Fissidens hallianus (Sull. & Lesq.) Mitt.

  • Authority

    Buck, William R. 1987. Bryostephane Steereana: A Collection of Bryological Papers Presented to William Campbell Steere On The Occasion of His 80th Birthday. Mem. New York Bot. Gard. 45: 1-749.

  • Family

    Fissidentaceae

  • Scientific Name

    Fissidens hallianus (Sull. & Lesq.) Mitt.

  • Description

    Species Description - Leaves usually small and scale-like proximally, increasing in size upward, those of the perichaetia longest, to about 6.5 mm long and 0.7 mm wide; margins elimbate or limbate in the proximal 2/3 or less of the vaginant laminae; costae ending 5-15 cells below the leaf apices; vaginant laminae 1/4-1/3(-1/2) the leaf length, unequal, in most leaves the minor lamina of each pair rounded distally and attached only at the costa or very near the costa, in the lower leaves the lesser laminae end near the leaf margins; dorsal laminae usually ending above the insertion; laminal cells, other than those ofthe costae, 10-15 µm long X 9-11 µm wide. Perigonia terminal on elongated axillary branches. Perichaetia terminal on main stems and elongated axillary branches. Sporophytes rather common, 1(-2) per perichaetium; setae 0.7-1.5 mm long, often bent at the vaginulae; thecae (0.40-)0.60-0.80 mm long; peristome teeth undivided and often lacunate to divided for about 2/3 their length, even in the same capsule, nearly smooth to papillose below, the prongs with perpendicular and spiral thickenings or striations; opercula conic-rostrate, 0.40-0.60 mm long. Spores (14-)18-22(-32) µm in diam. Calyptrae not seen.

  • Discussion

    Conomitrium hallianum Sull. & Lesq. in Aust., Musci Appalachiani 108b. 1870; C. hallii Sull. & Lesq. ex Sull., Icones Muse. Suppl. 43, Tab. 28. 1874, nom. illeg.; Octodiceras hallianum (Sull. & Lesq. in Aust.) Jaeg., Ber. Thatigk. St. Gallischen Natiirwiss. Ges. 1874-75: 136. 1876. Type: UNITED STATES. Illinois: Menard Co., on decayed wood in a well, Athens, E. Hall, Sullivant & Lesquereux, Musci Appalachiani 108b (holotype FH-Sull!; isotypes BM!, FH- Sull!, NY!, PAC!). N.B.: Additional packets in mo and NY, collected by Hall, are labelled "Athens, Illinois," and probably represent portions of the original material.

    Illustrations: Figures 15-22.

    Fissidens manateensis Grout in Holz., Musci Acrocarpi Boreali—Americani et Europei 590.1926. Type: UNITED STATES. Florida: Manatee Co., on log in creek beside rd. from Oneca to Vema, 9 Mar 1926, A. J. Grout s.n. (holotype duke!; isotypes Holzinger's Musci Acrocarpi Boreali-Americani et Europei 590 DUKE!, MICH!, MO!).

    This species, endemic to the United States, has been confused with F. fontanus. However, the two species are distinct morphologically and reproductively. Both species have vaginant laminae that are similar in length and form, but the costae in F. hallianus end much closer to the leaf apices than the costae in F. fontanus. Sporophytically, the two species are quite easily separated. The sporophytes of F. hallianus are terminal as opposed to the typically lateral ones of F fontanus. Reese (1984) is the only North American author to have used this as a distinguishing character. Moreover, the setae are longer, relative to the length ofthe capsules. Additionally the peristome teeth differ profoundly. While the peristome teeth in F. fontanus are incomplete and often truncate, those of F. hallianus are complete, and either divided or undivided, even within the same capsule. Fissidens manateensis, although compared to F. fontanus in its protologue, differs from F. hallianus only in having undivided peristome teeth. Specimens examined from Florida (Redfearn 2060) and Louisiana (Haynes 2991) contain sporophytes in which the peristomes consist of both divided and undivided teeth so that maintaining F manateensis distinct from F. hallianus is no longer tenable.

    The probable reproductive isolation and thus the integrity of F. fontanus and F. hallianus are reflected by collections (Haynes 2991 and Reese & Lemmon 6364) made in Louisiana. In these collections both species are present. Not only are the gametophytic differences maintained, but no intermediates in sporophyte size and peristome teeth were observed.

  • Distribution

    Massachusetts, New Jersey, Illinois, North Carolina, Florida, Louisiana and Texas). The species appears to be quite common in Louisiana and probably is also in other Gulf states.

    United States of America North America|