Holodiscus discolor

Oceanspray

Rosaceae

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 - Rosaceae (rose). Genus - Holodiscus (K. Koch) Maxim. Species - Holodiscus discolor (Pursh) Maxim.

Ecology: Oceanspray is important or dominant in many plant communities of the Pacific Northwest, California, and the Northern Rocky Mountains. These communities include seral and old-growth conifer, seral and old-growth hardwood, mixed-riparian, and mixed-shrubland types. Oceanspray is most common in early succession but occurs in all stages of succession. Oceanspray prefers open sites - it is described as a light demanding, early successional species. Logging and fire promote creambush oceanspray by opening the canopy.

Identification

Habit: Plant 0.3--6 m. Stem: bark +- red, in age gray, shredding; twigs glabrous to hairy, occasionally glandular. Leaf: 0.3--8 cm, ovate to obovate, strong-veined abaxially, glabrous to hairy, occasionally glandular, teeth entire to compound; base truncate to wedge-shaped; petiole distinct or not. Inflorescence: 2--25 cm, 1.5--25 cm wide. Flower: hypanthium 3--5 mm wide; sepals 1--2 mm; petals 1.5--2 mm; style 1 mm. Fruit: achenes 1--1.5 mm, often with sessile glands. Note: Highly variable; varieties intergrade.

Threats

In the WFDP: Oceanspray is susceptible to suppression-induced mortality in this energy-limited system. The primary pathogen affecting oceanspray in the WFDP is Armillaria root rot (aka Honey fungus; Armillaria spp.).

Fire effects: Oceanspray is usually top-killed by fire, then sprouts from the root crown and establishes from seed after fire. Sprouting allows oceanspray to survive large, severe wildfires.

Reproduction

Seed dispersal and growth - Oceanspray seed is disseminated by wind and animals. Oceanspray has a soil seed bank, but seed may have low viability. Seedling establishment is uncommon and seedlings grow slowly.

Vegetative regeneration - Oceanspray sprouts from the root crown after top-kill. It may also reproduce by layering.

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. $131.95, hardcover; 1600 pages. ISBN-13: 978-0520253124.

Burke Museum of Natural History and Culture
Burke Museum. 2016 [Online]. University of Washington.