Sidalcea hickmanii subsp. pillsburiensis

S. R. Hill

J. Bot. Res. Inst. Texas 2: 786, figs. 2 – 4. 2008.

Common names: Lake Pillsbury checkerbloom
Conservation concernEndemic
Treatment appears in FNA Volume 6. Treatment on page 337. Mentioned on page 335, 338.
Revision as of 23:42, 27 May 2020 by imported>Volume Importer

Plants greenish, 0.1–0.4 m, with small, erect, branched caudex and taproot. Stems erect, green, stellate-hairy, hairs appressed, moderately dense, uniform, 0.2–0.5 mm. Leaves: stipules wide-lanceolate, 3 × 1.3 mm; petioles of midstem leaves 0.6–2 cm, 1/2 times to as long as or longer than blade; blade broadly flabelliform, usually truncate, sometimes wide-cuneate, unlobed, 0.6–1.5 × 0.7–2.2 cm, margins coarsely crenate, surfaces tufted-stellate-hairy. Inflorescences open, not spiciform, unbranched, to 10 cm, to 10-flowered, proximal flowers solitary, axillary; bracts 2 in proximal flowers, 1 in distal flowers, distinct, oblong, narrow, cupped, 3 × 1.2 mm, narrowest at base, longer than pedicels, much shorter than calyx. Pedicels 2 mm, usually not obscured by bracts; involucellar bractlets 3, oblong, 3 mm, 1/2 as long as calyx. Flowers bisexual; calyx 4–5 mm, to 5.5 mm in fruit, densely stellate-puberulent, hairs 0.1–0.6 mm diam.; petals pale pink, slightly pale-veined, 8–10 mm; staminal column 5 mm, minutely puberulent; anthers white; stigmas (4–)6 or 7. Schizocarps 4–5 mm diam.; mericarps usually (4–)6 or 7, 1.5–2 mm, side walls smooth, back and margins with 2–5 corrugations. Seeds 1–1.5 mm.


Phenology: Flowering (Jun–)Jul–Aug.
Habitat: Chaparral, ephemeral drainages
Elevation: 700–800 m

Discussion

Subspecies pillsburiensis is known from a single population near Lake Pillsbury, North Coast Ranges, Lake County. It appears to be a dwarf most closely related to subsp. viridis and differing in its lower stature, undivided (non-two-fid) bracts, fewer flowers, and less conspicuous, appressed indument.

Of conservation concern.

Selected References

None.

Lower Taxa

None.