Castilleja ambigua var. humboldtiensis

(D. D. Keck) J. M. Egger

Phytologia 90: 67. 2008.

Common names: Humboldt Bay owl’s-clover
EndemicConservation concern
Basionym: Orthocarpus castillejoides var. humboldtiensis D. D. Keck Proc. Calif. Acad. Sci., ser. 4, 16: 536. 1927
Synonyms: Castilleja ambigua subsp. humboldtiensis (D. D. Keck) T. I. Chuang & Heckard
Treatment appears in FNA Volume 17. Treatment on page 585. Mentioned on page 584.

Stems ± short-decumbent proximally, becoming erect to ascending, unbranched or few-branched from mid stem. Leaves narrowly oblong to linear, oblong, or lanceolate, cup-shaped, ± fleshy, apex rounded. Bracts proximally green or brownish purple, distally pink to purple on lobe apices; lobes ascending, oblong, 20–23 mm, usually arising above mid length. Calyces with all 4 clefts subequal; lateral clefts 3 mm, ca. 15% of calyx length. Corollas 21–24 mm; beak pink or purplish, 5–7 mm; abaxial lip yellow, becoming orange or red-purple after anthesis; teeth deep pinkish purple, often with whitish bases.

Phenology: Flowering Apr–Jul(–Aug).
Habitat: Upper margins of Salicornia salt marshes, saline flats.
Elevation: 0–10 m.


Variety humboldtiensis has purplish flowers and bract apices and is limited to the upper edge of Salicornia-dominated salt marshes in Humboldt and Mendocino counties, where it replaces var. ambigua. Most populations are around Humboldt Bay. Reports of var. humboldtiensis from Tomales Bay in Marin County are based on plants of the salt marsh form of var. ambigua and have yellowish flowers. Variety humboldtiensis is threatened by coastal development.

Selected References


Lower Taxa

J. Mark Egger +, Peter F. Zika +, Barbara L. Wilson +, Richard E. Brainerd +  and Nick Otting +
(D. D. Keck) J. M. Egger +
Orthocarpus castillejoides var. humboldtiensis +
Humboldt Bay owl’s-clover +
0–10 m. +
Upper margins of Salicornia salt marshes, saline flats. +
Flowering Apr–Jul(–Aug). +
Endemic +  and Conservation concern +
Castilleja ambigua subsp. humboldtiensis +
Castilleja ambigua var. humboldtiensis +
Castilleja ambigua +
variety +