STUDIES IN THE COMPOSITA. 59 
parently really perennial, though never with that proliferous 
or stoloniferous underground spreading and propagation 
which characterizes Solidago and true Aster. 
* MACHJERANTHERA proper. Root annual; stem diffusely 
branched; leaves 1—3-pinnately cleft; achenes terete, strongly 
striate. 
1. M. TANACcETIFOLIA, Nees, Ast. 224 (1832). Aster tana- 
cetifolius, HBK. Nov. Gen. & Sp. iv. 95 (1820).—For other 
synonymy of this southerly species, see Gray, Syn. Fl. 206. 
2. M. PARVIFLORA, Gray, Pl. Wright. i. 90 (1852). Aster 
parviflorus, Gray, Bot. Calif. i. 322. —Of southern Arizona 
and New Mexico. 
** Subgenus DrEgTERIA. Biennials and perennials; stems 
paniculately or even virgately branched ; leaves of firm texture, 
merely toothed, sometimes entire; achenes compressed, less striate. 
3. M. canescens, Gray, Pl. Wright. i. 89 (1852), excl. var. 
: Aster canescens, Pursh, Fl. ii. 547 (1814). Dieteria canescens, 
Nutt., Trans. Am. Phil. Soe. vii. 300 (1840). Biennial, erect, 
seldom a foot high, fastigiately of hore corymbosely branch- 
ing,the herbage t: early cauline leaves 
(fallen before the flowering) spatulate, commonly with a few 
serrate teeth ; those of the branches linear, or at least nar- 
rowly Baa entire: bracts of the involucre in about 
3 series, their lanceolate green tips ascending or slightly 
spreading: rays rather deep blue than purple. 
Exciusively a northern plant, of Dakota and northward 
and westward along the British boundary. It is the plant 
. of Pursh beyond all doubt, and of very marked habit. Mr. 
_ Canby long ago distributed representative specimens from 
. several localities in Dakota, and Mr. Macoun as recently as 
.. 1895 obtained a fine series in Assiniboa; his n. 10230 show- 
— ing the plant well in flower, with adum and early cauline 
