Common Name: ADDER'S-TONGUE FAMILY
Habit: Perennial herb, small, fleshy, generally glabrous; caudex generally underground, unbranched; roots glabrous with bulblets or plantlets or not. Leaf: generally 1 per caudex per year, divided into 2 facing parts with a common stalk,(0)1 sterile and 1(2) fertile (fertile occasionally aborted); sterile photosynthetic part (trophophore) separated from spore-bearing part (sporophore) at to well above ground level; trophophore simple to compound, veins free and forked or netted with included veinlets; sporophore simple to compound, or 0 in young pls. Sporangia: dehiscent into 2 valves, +- 1 mm wide, thick-walled.
Genera In Family: 10 genera, 80--100 species: +- worldwide, generally rare or overlooked. Note: Distantly related to most (leptosporangiate) ferns. Haploid (gametophyte) generation underground. Both diploid and haploid generations obligately mycorrhizal. The family Psilotaceae (whisk ferns, 2 genera), sister to Ophioglossaceae, is represented in California (SCo) by 1 (of 2 total) apparently introduced species, Psilotum nudum (L.) P. Beauv. Psilotum is easily distinguished by the dichotomously branching, almost leafless green stems, lack of roots, and large (2--3 mm) 3-lobed sporangia; sporangia are borne on the adaxial (upper) side of a minute (+- 1 mm) forked leaf. Pantrop, subtrop (nearest native populations in Arizona and in Sonora, Mexico); expected in cultivation areas, especially at bases of old palms, possibly brought in on root masses as subterranean gametophytes. [Pryer et al. 2004 Amer J Bot 91:1582--1598].
eFlora Treatment Author: Donald R. Farrar, except as noted
Scientific Editor: Alan R. Smith, Bruce G. Baldwin, Thomas J. Rosatti.