146 BOTANY. 



pubescence; stems many, branching, 3-6' long; leaves linear-spatulate, 9-15" 

 long; beads sbowy, very many, sometimes leafy-bracted, but mostly on 

 naked peduncles 1' long ; involucre hemispberical, 5-6" wide, the scales in 

 about 3 series, the broad white scarious margins deeply fringed ; rays pink ; 

 pappus of the ray composed of minute lacerate scales 4" long, that of the 

 disk of stout bristles 14" long, with a few shorter ones intermixed; achenia 

 minutely pubescent.— Wyoming to Arizona and New Mexico, Shore of 

 Stansbury Island, Great Salt Lake, 4,250 feet elevation ; June. (520.) 



Mach^rantheea^ canescens, Gray. PI Wright., 1. 89. Commonly 

 canescent with a minute soft pubescence ; stems several from a usually 

 biemiial root, 6-18' high, much branched ; leaves spatulate or somewhat 

 lanceolate, all but the lowest sessile, usually pinnately dentate with sharp 

 recurved teeth, varying to entire, obtuse or acute, often mucronulate ; heads 

 many, panicled or somewhat corymbose ; involucres 4-5" wide, the scales 

 ovate, oblong or even hnear, with rather acute, herbaceous, puberulent or 

 viscidly glandular tips, the outer ones shorter and squarrose or recurved ; 

 achenia pubescent. — Oregon to Arizona and Texas, Wyoming and Colorado. 

 A most variable plant, several forms occurring in this collection. 



1. Glabrous, much branched ; leaves spatulate, more or less toothed ; 

 involucral scales lanceolate, minutely resinous, the tips green, squarrose. — 

 Valleys of Central Nevada; 6,000 feet elevation; July, August. (521.) • 



2. Minutely pubescent, many stemmed ; leaves spatulate, entire or few- 

 toothed at the apex ; scales ovate-oblong, the tips green, squarrose. — Bear 

 River Canon, Uintas ; 8,000 feet elevation; August. (522.) 



3. Minutely canescent, mostly branched ; leaves oblanceolate or spatulate, 

 often broadly so, more or less spinulose-toothed ; involucre of lanceolate 

 appressed scales, the tips slightly spreading.— The commonest form and near 

 to var. latifolia, but the involucral scales are not subulate. Mountains and 

 foot-hills, from Western Nevada to the Wahsatch ; June-September. (523.) 



1 MACHiERANTHEEA, Nees. Heads many-flowered ; the rays conspicuous, pistillate, fertile, in 

 one species neutral ; disk-flowers perfect, the coroUa tubular, 5-toothed. Involucre ovoid-liemisplierica], 

 tlie scales imbricated in several series, oblong or linear, with spreadiug or recurved herbaceous points. 

 Receptacle flat, honeycombed, the cells with toothed edges. Appendages of the style narrowly lanceo- 

 late, minutely hirsute. Anthers said to have " cultriform appendages." Pappus of numerous very 

 unequal scabrous and rather rigid bristles, that of the ray-iiowers somewhat shorter. Achenia obovate- 

 fusiform, slightly compressed, indistinctly striate, pubescent or silky. — Herbs, annual, biennial or peren- 

 nial, with branching stems and pinnatifid, toothed or oven entire leaves. Genus very near to Aster, but 

 may be easiest distinguished from it by the unequal pappus of disk and ray. Consists of four species, 

 iound in the region extending from Oregon to Colorado and southward to Mexico. 



