Desert Spikemoss

Selaginella eremophila is most closely related to the Mexican S . parishii L. Underwood and S . landii Greenman & Pfeiffer. In S . eremophila and the following two species, S . arizonica and S . peruviana , the leaves are arranged in 8 conspicuous ranks: 3 underside (2 marginal, 1 central), 2 lateral, and 3 upperside (2 marginal, 1 central).

Plants on rock or terrestrial, forming dense mats. Stems not readily fragmenting, prostrate, upperside and underside structurally different, irregularly forked; branches determinate, tips upturned. Rhizophores borne on upperside of stems, throughout stem length, 0.2 mm diam. Leaves conspicuously dimorphic, in 8 ranks, tightly appressed, ascending, green; abaxial ridges present; apex with deciduous, twisted, transparent bristle ± 0.3 mm, becoming acute to slightly mucronate in oldest branches. Underside leaves lanceolate to lanceolate-elliptic (on central ranks) or falcate (on marginal ranks), 2--2.7 X 0.5--0.7 mm; base decurrent, glabrous; margins ciliate, cilia transparent to opaque, spreading, 0.04--0.1 mm. Upperside leaves lanceolate, 1.3--1.4 X 0.3--0.4 mm; base abruptly adnate, pubescent, hairs often running along groove; margins ciliate, cilia transparent to opaque, spreading, ca. 0.1 mm. Strobili solitary, 3--8 mm; sporophylls ovate-deltate, abaxial ridges not prominent, base glabrous, margins ciliate, apex acute to mucronate.

Ariz., Calif.; Mexico in Baja California.

Rocky and sandy slopes, in open rock or crevices or in soil; 130--1000m.

Selaginella eremophila is a species of spikemoss known by the common name desert spikemoss. It is native to the deserts and adjacent mountains around the intersection of California and Arizona with Baja California. It grows in sandy and rocky habitat. This lycophyte forms dense mats of spreading stems with small, forking branches. The lance-shaped leaves are up to 3 millimeters long on the lower stem surfaces and a little shorter on the upper sides. The tiny leaves have pointed tips with soft, twisted bristles. The strobili bearing the reproductive parts are under a centimeter long.