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

Holodiscus discolor is usually top-killed by fire. Once the fire has passed over sprouting occurs in the root crown. This sprouting allows it to survive large severe wildfires. Holodiscus discolor also grows from seeds either from birds or the seed bank that is already established. It takes 5 to 10 years to recover from a fire and is often important for early shrubfields after a fire.

Reproduction

Seeds: Seeds from Holodiscus discolor are dispersed by wind and animals. The seeds are also come in a seed bank. Viable seed are more common in undisturbed soils compared to clearcut and early seral succession. 

 Germination: Fresh seeds are dormant in fields and requires overwintering to germinate. Temperatures need to be at around 41OF for 15 to 18 weeks to break the dormancy in a laboratory. Holodiscus discolor have a low viability and only 7% of given seeds may be sound. 

 Growth: Seedlings grow slowly in the first 2 years of development. If overstory is removed or sparse in the area then the growing can increase rapidly.

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.