Selaginella bernoullii Hieron.

Authority

Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.

Family

Selaginellaceae

Scientific Name

Selaginella bernoullii Hieron.

Description

Species Description - Stems suberect, stramineous or greenish, 9-25 cm long, 0.3-1 mm diam., not articulate, occasionally flagelliform, stoloniferous with buds at tips, 2-3 times branched; rhizophores restricted to proximal 1/4-1/3 of stems, filiform, 0.1-0.3 mm diam.; leaves of two kinds (anisophyllous) throughout, or above proximal 1/4 of stems; lateral leaves distant, ovate to ovate-oblong, 2.4-5 x 1-2.4 mm, bases rounded to subcordate, margins hyaline, entire to sparingly denticulate, especially distally, apices acute, upper surfaces usually hispid, especially near basiscopic margins, without idioblasts, lower surfaces glabrous, usually with conspicuous idioblasts; median leaves broadly ovate-elliptic, 1.3-2.2 x 0.7-1.2 mm, bases usually with the inner bases truncate and the outer bases auriculate or oblique, margins hyaline, sparsely denticulate, apices abruptly long-aristate, aristae 1/4 - 1/2 the lamina length, 0.3-1 mm long, both surfaces glabrous, without idioblasts; axillary leaves similar to lateral leaves, bases rounded; strobili dorsiventral, lax and flattened, 2-6 mm long; sporophylls dimorphic, the dorsal ones green, spreading, the ventral ones hyaline to green-hyaline, ascending; megasporangia few, 1-3 at the base of ventral rows; microsporangia in two dorsal rows or strobili almost wholly microsporangiate; megaspores cream yellow, usually without an equatorial flange or with a slightly developed one, rugulate to rugulate-reticulate, 250-300 µm diam; microspores red-orange with capitate projections.

Discussion

Lectotype (chosen here). Guatemala. Quiche´: between Cubulco and Joyabaj, Bernoulli 1121 (B!; isolectotypes B!, K!, P! [on same sheet with Bernoulli & Cario 160]).

As pointed out by Valdespino (1995), S. bernoullii has been misunderstood and synonymized under S. porphyrospora because of its hispid upper surfaces of lateral leaves and sporophylls, abruptly aristate median leaves, and frequent tubers at the bases of upright stems. Selaginella bernoullii can be distinguished from S. porphyrospora by lack of idioblasts on the upper surface of lateral leaves (vs. usually with 2 false veins, one at each side of the midrib or at least at one side), lateral leaves usually acute (vs. acuminate), and occasional flagelliform branches ending in an illdifferentiated, elongate, and rather flattened propagule with denticulate leaves (vs. flagelliform branches frequently ending in a well differentiated, round, and globose propagule or bud with ciliate leaves in S. porphyrospora). In addition, S. bernoullii differs from S. porphyrospora by its cream (vs. orange) megaspores, with or without an ill-differentiated (vs. with a well differentiated) equatorial flange, and orange (vs. reddish) microspores. In addition to reproducing sexually, Selaginella bernoullii propagates vegetatively by sending out stolons that form a tuberlike bud at the tip. These buds are reddish (Moran 5548, NY), rather elongate, stout, and covered with hyaline, scale-like leaves.Upon germination they develop suberect, branched stems. This new plant in turn can produce new stolons, repeating the cycle. Selaginella bernoullii is also characterized by asymmetric lateral and axillary leaves. In both cases the broader side (acroscopic one in lateral leaves) is at least 1.2-1.5 times wider than the other side. Purpus 6720 (US) is S. bernoullii, whereas duplicates of the same number at BM, M, NY, and UC are S. porphyrospora. Presumably, both species were growing together and were collected as part of a single gathering.

Distribution

Terrestrial or epipetric on wet and shady slopes and road banks, stream banks, or wet mossy rocks; 1300-3000 m. Mexico; Guat, Hond, Salv.

México Mexico North America| Guatemala Central America| Honduras Central America| El Salvador Central America|