Blake — A Revision of the Genus Viguiera 13 
Viguiera, most of whose species have strongly paleaceous awns in 
the pappus, may be related to Helianthus, but such a connection 
is scarcely indicated by any existing species. 
Of all the problems connected with the genera here discussed, 
none is more puzzling than that presented by the genus Gymnolo- 
mia. The perplexing interrelationships shown by several of the 
species of this genus and species of Viguzera have already been 
brought to attention by Robinson and Greenman ' in their revision 
of Gymnolomia in 1899. Before discussing the relationships of the 
two groups, a note as to the nomenclature of Gymnolomia is in 
order. The true genus Gymnolomia HBK.2 (1820) was founded on 
four species of Colombia and Peru, all of which (with the possible 
exception of G. si ance in which the pappus is unknown) have a 
d achen t both ends and bearing a short 
coroniform lacerate pappus. They form, in fact,a genus very closely 
related to Aspilia and perhaps identical, but of no close affinity to 
the Viguiera group. With them are apparently congeneric G. hirsuta 
Klatt and G. Jelskit Hieron. of the same region. G. ? subfleruosa 
pops ) B. & H. has proved to be referable to Hymenostephium; 
G. cruciata Klatt is a synonym of Wulffia baccata (L. f.) Ktze.; G. 
serrata Rob. & Greenm. proves to be a Verbesina; anda cherbon 
of type specimens has shown that G. decumbens Robinson is a 
synonym of G. flava Hemsl., while the collection (Ghiesbreght 383) 
which was treated by Robinson and Greenman, following Gray, as 
G. flava, represents an allied but undescribed species. The remain- 
ing species of Robinson and Greenman’s revision, with the five or 
six good species since published,’ form a group ot some 36 species 
very variable in habit but all characterized by an absolute lack of 
pappus. On this basis, were it not for the evidence to be drawn 
‘from-all their other characters, they might be retained as an 
* Rob. & Greenm. Proc. Bost. Soc. Nat. Hist. xxix. 87-88, 101 (1899). 
? HBK. Nov. Gen. iv. 217 (1820). 
* The two followin shan ies, lately published vaenin Gymnolomia, are synon- 
ymous with species of other genera. — One, G. acuminata Blake in _ Proce. 
Am. Acad. xlix. 505 (A013), is identical with Bclatcnr pres Schiedeanus (DC.) 
H. var. elongatus Greenm nbn Am. Acad. xxxii. 309. (1897). The recent 
elevation of this agg tos c rank, as S. elongatus (Greenm.) Greenm. & 
hompson, Ann. Mo. Bot. Card. i. 412 (1915) is not supported by the rather 
extensive material ‘s the Gray Herbarium. It may be saben whether S. 
Schiedeanus is )B. & 

x.) EB: .— Th 
other is G. scaposa pennies: Univ. Calif. Pub. Bot. iv. 93 ani), which, as 
has been indicated by Dr. Robinson, Proc. Am. Acad. xlvii. 211 (1911), is syn- 
onymous with J ostephane trilobata Hemsl. Biol. Centr.-Am. Bot. ii. 169 (1881). 
