296 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
KEY TO MEXICAN SPECIES OF RIBES., 
Leaves thick, Viburnum-like; racemes several in the axils of the leaves; calyx with 
a prominent horizontal disk ........-..-------------------- 1. RR. viburnifoliam. 
Leaves thin, of the ordinary type; racemes solitary in the axils of the leaves; calyx 
tubular; disk wanting. 
Stems more or less prickly. 
Petioles about the length of the blades, pilose; blades strongly nerved; 
Central Mexican species. ......-..----------4------ 2. Ro microphylhan, 
Petioles more or less elongated, pubescent but not pilose; blades not 
strongly nerved; United States species ranging into Lower California. .~-- 
3. A. quercetorum. 
Stems not at all prickly. 
Flowers yellow; calyx tube much elongated... 2.2222... -- 4. 2B. longiflorwn. 
Flowers generally not yellow; calyx tube much shorter than the last. 
Anthers not tipped with a depressed gland. 
Calyx elongated; leaves glandular; fruit black... .-- 5. BR. nelsoni. 
Calyx short; leaves not glandular; fruit reds. 2... - 6. I. tortuosum. 
Anthers tipped with a depressed gland, 
Ovary glandular-pubescent. 
Pedicels with scanty hairs; ovary very glandular 2.22.2... 
7. R. pringlei. 
Pedicels with dense pubescence; ovary not very ghindular. - 
8. 2. neglectum. 
Ovary glabrous. 
Calyx tube shorter than the lobes. 
Lobes of leaves acute. 
Leaves glabrous above, the margin with glandular 
hairg.......-.----------------- Sal Ro orizabae, 
Leaves pubescent above, the margin without gland- 
ular hairs. 
Bracts scattered on pedicels. 2.2 9. Re hunthii, 
Bracts at topof pedicels. 2... .. Ya. LR. affine. 
Lobes of leaves obtuse. 22... 2... ..---- 10. BR. dugesii. 
falyx tube longer than the lobes. 
Young branches often very glandular-pubescent; leaves 
with long-stalked glands. 2.2.2.2... lL. A. eiliatum, 
Young branches not glandular-pubescent; leaves 
eglandular or with a few short-stalked glands. 
Leaves glabrous above, nearly so beneath ......-- 
12. BR. eeriferwn. 
Leaves pubescent on both sides, often densely so 
beneath. 
Branches short and stout, becoming light 
brown, soon glabrate . 2... IS. AR. ragosum. 
Branches elongated, slender, becoming a dark 
5 ’ : 
purple, puberulent.......-- It. RB. grande. 
Ribes viburnifolium Ciray, Proc. Am. Acad. 17: 202. 1882. 
Ribes viburnifolium differs from Ribes proper in having several racemes ina cluster, 
in the peculiar foliage, the rotate calyx, and the well-developed horizontal disk on 
which are borne the stamens and petals. It is confined chiefly to Lower California 
and its neighboring islands, but has been reported once from Sonora. 
Ribes microphyllum I. B. Kk. Nov. Gen. & Sp. 6: 62. 1825, 
A bush, 1.5 to 3 meters high; bark of old wood nearly black, of first-year branches 
light-colored; spines stout, usually single; petioles slender, longer than the blade, 
