249 
achenes, the apex prolonged into a very slender beak which bears the 
copious soft and white capillary pappus. 
1. T. officinale Weber. Smooth, or at first pubescent: outer involucre reflexed. 
(T. Dens-leonis Desf.)—Common everywhere, an introduction from Europe. The 
pappus, finally displayed in an open globular head, is familiar to all. 
125. PYRRHOPAPPUS DC. (FALSE DANDELION.) 
Mostly annual or biennial herbs scapose or often branching and leafy 
below, with solitary heads of deep yellow flowers terminating the naked 
summit of stem or branches, heads, ete., like Taraxacum, except the 
soft pappus is reddish or rusty-color and surrounded at base by a soft- 
villous ring. 
* Scapose and with solitary head. 
1. P. scaposus DC. Low and simple perennial by roundish tubers: leaves all 
radical and pinnatifid.—Extending from the plains of Arkansas and Kansas to those 
of Texas. 
* * More or less leafy-slemmed and branching. 
2. P. Carolinianus DC. Annual or biennial, freely branching, 6 to 15 dm. high: 
leaves oblong or lanceolate, entire, cut or pinnatifid, those of the stem partly clasp- 
ing: fruiting heads fully 25 mm. high: calyculate involueral bracts loose, half or a 
third the length of the principal ones. —Extending from the Gulf States into Texas, 
8. P. multicaulis DC. Lower, from a thickened apparently perennial root, less 
leafy, at length many-stemmed from base and diffuse or ascending: fruiting heads 
16 to 18 mm. high: calyculate involucral bracts short.—Throughout southern Texas 
and adjacent Mexico. 
126. LACTUCA Tourn. (LETTUCE.) 
Leafy-stemmed herbs, with panicled heads of variously colored 
flowers, cylindrical or conical imbricated involucre of 2 or more sets of 
bracts of unequal length, and flat achenes abruptly contracted into a 
beak which 1s dilated at apex and bears a copious fugacious very soft 
and white capillary pappus (its bristles falling separately). 
* Achenes very flat, orbicular to oblong, with a filiform beak: stem-leaves sagittate- 
clasping. 
1. L. hirsuta Muhl. Rather few-leaved, 6 to 9 dm. high, commonly hirsute at 
base: leaves hirsute on both sides or only on the midrib, mostly runcinate-pinnatifid : 
heads in a loose open panicle: achenes oblong-oval, about as long as the beak: 
flowers yellow-purple, rarely whitish. (1. Canadensis var. sanguinea Torr. & Gray.)— 
Dry and open ground, extending from the Atlantic States into Texas, at least as far 
west as Gillespie County (Jermy). 
2, L. graminifolia Michx. Stem slender, 6 to 9 dm. high, terminating in a naked 
loose panicle: glaucescent and glabrous, or merely hispid on the midrib beneath, or 
hirsute as in the last: leaves elongated-linear or linear-lanceolate (10 to 30 cm. long), 
entire or with spreading or deflexed lobes, or the radical pinnatifid: achenes ellip- 
tical-oblong, longer than the beak: flowers purple or pale blue (varying to white or 
yellow).—Dry and fertile soil, extending from the Gulf States through Texas to 
Arizona, 
3. L. Ludoviciana DC. Glabrous, leafy, 6 to 15 dm. high: leaves oblong, sin- 
uate-pinnatifid and spinulosely dentate, ciliate: heads in an open panicle: involu- 
cre more imbricate: achenes oblong-oval, about equaling the beak: flowers yellow.— 
Along the Limpia (Bigelow). 
