60 PITTONIA. 
leaves wanting, as they always are in this species at that ' 
stage; his n. 10232 exhibiting an earlier stage, just begin- ^ 
ning to flower; 10234 with only one head in flower, display- | 
ing all the leaves, the radical ones being entire, the proper — 
cauline serrate-toothed, those clothing the branchlets at time 
of maturity and full flowering not yet developed. All the — 
species immediately succeeding in this enumeration are of | 
different habit, none of them like this low and corymbose, — 
nor having their flowering branches clothed with those many | 
ascending entire narrow leaves. 1 
4. M. sEssILIFLORA. Dieteriua sessiliflora, Nutt., Trans. Am. [ 
Phil. Soe. vii. 301 (1840). Biennial, stout, erect, with few 
stout ascending branches, all leafy throughout, the heads 
subsessile in the axils of the green and almost glabrous : 
leaves: turbinate heads } inch high; bracts of involucre in . 
as 5 series, mainly uncolored, rather thin, the short green 
tips squarrose: rays purplish, but pale (not “ yellow ”): pap- 4 
pus whitish, scanty and fragile or deciduous; achenes pubes- 
cent. ! 
Certainly most distinct not only from M. canescens but 
from all other species, and of an easterly habitat. The only 
good specimens seen by me are in the U. S. herbarium and | 
were collected by Mr. Rydberg in the hills of western Ne- - 
braska. Nuttall’s type, or at least a probable duplicate of 
it, is in the herbarium of the Philadelphia Academy, and, 
though small and poor—not yet in flower—is well matched 
by the excellent ones referred to. Only certain Californian 
species approach this in habit, though not in character. 
5. M. montana. Nearer to M. canescens than to the last, 
but much taller, somewhat panictlately and divaricately 
branched ; all the leaves relatively narrower, the lowest only 
oblanceolate, the rameal few, spreading rather than ascend- 
ing, lanceolate rather than oblanceolate and all saliently ser- 
rate-toothed: bracts of the involucre in 4 series, with long 
and narrow squarrose herbaceous tips. 
