Genus 82. THISTLE FAMILY. 509 
2. Tetraneuris stenophylla Rydb. Narrow- 
leaved Tetraneuris. Fig. 4538. 
Herranesiris stenophylla Rydb. Bull. Torr. Club 33: 155. 
1906, 
Perennial with a branched caudex, the branches 
often 34’ long, the upper portion covered with the 
scarious bases of old leaves. Bases of the leaves 
dilated, sparingly silky-villous; blades narrowly lin- 
ear, 1’-1}' long, about 1” wide, glabrous, conspicu- 
ously punctate; scape 2’-4’ high, minutely strigose; 
involucre 5-7” wide; bracts oval or oblong-acutish; 
rays about 5” long and 2” wide. 
In dry soil, Kansas to Colorado and Mexico. Formerly 
confused with T. scaposa (DC.) Greene. 
Tetraneuris fastigiata Greene, of Kansas, differs by 
the leaf-bases and involucre being more densely pubes- 
cent; it is known only from imperfect specimens, and 
may not be distinct from T. stenophylla, over which it 
has priority of publication. 
O 
3. Tetraneuris acatlis (Pursh) Greene. 
Stemless Tetraneuris. Fig. 4539. 
Gaillardia acaulis Pursh, Fl. Am. Sept. 743. 1814. 
T. acaulis Greene, Pittonia 3: 265. 1808. 
Actinella acaulis Nutt. Gen. 2: 173. 1818. 
Picradenia acaulis Britton, Mem. Torr. Club 5: 339. 
1594. 
T. simplex A, Nelson, Bot. Gaz. 28: 127. 1899. 
Perennial with thick roots and a stout branched 
caudex; scapes tufted, rather stout, or slender, 
densely silky or tomentose, 2’-8’ high. Leaves all 
borne on the ends of the branches of the caudex, 
linear-spatulate, entire, obtuse or obtusish, 1’-3’ 
long, 12’-3” wide, densely silky or villous; heads 
9”’-18” broad; involucre hemispheric, its bracts 
densely villous, acutish; rays 10-15; pappus of 5 
or 6, ovate or oblong, awned scales. 
In dry or rocky soil, North Dakota to Assiniboia, 
Montana, Nebraska and New Mexico. May—Aug. 
Tetraneuris scapdsa (DC.) Greene, admitted into 
our first edition as from Nebraska, is not definitely 
known north of Texas. 
4. Tetraneuris herbacea Greene. Eastern Tetra- Y 
neuris. Fig. 4540. 7 
T. herbacea Greene, Pittonia 3: 268. 1898. 
Actinia herbacea Robinson, Rhodora 10: 68. 1908. 
Perennial by-a stout thick caudex; scape stout, villous- 
pubescent, especially above, 6-8 high. Leaves linear- 
spatulate, slightly fleshy, bluntish, strongly punctate, spar- 
ingly loosely long-hairy, at least toward the base, 2’-3’ long, 
about 3” wide; heads nearly 2’ broad; involucral bracts 
oblong, obtuse and rounded at the apex, densely villous; 
rays about 15; pappus scales ovate-oblong, obtuse, acute or 
apiculate. 
Southern Ontario, Ohio and Illinois. May-June. 
83. HYMENOXYS Cass. Dict. Sci. 
Nat. 55: 278. 1828. 
[Picrapenta Hook. Fl. Bor. Am. 1: 317. 1833.] : 
Pubescent herbs with branching stems and alternate entire or dissected leaves, the blades 
or divisions narrow, usually linear or filiform, and relatively small, peduncled, radiate or 
discoid yellow heads. Involucre turbinate to campanulate, its bracts in 2 series, appressed, 
