ROSE—MEXICAN AND CENTRAL AMERICAN PLANTS. 327 
Heterocentron occidentale Rose, sp. nov. 
A shrub 180 to 200 em. high; branches 4-angled, the younger ones reddish and 
densely appressed-pubescent; leaves lanceolate, 6 to 8 cm. long, 2.5 to 3 cm. broad, 
obtuse, cuneate, often oblique at base, tapering into a distinct petiole, very pale and 
densely appressed-pubescent on both sides, with 4 or 5 pairs of lateral veins; inflor- 
escence a few-flowered cyme; calyx tube about 6 mm. high, covered with short 
broad almost triangular hairs, in age almost tubercled; calyx lobes acuminate, 
glabrous; stamens as of the genus; ovary (in specimens examined) not setose. 
Collected by J. N. Rose in the foothills of the Sierra Madre between Pedro Paulo 
and San Blascito, Tepic, August 4, 1897 (no. 1980). 
NEW SPECIES OF TWO GENERA. 
Conostegia minutiflora Rose, sp. nov. PuaTe LXXI. 
A small shrub, 90 to 240 em. high with the young branches densely stellate; leaves 
lanceolate, narrowed at base, acuminate, 5-nerved, 7 to 12 em. long, in age glabrous 
above, densely white tomentose beneath; petiole 10 to 55 mm. long; inflorescence a 
terminal panicle; flowers sessile or nearly so; buds small, 4 mm. long, acute, densely 
stellate for the lower half, the circumscissile cap glabrous or nearly so; petals pink, 
4mm. long; style 3 mm. long. 
Collected by EK. W. Nelson about Plunia, Oaxaca, altitude 900 to 1,040 meters, 
March 17, 1895 (no. 2493a). 
This species is perhaps nearest (. lanceolata, but has different pubescence, smaller 
flowers, etc. 
EXPLANATION OF PLATE LX XI.—Fig. a, plant; b, petal; c, calyx, stamen and ovary. Fig. a, natural 
size; b and ec, enlarged. 
’ 
Monochaetum pringlei Rose, sp. nov. Puate LX XII. 
A shrub; branches glabrous somewhat setose at the nodes; leaves narrowly lance- 
olate, 2 to 4 cm. long, 3 to6 mm. broad, cuneate at base, acute, glabrous aboye, with 
a few scattered hairs beneath, a little ciliate on the margin, entire, 3-nerved; petioles 
reddish, 2 to 4 mm. long; flowers solitary, terminal; peduncle 6 to 8 mm. long, with 
scattered appressed hairs; calyx-tube urn-shaped, 6 to 8 mm. long, with scattered 
appressed (some glandular) hairs; lobes 2 mm. long, obtuse, ciliate, reddish; petals 
purplish. 
Collected by C. G. Pringle near Cuernavaca, Morelos, altitude 1,950 meters, Novem- 
ber 1, 1896 (nos. 6976, 7352); Sierra de Tepoxtlan, 1890 (no. 8359, type), and 1902 
(no. 9785). 
This species differs from all the other Mexican species in having glabrous stems, 
EXPLANATION OF PLATE LXXII.—Fig. a, plant; ), flower. Figs. a and }, natural size. 
ONAGRACEAE. 
INTRODUCTORY NOTE. 
Sometime before Professor Léveill@s monograph of Oenothera 
began to appear I took up the study of our Mexican species of that 
genus with the hope of preparing a usable key. I was greatly dis- 
appointed to find that our herbarium material was very scanty and 
that a considerable number of the species are only known by the 
original collection from which they were described. Though I have 
prepared a tentative treatment of this group there are various species 
whose status is still uncertain, and as there seems to be no pressing 
need for a revision I shall withhold most of my manuscript until much 
more material has been studied. 
