294 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
The following material has been examined: 
Durango: Papasquaro, E. W. Nelson, August 7, 1808 (no. 4671, type); not far 
from Durango City, Dr. FE. Palmer, 1896 (no. 270), 
Chihuahua: High plain between Cusihuisiachic and Guerrero, C. Ci. Pringle, 
September 5, 1887 (no. 1244). 
Type U.S. National Herbarium no. 332725. 
Lavauxia palustris Rose, sp. nov. 
Acaulescent, perennial; basal leaves erect, narrowly lanceolate, sometimes 10 em. 
long, acute, nearly entire above, more or less lacerate below, shortly petioled, puber- 
ulent; calyx tube slender; tips of calyx lobes linear and free in bud; fruit sessile, 
winged, 14 mm. long. 
Collected by Dr. C. G. Pringle in damp hollows just south of Buena Vista Station, 
Hidalgo, August 10, 1904 (no, 8929). 
Type U. 8. National Herbarium no. 462042, 
This species is somewhat similar to £. friloba, but has differently cut leaves. 
THE SUBFAMILY LOPEZIEAE. 
Dr. Rudolf Raimann, in Engler & Prantl’s Pflanzenfamilien, has very 
properly proposed the name Lopezieae for the irregular-flowered divi- 
sion of the Oenotheraceae. He includes four generain this group. Of 
these four genera three are monotypic, and hence practically all the 
species of the group belong to one venus, viz, Lopezia. In the genus 
Lopezia 33 species have been named or described and a considerable 
number of new ones have recently been collected, of which 9 are to be 
found in this paper. 
A careful review of the material which has been accumulating in the 
National Herbarium leads me to the conclusion that there are three 
genera to be taken out of Lopezia, each of which contains two species. 
Of the other genera, Semeiandra and Diplandra, a representation 
has recently been added to the National Herbarium, but Reisenbachia 
is only known to me from Presl’s plate. 
The following key to seven genera should be helpful: 
KEY TO GENERA, 
Petals none; stamen one.......2......0.2.-.022.---2------------ REISENBACHIA. 
Petals 4; stamens two. | 
Stamens alike and perfect.........-...-..-.--.---2---.------- DIPLANDRA, 
Stamens dissimilar, only one perfect. 
Sepals more or less united into a tube. 
Calyx tube long and slender; stamens long-exserted.. SEMELANDKA. 
Calyx tube short; stamens shorte ethan the calyx.... PELoztra. 
Sepals distinct or nearly sO. 
Petals sessile; style and stamens long-exserted. 2.2... PSEUDOLOPEZLA. 
Petals more or less stalked. 
Flowers large (20 mm. or more long); shrubs 15 to 
PO mm. long.......2.......---..--........---- JEHLIA, 
Flowers small (7 mim. or less long), annuals... 2. _LOPEZIA, 
