564 PROCEEDINGS OF THE AMERICAN ACADEMY. 
form. Great variation and closely related species indicate a recent 
genus still in process of evolution. The line separating Orthocarpus 
from Castilleja is not definitely fixed, and the species on the border 
may suffer changes in name frequently. At present the tendency is 
to remove all these doubtful species from Orthocarpus and include 
them in Castilleja, thus leaving the former genus represented only by 
annuals. The two genera are certainly very closely related, for there is 
scarcely a character of Orthocarpus which cannot be found in some 
species of Castilleja. Indeed, it is doubtful if the differences between 
the two genera are much more pronounced than are the differences be- 
tween some of the sections of Castilleja. The last enumeration of the 
Mexican and Central-American species of Castz/leja was in 1881-1882, 
when Hemsley enumerated 26 species (Biol. Cent.-Am. Bot. ii. 459-463). 
Since then great activity has prevailed in the biological exploration of 
Mexico and Central America, and specimens of Castilleja have been 
accumulating i in all the large herbaria. The present paper is based upon 
the specimens in the Gray Herbarium and some from the herbarium of 
the U. S. National Museum. Besides the key a short diagnosis of 
each species has been added, sometimes modified from the original 
description and sometimes quoted. 
Szotro I. Epicuroma Benth. in DC. Prodr. x. 528 (1846) 
Calyx vix fissus, breviter et obtuse sinuato-lobatus. Folia pinnati- 
secta ; rhachi et laciniis filiformibus vel anguste linearibus. Folia 
pies caulinis minora et concolora. Flores laxe spicati vel racemosi. 
ua. 
Flores 2.5 em. longi. Calyx coccineus infundibuliformis. bor a vol basi oo A 
PENT ee a ew Ne 
Flores 2m. longi. Calyx flavus. Galea flava exsert C. - aur pei 
Flores 1.5 cm. longi. Calyx -viridi-purpureus. ‘Galea via be ee 
exserta a Ge gracil 
“Sea, call gt, AS SI ae eee en. SNe eee sey rt SS ile oer Relate Rakes AIM a yg Scr Ske etegaee eager 
Szorro II. _ Evcnoma (N utt.) Benth. 1. c. 529. Huchroma Nutt. 
Gen. ii. 54 (1818). 
Calyx in duas partes subaequaliter fissus, segmentis integris vel 
obtuse bilobatis vel acute bifidis, Folia floralia caulinis latiora, apice 
tata et semper colorata. Flores et bracteae in spicis 00 
demum interruptae. 
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