Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.
Search native plant database:
Bransford, W.D. and Dolphia
Rhododendron macrophyllum D. Don ex G. Don
Pacific rhododendron, California rhododendron, California rosebay, Red rhododendron
Synonym(s): Rhododendron californicum
USDA Symbol: rhma3
USDA Native Status: L48 (N), CAN (N)
California rhododendron is a 5-25 ft. evergreen shrub with large whorls of leathery, dark-green, oblong leaves setting off spectacular flower clusters. Individual flowers are bell-shaped and range in color from pink to deep rose-purple. When growing in woods, the plants become tree-like to 25 ft. with an attractive, leggy appearance. When open-grown the plant is shorter and more compact. Evergreen shrub with large, deep green, leathery leaves and rounded clusters of large, pink, tubular flowers.
This is the showiest flowering shrub in the forests of western North America, with flower clusters that nearly rival in size and number those of its cultivated relatives. Pacific Rhododendron is confined to drier forest environments in western Washington, where it is the state flower. These same environments, however, are among the moister ones occurring in northern California, at the southern limit of this shrub’s range. The plant is most abundant in Oregon, where mass displays provide a spectacular show in late spring and early summer.
Plant CharacteristicsDuration: Perennial Habit: Shrub Leaf:
Dark Green Flower:
Fruit: Size Class:
Bloom InformationBloom Color: Pink , Purple
Bloom Time: Apr , May , Jun , Jul
, WA Canada: BC Native Distribution:
Coastal B.C. & WA,
through the Cascades to n. CA; isolated stations on Vancouver Island Native Habitat:
Coastal, montane conifer woods
Growing ConditionsWater Use: High
Light Requirement: Part Shade , Shade
Soil Moisture: Dry , Moist
Soil pH: Acidic (pH<6.8)
CaCO3 Tolerance: None
Soil Description: Moist to drier, well-drained soil.
Conditions Comments: Not Available
BenefitWarning: Rhododendrons contain poisonous substances and should not be ingested by humans or animals. Honey made from flowers also may be toxic. POISONOUS PARTS: All parts. Highly Toxic, May be Fatal if eaten. Symptoms include salivation, watering of eyes and nose, abdominal pain, loss of energy, depression, nausea and vomiting, diarrhea, weakness, difficult breathing, progressive paralysis of arms and legs, coma. Toxic Principle: Andromedotoxin. (Poisonous Plants of N.C.)
Conspicuous Flowers: yes
PropagationDescription: Combine seeds loosely with sphagnum moss and sprinkle lightly over a 2:1 perlite/peat mixture. Optimum temperatures for germination are 45-50 degrees. Transplant seedlings to acid soil with a high content of organic matter. Propagation is also accompli
Seed Treatment: No pretreatment is necessary.
Commercially Avail: yes
National Wetland Indicator Status
|Status:|| FACU |
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1
(Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here
for map of regions.
From the National Organizations Directory
According to the species list provided by Affiliate Organizations, this plant is either on display or available from the following:
Santa Barbara Botanic Garden
- Santa Barbara, CANative Seed Network
- Corvallis, OR
Record Last Modified: 2010-12-18
Research By: TWC Staff