Ribes cereum

Wax currant

Grossulariaceae

The Basics

Taxonomy: Kingdom - Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (flowering plants). Class - Magnoliopsida (dicotyledons). Subclass - Rosidae. Order - Rosales. Family - Grossulariaceae (currant). Genus - Ribes L. Species - Ribes cereum Douglas

Ecology: Wax currant is shade intolerant. Although it sometimes grows in open coniferous forests, it occurs most often and grows most vigorously on sites without forest canopy. In central Idaho, wax currant is considered an early seral species within Douglas-fir (Pseudotsuga menziesii) habitat types. It is one of the first shrubs to dominate well-scarified sites but declines when a canopy taller than its own develops. A few wax currant may remain present to the midseral stage. Wax currant shrubs having relatively dense canopies provide favorable microsites for Douglas-fir seedlings. In the Bitterroot Mountains of Idaho, Ribes spp. play an important role in secondary succession. Their roots stabilize the soil, and their foliage may shelter fir (Abies spp.), spruce (Picea spp.), and western white pine (Pinus monticola) seedlings.

Identification

Plants 0.2-2 m. Stems spreading or arching to erect, puberulent, sparsely to copiously stipitate-glandular; spines at nodes absent; prickles on internodes absent. Leaves: petiole (0.3-) 0.6-1.2(-2.8) cm, glabrous or finely to copiously pubescent; blade almost reniform to broadly cuneate-flabellate, 3-5(-7)-lobed, shallowly cleft, (0.5-) 1-2(-4) cm, base cordate to truncate, surfaces glabrous or copiously pubescent, sparsely stipitate-glandular to downy to conspicuously stipitate-glandular and sessile-glandular, particularly noticeable on margins, lobes rounded, margins coarsely crenate-dentate, apex obtuse. Inflorescences pendent, solitary flowers or 2-8(-9)-flowered racemes, 1-3 cm, axis finely pubescent, sticky with short-stalked to subsessile glands, flowers tightly clustered at end of peduncle. Pedicels jointed, (0.4-) 1-2.2(-3.4) mm, puberulent; bracts flabellate or ovate to obovate, 3-7(-8.8) mm, pubescent, stipitate-glandular. Flowers: hypanthium white to greenish white with pink tinge, or pinkish white, narrowly tubular, tube widest at base and near throat, 5-9(-9.4) mm, densely hairy and scattered stipitate-glandular abaxially, glabrous adaxially; sepals not overlapping, spreading-recurved, greenish white to white or faintly to strongly pinkish tinged, deltate-ovate, 1-3.2 mm; petals connivent, erect, white to pink, orbiculate or flabellate, not conspicuously revolute or inrolled, 1-2.1 mm; nectary disc not prominent; stamens shorter than petals, (inserted below petals and completely included in hypanthium tube); filaments linear, 0.5-1.6 mm, glabrous; anthers pale cream-yellow to yellow, oval, 0.6-1.2 mm, apex with small, cup-shaped gland; ovary glabrous or hairy or sparsely to densely pubescent; styles connate nearly to stigmas, 7.5-11.5 mm, proximally hairy or glabrous. Berries tasteless, dull to bright red or orange-red, ovoid, 5-12 mm, sparsely glandular to glandular.

Threats

Fire effects: Wax currant regeneration is favored by short-duration, low-severity fire because soil-stored seed requires scarification to germinate. Most wax currant plants are severely damaged or killed by fire. The ability of wax currant to sprout after fire is weak. Low-severity fire may promote germination of soil-stored seed.

Pests and pathogens: White pine blister rust (Cronartium ribicola) is a fungus that attacks both wild and cultivated species of gooseberry and currant. The wild species stink currant (R. bracteosum), flowering currant (R. sanguineum), Sierra gooseberry (R. roezlii), and Sierra currant (R. nevadense) are very susceptible. The white or five-needled pine is an alternate host for the fungus. Rust of white pine has caused severe losses. Susceptible currants and gooseberries cannot be planted safely nearer than 1000 ft and preferably 0.5 mile from white pine. Ribes and white pines are adapted to disturbance and frequently co-occur in fo rest and woodland ecosystems.

Reproduction

Seed production: Wax currant reproduces mainly by seed. Shrubs of Ribes spp. begin fruiting after 3 years. Seeds require scarification to germinate. Many seeds fall beneath the parent plant; they are also dispersed by birds and mammals. Fallen seeds remain viable in the soil and duff for many years.

Vegetative regeneration: Wax currant is able to sprout from the root crown, but only weakly.

Species Distribution

Citation

USDA Plants Database
USDA, NRCS. 2016. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.

USFS Plant Database
Habeck, R. J. 1992. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.

Flora of North America
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 19+ vols. New York and Oxford.

The Jepson Herbarium
The Jepson Manual: Vascular Plants of California. B.G. Baldwin, D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken [editors]. 2012. 2nd edition, thoroughly revised and expanded. University of California Press, Berkeley, CA.

USGS Plant Species Range Maps
Critchfield, W.B., and Little, E.L., Jr., 1966, Geographic distribution of the pines of the world: U.S. Department of Agriculture Miscellaneous Publication 991, p. 1-97. Little, E.L., Jr., 1971-1978, Atlas of United States trees, volume 1,3,13,17, conifers and important hardwoods: U.S. Department of Agriculture Miscellaneous Publications.