204 COMPOSITE. 



tier involucre closes for a time, the slender beak elongates and raises up the pappui 

 while the fruit is forming, the whole involucre is then reflexed, exposing to tha 

 •wind the naked seeds with the pappus displayed in an open globular form. Th# 

 leaves are used in spring as a pot-herb. 



67. LACTUCA, Tourn. Lettuce. 



The ancient name of Lettuce, from lac, milk in allusion to the milky juice. 



HEAD9»several-flowered. Involucre cylindric ; Scales 

 imbricated in 2 or more sets of unequal lengths. Recepta- 

 cle naked. Achenia flat, obconapressed, abruptly pro- 

 duced into a long thread-like beak. Pa ■.. B of very soft 

 and white capillary bristles. — Leafy-stemed herbs, withpani- 

 cltd heads of various-colored flowers. 



1. L. elongata, Muhl. Wild Lettuce. 



Stem tall and stout; leaves partly clasping, pale beneath; the upper lanceolate 

 and entire ; the lower runcinate-pinnatifid; heads in a long and narrow panicle, 

 varies greatly. The var. integrifblia is mostly smooth, with the leaves nearly all 

 entire and the flowers yellow or bluish. Var. sungmnoi is smaller, mostly hairy ^ 

 with the leaves chiefly runcinate, and the flowers variously colored. Gr. 



Rich damp soil, hedges and thickets, common. July — Sept., Biennial. Stem 2 to 

 8 feet high, often purple, bearing a leafless, elongated, sometimes corymbes ^-spread- 

 ing panicle of numerous heads of flowers. CaroUes yellow. Achenia oblong, coia- 

 pressed, about the length of the beak. 



2. sativa, L. Garden Lettuce. Sallad. 



Stem corymbose ; leaves suborbicular, those of the stem coraate. A well known 

 cultivated exotic, with several varieties. The var. capitata has the leaves so thick at 

 to firm heads like the cabbage. Heads numerous, small, with yellowish caroilaa. 

 The milky juice contains opium. 



63. MULGEDIUM, Cass. 



Lat mulgco, to milk. 



Heads many-flowered. Involucre calyculate-imbricate, 

 the outer scales much shorter than the' inner. Receptacle 

 naked, honey-combed. Achenia smooth, compressed, at- 

 tenuated in a beak at the summit, appearing as if a part of 

 the achenia, and expanded at the apex into a ciliate disk, 

 which bears copious pappus of soft capillary bristles. — Leafy- 

 stemmed herbs, with panicledor racemed heads of chiefly blue flower*. 



1. M. ACUMINATUM, DC. Sharp-leaved Mulgedium. 



Smooth; stem panicled above; stem-leaves ovate and ovate-lanceolate, pointed 

 merely toothed, sometimes hairy on the midrib beneath, contracted at the baaa 

 into a winged petiole; the lower ones sometimes runcinate or sinuate; heads in m 

 thyrse-like panicle ; peduncles somewhat scaly. 



Borders of thickets and shady woods. Aug.— Sept., Biennial. Stem 3 to 6 fat 

 high, erect, smooth, simple. Leaves 3 to 6 iuches long, the lower ones often deltoid- 

 hastate or truncate at the baie, narrowed into a winged petiole. Heads small, not 

 numerous, in a widely spreading terminal panicle. ScaUt dark purple. Cbrolim 



Mm 



