Cochlidium

  • Authority

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

  • Family

    Polypodiaceae

  • Scientific Name

    Cochlidium

  • Description

    Genus Description - Small epiphytes; rhizomes ascending to short-creeping; rhizome scales orangish to tan, concolorous, linear-lanceolate, entire or nearly so; fronds clumped; stipes not articulate; blades undivided or occasionally furcate, firm, chartaceous to subcoriaceous, glabrous or with scattered minute catenate hairs, lacking reddish brown setae, margins entire or sinuate; veins obscure or occasionally visible, simple or forked, sometimes united to form costal areoles without free veinlets; sori either linear, consisting of a line of sporangia borne in a medial groove and immersed or superficial, or sori intermittent or round and borne at the base of lateral veins, often confluent at maturity; indusia and paraphyses absent; sporangia glabrous with vertical annulus; spores green, tetrahedral-globose; x=33, 34?, 35 (counts of 2n=ca. 148, based on 37, are now thought to be erroneous).

  • Discussion

    Type: Cochlidium graminoides (Sw.) Kaulf. [= Grammitis graminoides Sw.]; also see Bishop, 1978.

    Xiphopteris Kaulf., Berlin. Jahrb. Pharm. Verbundenen Wiss. 21: 35. 1820. Lectotype (chosen by J. Sm., Hist. Fil. 179. 1875): Xiphopteris serrulata (Sw.) Kaulf. [= Acrostichum serrulatum Sw.]. For additional synonymy, see L. E. Bishop (1978).

    According to Bishop (1978), Cochlidium comprises 16 neotropical species, one of which extends into Africa and adjacent islands; these are included in Grammitis by some workers. Three species of Cochlidium are found in Mexico, where they grow in montane rain forests. The type of Xiphopteris, X. serrulata, has been placed in Grammitis s.l. by numerous authors, but Bishop (1978) included X. serrulata in Cochlidium on the basis of the pale concolorous scales, lack of branched trichomes, a stellar type similar to that of Cochlidium, and the conduplicate nature of the fertile region. He believed that the almost-fused nature of the receptacles suggested a derivation from a coenosoral ancestor, although the series suggests to us a trend in the opposite direction (separate sori to coenosori) with equal or greater justification. Preliminary molecular data suggest that Cochlidium is monophyletic (Ranker et al., 2004) and the sister group to the blackmargined, simple bladed species of Grammitis (Grammitis s.str.) allied to the group of G. bryophila (Maxon) F. Seym. in the Neotropics; this group also includes several closely related species in East Africa and Madagascar to Polynesia. The clade Grammitis s.str. plus Cochlidium, in turn, appears to be the sister group of the peculiar endemic Hawaiian genus Adenophorus (Ranker et al., 2003)