190 NORTH AMERICAN FLORA [VoLUME 34 
1 cm. high and 7 mm. broad; bracts oblong, with triangular acute tips, dark-purple and often 
glaucous, with 2 rows of linear glands; corollas purple, puberulent, 6 mm. long; tube longer 
than the elongate-funnelform throat; lobes narrowly lanceolate; achenes 6 mm. long, hispidu- 
lous; pappus tinged with purple, 6 mm. long; bristles hispidulous. 
TYPE LOCALITY: Mexico. 
DIstTRIBUTION: Coahuila to siete of Mexico. 
ILLUSTRATION: Cav. Ic. pl. 
26. Porophyllum Seemannii Schultz-Bip.; Seem. Bot. Voy. Herald 
308. 1857. 
A fruticose perennial, glabrous; stem terete, striate, reddish-brown; branchlets green; 
leaves alternate or opposite, subsessile; blades linear-oblanceolate, 2-5 cm. long, 4-8 mm. wide, 
acute or obtuse, with 3 or 4 glands on each side and one at the apex; heads solitary at the 
ends of the branches or in clusters of 2 or 3; peduncles 3-10 cm. long; involucre campanulate, 
nearly 1 cm. high; bracts 5, linear-oblong, round-keeled on the back, gibbous at the base, 
purple, or purple with green backs, with 2 rows of glands; corollas about 5 mm. long; tube 
yellowish, longer than the funnelform purple throat; lobes lanceolate; achenes 6 mm. long, 
somewhat tapering at each end, dark-brown, hispidulous; pappus straw-colored, tinged with 
purple, 5 mm. long; bristles hispidulous. 
TYPE LocaLity: Sierra Madre [Sinaloa]. 
DISTRIBUTION: Southwestern Chihuahua to Sinaloa and Jalisco. 
27. Porophyllum guatemalense Rydberg, sp. nov. 
A slender shrub; branches purplish-brown, terete, striate; leaves opposite, short-petioled; 
blades thick, narrowly oblanceolate, 1-3 cm. long, with 1 or 2 large oblong glands on each 
margin and one at the apex; heads many-flowered, cymose; peduncles 1—4 cm. long; involucre 
campanulate, about 1 cm. high, purple; bracts 5, oblong, acute, round-keeled and somewhat 
gibbous below; glands linear, in two rows; corollas purplish, 7-8 mm. long; tube much longer 
than the funnelform throat; lobes lanceolate; achenes dark, 6-7 mm. long, hispidulous; pappus 
7 mm. long, tinged with purple. 
Type collected near Newton, Guatemala, 1895, E. W. Nelson 3523 (U.S. Nat. Herb.). 
28. Porophyllum simplex M. E. Jones, Contr. West. Bot. 12: 46. 
1908. 
An annual, or more probably a perennial; stems branched, striate, glaucous, 5 dm. high or 
more; leaves alternate, linear or narrowly oblanceolate, 1-5 cm. long, acute, with a few mar- 
ginal glands or glandless; heads at the ends of the branches; peduncles 3-8 cm. long; involucre 
oblong-campanulate, 9-10 mm. high; bracts 5 or 6, linear, acuminate,'strongly purple-dotted, 
round-keeled on the back, gibbous at the base; corollas purple, 6-7 mm. long; tube much longer 
than the funnelform throat; lobes lanceolate; achenes 5 mm. long, almost black, hispidulous, 
tapering above; pappus tawny, tinged with purple, 5 mm. long; bristles hispidulous. 
TYPE LOCALITY: Guayanopa Cafion, Sierra Madre Mountains, Chihuahua. 
DistripuTion: Chihuahua. 
29. Porophyllum filiforme Rydberg. 
Poropholiim filifolium A. Gray (; S. Wats. Proc. Am. Acad. 18: 107, hyponym. 1882), Proc. Am. 
ead. 19:35. 1883. Not P. filifolium DC. 1836. 
A perennial herb, with a slender woody caudex; stems rigid, branched above; leaves 
alternate, filiform, 1-5 cm. long; heads solitary at the ends of the branches; peduncles 2-5 
cm. long; involucre campanulate, about 8 mm. high; bracts 5-8, obovate, rounded or truncate 
at the apex, dark-purple, with 2 rows of linear glands, round-keeled and gibbous at the base; 
corollas purple, 5 mm. long; tube shorter than the elongate-funnelform throat; lobes lanceo- 
late; achenes 5 mm. long, hispidulous; pappus ochroleucous, purple-tinged, 3-4 mm. long; 
bristles hispidulous. 
TYPE Locality: Sierra Madre, south of Saltillo, Coahuila. 
DISTRIBUTION: Coahuila. 
