Noccaea fendleri subsp. californica

(S. Watson) Al-Shehbaz & M. Koch

Syst. Bot. 29: 382. 2004.

Basionym: Thlaspi californicum S. Watson Proc. Amer. Acad. Arts 17: 365. 1882
Synonyms: Thlaspi alpestre var. californicum (S. Watson) Jepson Thlaspi glaucum subsp. californicum (S. Watson) Munz Thlaspi montanum var. californicum (S. Watson) P. K. Holmgren
Treatment appears in FNA Volume 7. Treatment on page 602. Mentioned on page 601.

Stems (0.5–)1–1.2(–0.2) dm. Basal leaves: petiole differentiated from blade, 0.8–1.8 times longer than blade; blade spatulate to obovate, 5–7(–8) mm wide, base cuneate. Cauline leaves 2–5. Racemes lax. Fruiting pedicels strongly ascending to divaricate-ascending, forming an angle 15–70º with rachis. Flowers: petals white, 6–8 × 1.6–2.5 mm. Fruits not winged, elliptic, 0.7–10.5 × 2.7–4 mm, 2.2–3.2 times as long as wide, apex acute; style (1.3–)1.5–2(2.4–) mm. Seeds 2–6 per fruit.

Phenology: Flowering May–Jun.
Habitat: Serpentine rock outcrops
Elevation: ca. 800 m


Of conservation concern.

Subspecies californica is known from one population at Kneeland Prairie in Humboldt County. It was recognized by Holmgren as a variety of Thlaspi montanum, whereas R. C. Rollins (1993) treated it as T. californicum. In my opinion, the differences in fruit apex and size between this taxon and Noccaea fendleri are rather small and do not seem to justify its recognition as an independent species.

Selected References


Lower Taxa

Ihsan A. Al-Shehbaz +
(S. Watson) Al-Shehbaz & M. Koch +
Thlaspi californicum +
ca. 800 m +
Serpentine rock outcrops +
Flowering May–Jun. +
Thlaspi alpestre var. californicum +, Thlaspi glaucum subsp. californicum +  and Thlaspi montanum var. californicum +
Noccaea fendleri subsp. californica +
Noccaea fendleri +
subspecies +