Notice: Atrium is currently undergoing maintenance. During this time, some or all images may not be displayed.

Selaginellaceae

Selaginella apoda (L.) Spring

Kingdom: Plantae Rank: Species Parent: Selaginella Status: Valid

Common Names:

  • MEADOW SPIKE-MOSS - English, United States of America
  • BASKET SELAGINELLA - English, United States of America

Morphological Description

Diagnosis: Plant prostrate-creeping or ascending annual (all other TX species are perennial), often forming mats, delicately thin-herbaceous (our only such species); leaves in 4 ranks, of 2 distinct kinds, without significant hyaline margins, the two types of leaves different in size and shape—lateral leaves ovate to ovate-elliptic, asymmetrical, ca. 1.35–2.25 mm long, 0.75–1.35 mm wide; appressed-ascending (medial) leaves lanceolate, smaller, to ca. 1.2(–1.6) mm long; strobili solitary or paired, obscurely quadrangular (= 4-sided)-flattened, 0.5–2 cm long; 2–4 mm in diam.; sporophylls apically acute to acuminate.

Other

Ecology: Moist areas, ditches, stream banks, seeps, low fields, and low woods; widespread in Pineywoods (e.g., E. Whitehouse 23088, BRIT), Post Oak Savannah, n Gulf Prairies and Marshes and disjunct to e Edwards Plateau (e.g., Burnet Co., Correll & Correll 12746, BRIT, TEX-LL); e U.S. from ME s to FL w to IL, OK, and TX; also disjunct to the mts. of s Mexico and Guatemala. Sporulating May–Dec.

Notes: In flood-prone bottomlands in East TX this species is sometimes epiphytic on the often moist lower parts of tree trunks (J. Stanford, pers. comm.). A variety of S. apoda, var. ludoviciana (A. Braun) B.F. Hansen & Wunderlin (based on S. ludoviciana (A. Braun) A. Braun), occurs in the Gulf coastal plain (Hansen & Wunderlin 1998). That variety, which differs in minor ways (e.g., hyaline leaf margins) from var. apoda, is known from GA, FL, AL, MS, and se LA. Selaginella apoda has an interesting biogeography. It is one of numerous TX species that have widespread populations in East TX and isolated disjunct populations on the Edwards Plateau. The range map in Valdespino (1993; and on map provided here) also shows a disjunct occurrence in s TX (which we have not been able to confirm). Even more interesting, it is one of a few species and numerous deciduous forest genera that occur broadly across the eastern United States as far west as TX, and then reappear disjunctly in the mountains of Mexico and in some cases even in Guatemala. [Diplostachyum apodum (L.) Beauv., Lyocopodium apodum L.] (Greek, a-, without, and pous or podium, foot, = footless, in reference to “the stalkless strobili, which were noteworthy in Lycopodium, the genus in which Linnaeus originally place this species”—Thieret 1980)