Pseudoleskeella serpentinensis

   MEDIAN LAMINAL CELL MEASUREMENTS. -- Plants in rather glossy reddish- to brownish-green mats, strongly to not at all julaceous. Median laminal cells rhomboidal, about 2: 1 (longer on stolon leaves), with clearly pitted, rather thick walls (lumen: wall ratio about 2: 1 in older leaves and even thicker on stolon leaves). Costa fairly wide and thick, flared and often forked apically, ending at about mid-leaf but much shorter and often inconspicuous on stolon leaves, flared and often forked apically. Margin plane, not decurrent, serrulate in distal 1/2, occasionally entire on stolon leaves but often serrate in younger stem leaves. Acumen, at least of the branch leaves, consistently homomallous causing the tips of the branches to be hamate. Leaves on well-developed stems and branches which are exposed to sunlight, ovate to sub-lanceolate, 2–3: 1. Stolon leaves on undersurface of clone hyaline, ovate to nearly orbicular when well-developed, abruptly contracted from near the base into a reflexed, sub-tubular acumen. Pseudoparaphyllia lanceolate, serrate and overarching the bud. Axillary hairs 6 cells, to 75 µm, with no basal brown cell, not offset from leaf insertion. Rhizoids red to brown, fascicled on ventral portion of stem without particular regard to position of leaf insertion.

   Presumably dioicous. Perichaetial bracts serrate, hyaline, and reflexed. Perigonia and sporophytes not seen.

   This plant is restricted to serpentine rocks primarily in the drainage of the Smith River of northwestern California. It somewhat resembles P. catenulata (Brid.) Kindb. of central Europe, and was identified to that species by Lawton (1971). Its resemblance to the latter species is the basis for the assignment of this plant to Pseudoleskeella despite its lack of sporophytes.

Vouchers: Del Norte Co.: Smith River at Highway 199, Jedediah Smith Redwoods State Park, Norris 68927 and Middle Fork Gasquet Road along trail to Stony Creek, Wilson 943 & 945 (UC) and west side Smith River about one mile west of Gasquet, Norris 70340; Humboldt Co.: junction of Red Mountain and South Red Mountain Road, Norris 56452 & 56456; Siskiyou Co.: trail from Wilderness Falls toward Doe Flat, Klamath National Forest, Norris 67821 and Doe Creek, Norris 23069; Sonoma Co.: The Cedars about 7 miles north of Cazadero, Robertson 1580 (CAS) & 1561 (UC).

Literature: Wilson and Norris 1989.

Illustration References: Malcolm et al. 2009 p. 255; Wilson and Norris 1989.

No illustrations found in database.

Elevation by latitude plot for Pseudoleskeella serpentinensis
   in California