptacle naked. Pappus simple, stipitate. 



1. L. virosa, leaves oblong toothed horizontal, their keel prickly, 



their apex obtuse, p. 227. — Banks, rare. 



