348 PROCEEDINGS OF THE AMERICAN ACADEMY. 
Geraea in the section Euencelia, and Barrattia in Simsia. Since Dr. 
Gray’s treatment nothing has been done in the way of a revision of 
the group as a whole, nor has any new species been described under 
any of the genera Pallasia, Armania, Geraea, Barrattia, or Simsia 
since 1859. 
In 1871 D. C. Eaton !8 described as Tithonia argophylla a remarkable 
new species from Utah, with large solitary heads, squamellaceous 
corona between the awns of the achene, and densely silvery-pubescent 
basal leaves, which two years later was referred to Encelia by Dr. 
Gray,!® who at the same time added a very similar new species (E. 
nudicaulis). Ten years after Gray 7° transferred them to Helianthella, 
instituting for their reception the new section Enceliopsis. In 1909 
Aven Nelson ?! elevated the group to generic rank, mainly on the basis 
of habit, enumerating five species, one of them new, which I have not 
been able to separate from FE. nudicaulis. 
Hemsley 7? in 1881 listed 17 species of Encelia from Mexico, de- 
scribing one new species and making many new combinations of names 
which had been first published under Simsia. 
In recent years the boundaries of the genus Encelia have been 
stretched to include a number of shrubby Mexican species, usually 
described from material without ripe fruit, which in the light of all 
their characters require transferral to other genera (Viguiera, Flouren- 
sia, Verbesina) if generic distinctions in this group are to be preserved. 
Six species (E. hypargyrea, maculata, montana, Pringlei, rhombifolia, 
squarrosa), with achenes plumpish when mature, so far as known, and 
a persistent pappus of two aristate or paleaceous awns and several 
short truncate squamellae, exactly agree with Viguicra in essential 
characters and are further on transferred to that genus. Another 
fascicle of six species (E. collodes, glutinosa, microphylla, oblonga, 
resinosa, suffrutescens) is not so easily placed owing to lack of ripe 
fruit in nearly every species, but all differ in more or less essential 
characters from the true genus Encelia, and may by a slight extension 
of character be included in Flourensia DC.23 This genus, wrongly 
referred by Bentham 74 to Helianthus, was based on four species, two 
radiate Chilean Plants and two discoid Mexican species, the latter 
taken by mince as nile of the genus. One of the Chilean species, 
18 In Wats. Bot. ines Res, v. 423 3 (1871 i 
1 c. Am. Acad. viii. 657 Bogle 23 Prod. v. 592 (1836). 
20 Sen Am. Acad. xix. 9 (1883). 24 Gen. PI z "as (1873). 
21 Bot. Gaz. xlvii. 432 (1909). 25 Proc. Am. Acad. xix. 7 ie 
22 Biol. Centr.-Am. Bot. ii. 183-5 (1881). 
