Orobanche valida subsp. howellii

Heckard & L. T. Collins

Madroño 29: 98, fig. 1A–E. 1982.

Common names: Howell’s broomrape
Endemic
Synonyms: Aphyllon validum subsp. howellii (Heckard & L. T. Collins) A. C. Schneider
Treatment appears in FNA Volume 17. Treatment on page 486. Mentioned on page 485.

Plants (6–)10–20 cm, base often slightly enlarged. Bracts, bracteoles, and calyces densely glandular-pilose, hairs 0.2–0.4 mm. Corollas 14–16(–18) mm; palatal folds puberulent; lips and tube densely glandular-pilose throughout, hairs 0.4–0.7 mm; filaments sparsely pilose at base, anthers pilose. 2n = 48.


Phenology: Flowering Jun–Sep.
Habitat: Rocky volcanic, serpentine slopes, open chaparral.
Elevation: 1200–1700 m.

Discussion

Subspecies howellii is restricted to Glenn, Lake, Mendocino, Napa, and Tehama counties in the northern and central Coast Ranges, geographically disjunct from subsp. valida. The confirmed hosts are species of Garrya. Reports of Eriodictyon and Quercus as hosts need confirmation. Further research on this rare subspecies is warranted to establish its range and conservation status.

Selected References

None.

Lower Taxa

None.
L. Turner Collins +, Alison E. L. Colwell +  and George Yatskievych +
Heckard & L. T. Collins +
Howell’s broomrape +
1200–1700 m. +
Rocky volcanic, serpentine slopes, open chaparral. +
Flowering Jun–Sep. +
Aphyllon validum subsp. howellii +
Orobanche valida subsp. howellii +
Orobanche valida +
subspecies +