Lycopodium arbuscula Kaulf.; L. menziesii Hook. & Am.; L. pennigerum Gaudich.; Selaginella arbuscula var. menziesii (Hook. & Grev.) Skottsb.; S. arbuscula f. parvula (Hillebr.) 0. Deg. & I. Deg.; S. flabellata sensu Underw., non Spring; S. menziesii (Hook. & Am.) Spring; S. parvula Hillebr.; S. springii Gaudich.

Common names: lepelepe a moa (comb like that of a chicken).

Endemic

Latin arbuscula, a diminutive tree, alluding to the resemblance of this plant to a small tree or bush.

Plants medium-sized, terrestrial. Stems erect from decumbent bases, unbranched in lower 1-2 and pinnately branching abundantly above (occasionally branching near bases), usually flattened in one plane, 6-60 cm long, without swollen joints, bladelike portion ranging from much-branched, ovate, or obovate to fan-shaped, or seldom branched and lanceolate, dark green to light green; rhizophores restricted to bases of stems (rarely, along lower 1/4), often inconspicuous, filiform, less than 3 cm long, about 0.2 mm in diam.; sterile leaves on main stem of 2 kinds in 4 rows, slightly separated at bases, becoming more imbricate in upper stems and branches; lateral leaves flat to firm, convex to ovate-oblong, 2-6 x 1-3.5 mm, membranous, tips acute, apiculate to long-acuminate; median leaves ovate, ovate-lanceolate, to narrowly triangular, 1-3 x 0.5-1.5 mm, tips acute; fertile leaves ovate to ovate-lanceolate, keeled, long-acuminate, tips acute. Strobili at tips of branches, narrower than stems, 3-50 mm long, square.

Common on shaded soil, rocks, and cliffs in mesic to wet areas, 100-1,200 m, all major islands. Also reported from the Marquesas Islands. If truly there, it is not endemic to Hawai'i.

Selaginella arbuscula is extremely variable in size, branching patterns, leaf color and tex-ture, leaf margin characters, and length of the strobili. On Kaua'i and O'ahu, small, delicate plants only 2-15 cm long form appressed mats on vertical cliffs and are prostrate on rocks in wet areas, often near waterfalls. This species needs careful study, because more than one species may be present in this variable taxon.

Selaginella arbuscula may be distinguished from other selaginellas in Hawai'i by its often inconspicuous rhizophores that are less than 3 em long and found only at the very base of the decumbent part of the stem.