Page authors: David Giblin, Ben Legler
Phlox diffusa
spreading phlox

Distribution: Widely distributed on both sides of the Cascades crest in Washington; British Columbia to California.

Habitat: Open, often rocky areas, mid- to high elevations in the mountains.

Flowers: May-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Butterflies, moths


Taprooted, tufted perennial, forming loose mats up to 1 dm. tall.


Leaves opposite, narrowly linear but rather soft, green and glabrous, up to 20 mm. long and 2 mm. wide.


Flowers solitary and sessile at the ends of the branches; calyx covered with loose, soft hairs, with flat, papery intervals between the herbaceous segments, the 5 lobes narrow and thickened; corolla white to light pink or blue, the tube 9-17 mm. long, nearly twice as long as the calyx, the 5 lobes 5-9 mm. long; filaments short and unequally attached in the corolla tube, style 3-parted, 5-8 mm. long; ovary superior.


Capsule 3 celled, with one seed in each cell.

Accepted Name:
Phlox diffusa Benth.
Publication: Pl. Hartw. [Bentham] 325 (-326) 1849.

Synonyms & Misapplications:
Phlox cyanea Eastw.
Phlox diffusa Benth. ssp. longistylis Wherry [KZ99]
Phlox diffusa Benth. ssp. subcarinata Wherry [JPM]
Phlox diffusa Benth. var. longistylis (Wherry) M. Peck [HC]
Additional Resources:

PNW Herbaria: Specimen records of Phlox diffusa in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Phlox diffusa checklist entry.

OregonFlora: Phlox diffusa information.

E-Flora BC: Phlox diffusa atlas page.

CalPhotos: Phlox diffusa photos.

USDA Plants: Phlox diffusa information.

94 photographs:
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