Part 2, 1915] CARDUACEAE : HEL/ENIEAE 101 



59. PLATEILEMA (A. Gray) Cockerell, Bull. Torrey Club 31: 462. 



1904. 



Actinella § Plateilema A. Gray. Proc. Am. Acad. 1Q: 31. 1883. 



Depressed suhscapose perennials, with a multieipital cespitose rootstock. Leaves alter" 

 nate, crowded at the base, pinnately Lobed. Heads radiate, on short scapes. Involucre turbi- 

 nate; bracts 10-12, in two equal series, broad, thick and rounded on tin- back, all united at the 

 base. Receptacle convex. Ray-flowers 10-12, pistillate, fertile; ligules oblong-cuneate, 3-lobed, 

 strongly 4-nerved. Disk-flowers hermaphrodite and fertile; corolla-tube glabrous, much shorter 

 than the campanulate-cyliudric glandular-puberulent throat; lobes 5, glandular-hispidulous. 

 Style-branches truncate. Achenes elongate-obpyramidal, 4-5-angled, striate, hirsute but 

 not densely so. Pappus of 4 or 5 oblong, truncate, erose, chartaceous-scarious, not nerved 

 squarnellae. 



Type species, Actinella Palmeri A. Gray. 



1. Plateilema Palmeri (A. Gray) Cockerell, Bull. Torrcv Club 31: 



462. 1904. 



Actinella Palmeri A. Gray, Proc. Am. Acad. 19: 31. 1883. 



A depressed subscapose perennial, with a cespitose rootstock; leaves obovate in outline, 



4-5 cm. long, pinnately round-lobed, firm, resembling oak-leaves, very sparingly hispid or 



glabrate; scape 2-4 cm. long; involucre about 8 mm. high and 15 mm. broad, sparingly his- 



pidulous, especially on the margins; bracts broadly ovate, acute, with spreading tips; ligules 



7-8 mm. long, 2-3 mm. wide; disk-corollas 3.5 mm. long; achenes 3 mm. long, less than 



1 mm. broad; squarnellae 2 mm. long, brown. 



Type locality: Near Saltillo. Coahuila. 

 Distribution: State of Coahuila. 



60. TETRANEURIS Greene, Pittonia 3: 265. 1898. 



Actinella Nutt. Gen. 2: 173, in part. 1818. Not Actinella Pers. 1807. 



Perennial or annual, caulescent or scapose, more or less villous or silky herbs. Leaves 

 usually entire, rarely some of them lobed, alternate, either clustered at the base, or scattered 

 along the stem, or both. Heads radiate, rarely discoid, on slender peduncles. Involucre 

 hemispheric, or nearly so; bracts several in two subequal series, distinct, densely villous or 

 silky. Receptacle convex, naked. Ray-flowers 10-20, pistillate and fertile; ligules yellow, 

 oblong, broad, 3- (rarely 4-) toothed, usually somewhat pubescent at least below; nerves 4, 

 rarely more, with the branches connecting in the teeth. Disk-flowers many, hermaphrodite 

 and fertile; corollas with a very short tube, an elongate almost tubular or slightly funnelform 

 throat, and 5 short pubescent lobes. Anther-tips broad, triangular or ovate. Style-branches 

 dilated-truncate, somewhat penicillate at the tips. Achenes obpyramidal, 5-angled, about 3 

 times as long as broad, densely hirsute. Pappus of about 5 hyaline squarnellae, with a strong 

 midrib, which sometimes is produced into an awn. 



Type species, Gaillardia acaidis Pursh. 



Perennials, with a cespitose rootstock or caudex. 

 Heads sessile among the leaves. 



Plant villous; rays longer than the involucre. 1. T. depressa. 



Plant densely sericeous; rays not exceeding the involucre. 2. T. pygmaea. 



Heads distinctly peduncled. 



Stems scapiform, leafy only at the base. 

 Leaves appressed-silky. 



Leaves not strongly 3-nerved on the broadened bases 



Leaves spatulate or oblanceolate, 2-4 cm. long; scape 



stout, 5-10 cm. high. 3. T. septentrionalis, 



Leaves linear or linear-oblanceolate; scape 10-20 cm. high. 



Leaves silvery-silky; ligules 6-8 mm. long. 4. T. acaulis. 



Leaves greenish, sparingly silky; ligules 8-10 mm. long. 5. T. simplex. 

 Leaves strongly 3-nerved on the broadened bases, narrowly 



linear-oblanceolate. 6. T. trineriaia. 



Leaves loosely villous or glabrate. 



Leaves, scape, and involucre decidedly villous. 



Ligules 10-15 mm. long, conspicuously veined; plant not 



conspicuously cespitose, forming small tufts. 7. T. scaposa, 



