470 CocKERELL: NorTH AMERICAN SPECIES OF HYMENOXYS 
‘ : | P. macrantha P. ligulaeflora Gm : 
P. Richardsoni Hook. | Ptah seal rig eg | £. pumila Greene 
| See eee ie ane eee 
| 
Plant abouti3cm.| Plant 13 to18cm. Plant about 13 cm. gs about 6 cm, 
i igh. high. 
Heads large, rays tee large, rays) Heads medium- about as in 
shorter than in ?. up 15 mm. long, akg ad not so. aires, 
macrantha | very “bright yellow. Ae 
veloped a 
P. Richardion, pal 
eduncles evi-| Peduncles evi- geen hardly | Peduncles _ hardly 
rem extended be- | a ep antl be- extended beyond the | olin beyond the 
ond the leaves. the lea es. 
Petes beacts joined | Gale heaniiig vari- | Outer bracts vari- yitens bracts Jones 
nearly to middle but | i Epo rather ie joined to mid- | to middle or Fess 
les éor 2 mee we rd. 
Inner bracts lan my tea erractsbroady, ton r bra sin| Inner bracts prac- 
olate, not fectoptane! strongly e fim- | ?. macrantha but the tically as P. ligudae- 
gradually _narr owed | briai pie sted nar- | apical = shorter, flora. 
totip. (Thus much xt to a green/and pale eo ellowish 
asin P. odorata/)* acuminate apex. li nie the rest of the 
| bract. 
chenes of disc- | ae wf disc- | porte oi disc-| Ach of disc- 
florets about half. flore ey a | florets narrower in| duces: peace as 
length of their co- hardly alf | ‘aaa a. their in P. ligulaeflora, not 
rollas, ngth of thelr Poach length, much more greatly shorter than 
as. ‘than batt Tength of their corollas. 
pocorn | Receptacle 
rounded Moucga 
an e low, | Receptacle ore 
title or eabefili- 
"| dric ca 
ie 
| . 
? Hai achenes| Hai achenes| Achenes reddish, 
on s | 
Feed with seddiati white; pappus-scales | but their hair white, 
| pappus-scales white white, or slightly except at base ; pap- 
ish at om | reddish at base | pus-scales white. 
Pappus-scales not | Pappus-s ales. Pa us-s yetce | Pa pages 
half length of disc- bree oN length of _— three-fourths | hardly o-thirds 
corolla. * disc ength of disc-co- | engthof oh coeie 
'rolla. 
Type from Carlton | ar from Fort Type from plains | Type from Rock 
ouse, Saskatch: eele, Wyom ing, | near Laramie Peak, Creek, | Wy me 
_ British Aies| ‘oleted by A. Nel- | ee collected | —— ty E. 
ica n, June 18, 1898. by A. Nelson, Aug. Greene, July ro 
gia 1896. 
material in hand I cannot satisfactorily distinguish more than one 
species with several races. Those who disagree with this conclusion 
will not feel obliged to follow the nomenclatural changes involved. 
It would be possible to go to an opposite extreme, and found 
a large number of specific names on the various combinations of 
slight characters of the bracts, pappus, achenes, etc., presented by 
the different specimens. I should not object at all to naming races 
on slight characters or combinations of characters, if it were possi- 
ble to prove that they possessed local constancy ; but obviously, 
* But see first footnote on page 472. 
