[taxon report][distribution map][all photos][line drawing]
Scientific Name: Fissidens littlei (Williams) Grout
Synonyms: Moenkemeyera littlei R.S. Williams
Vernacular Name: Little’s fissidens
R-E-D Code: 3-3-3
Description: Acrocarpic moss to 3 mm tall and 2 mm wide, the stems not or sparingly branched; central strand absent; leaves distichous, equitant, consisting of 2 laminae that clasp the stem, arranged on edge to the stem and split at the base, to 1.5 mm long and 0.25 mm wide, as many as 8 pairs on the stem, not crisped upon drying; vaginant laminae 1/2 to 2/3 the leaf length; margins crenulate, elimbate; costae ending 3-5 cells before leaf apex; cells of the laminae 1-stratose, mammillose, irregularly quadrate to hexagonal, oblate on the margins, 8-10 µm long/wide; sporophytes 1 per perichaetium; setae 1.4-1.8 mm long; capsules erect, symmetrical, to 0.5 mm long; peristome single, the teeth 16, undivided, papillose; operculum to 0.3 mm wide; calyptra cucullate, smooth, about 0.3 mm wide; spores 8-11 µm.
Similar Species: Fissidens sublimbatus Grout is rather common on nearby bluffs, both gypsiferous and not: its leaves usually have an easily noticeable limbidium on the margins (absent in littlei), and its cells lack a mammilose, nipple-like projection (present in littlei).
Distribution: New Mexico: central Dońa Ana County.
Habitat: Vertical and circular walls of shaded gypsum sink holes and bluffs, 1300 m (4350 ft).
Remarks: This moss is known from only one site and two collections 63 years apart: the original collection was in 1935 (by Elbert L. Little, Jr.) from gypsum plains of the Jornada Experimental Range, USDA-ARS; a second collection was in 1998 at the same site (by Kelly W. Allred). The 1935 collection was from the sides of vertical gypsum walls as much as 8 ft high. The 1998 collection was from the shaded walls of small sink holes that resembled small animal burrows. A return trip to the same site in 2014 failed to find the moss.
The name Fissidens orcuttii Grout has been incorrectly associated with this species, but it belongs to F. amoenus Muller Hal., which is not known from New Mexico.
Conservation Considerations: The gypsum bluffs and sink holes are easily eroded by hard rainfall. The area is also frequented by domestic livestock, as there is a watering tank nearby. Their scrambling into and out of the depressions readily crumbles and corrodes the banks and walls.
Important Literature (*Illustration):
*Purcell, R.A. 2007. Fissidens, pp. 331-357. IN: Flora of North America, vol. 27. Oxford Univ. Press.
Little, E.L. Jr. 1937. Bryophytes of the Jornada Experimental Range, New Mexico. The Bryologist 40: 81-83.
Allred, K.W. 1998. Second collection of a little moss, Fissidens littlei (Williams) Grout, rediscovered from a little sinkhole in New Mexico. Evansia 15(4): 148-149.
*Williams, R.S. 1936. Moenkemeyera littlei sp. nov. The Bryologist 39: 40-41.
Information Compiled By:
Kelly W. Allred, 2017