Asplenium delicatulum C.Presl

  • Authority

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

  • Family

    Aspleniaceae

  • Scientific Name

    Asplenium delicatulum C.Presl

  • Description

    Species Description - Roots filiform, proliferous and giving rise to new plantlets at long intervals (thus forming colonies); rhizomes suberect; rhizome scales brown, clathrate, obtuse at tips, concave on inner (adaxial) surfaces, 0.5–1 x 0.1–0.3 mm, entire; fronds tightly clustered, 5–15 cm long; stipes brownish green, dull, 1–4 cm x0.3–0.5 mm, 1/4–1/3 of frond length, glabrous, with wings 0.1 mm wide; blades membranaceous, 3–6 x 1.5–2.5 cm, 2–3-pinnate, narrowly deltate, widest at bases, apices pinnatifid, not proliferous; rachises greenish, glabrous, with narrow greenish wings 0.1 mm wide; pinnae 4–6 pairs, 1–1.5 cm long, stalked to 2 mm, ultimate segments linear or narrowly elliptic, 0.5–0.8 mm wide, often notched or bifurcate at tips; veins evident, simple, tips evident adaxially; indument abaxially of scattered, appressed, whitish to tan, clavate hairs 0.1 mm long; sori 1 per ultimate segment and usually located at bases of segments near bifurcation of veins; indusia 1–1.5 x 0.5–0.6 mm, margins erose; spores reniform.

  • Discussion

    Type. Ecuador. “in Cordilleris Quitensibus,” Haenke s.n. (PRC; isotype HBG, photos F, GH, US).

    Asplenium delicatulum is most similar to very small forms of A. cuspidatum and differs by its much smaller size, thinner blade texture, proliferous roots that produce new plantlets, and very small, ovate, more or less appressed and inrolled rhizome scales. Another close relative is A. tenerrimum, which differs in the more broadly deltate blades, darker, more polished stipe bases, and linear-lanceolate rhizome scales. Throughout its range, A. delicatulum occurs only at relatively low elevations, below 1000 m. Asplenium cuspidatum Lam. var. triculum Lellinger (Proc. Biol. Soc.Wash. 98: 367. 1985. Type. Costa Rica. San Jose´: Basin of El General, Skutch 4776, US; isotypes F, G) is also very similar to this species and differs primarily by having fronds not borne at intervals along thread-like roots, larger and less dissected blades, and patent pinnae.

  • Distribution

    On rocks along streams; 300–950 m. Mexico; Guat, Hond, Nic, CR, Pan; Ec, Peru. Also reported from Cuba, Hispaniola, Colombia, Venezuela, Chile, and Argentina by Adams (in Davidse et al., 1995), but the species is circumscribed differently by him; Asplenium delicatulum is not included for Chile by Marticorena and Rodríguez (1995).

    Cuba South America| West Indies| Chile South America|