An Undescribed Species of Braunia (Hedwigiaceae) from the Andean Cloud Forest

Abstract

Braunia nephelogenes is describedfrom the sub-Andean cloud forest of Ecuador, Peru, and Bolivia. It is easily recognized by its long subulate leaves, narrow sinuose laminar cells, subglobose furrowed capsules, and multicellular spores. This species is epiphytic, unlike most other species in Braunia which are epilithic. The Hedwigiaceae are mainly distributed in montane areas within the tropical regions of the world. The family includes pseudopleurocarpous mosses currently classified in the genera Braunia Schimp. in B.S.G., Hedwigia P. Beauv., Hedwigidium Schimp. in B.S.G., and Pseudobraunia (Lesq. & James) Broth. (De Luna, in prep.). These mosses are usually epilithic, the stems are sympodially branched, and the adventitious branches usually become stoloniferous (De Luna 1990a). The leaves are ecostate and the leaf cells are short-rectangular or elliptic, pluripapillose, and have sinuose walls. The capsules are eperistomate and contain unicellular rugulose spores. After dispersion, the spores germinate forming an exosporic globular protonematal phase (De Luna 1990b). Braunia, as traditionally circumscribed, is a genus of about 20 species with exserted capsules and low blunt leaf cell papillae (cf. Brotherus 1925). We discovered herbarium specimens collected in Ecuador and Peru that share characters found in species in the Hedwigiaceae, particularly those in Braunia. These specimens, however, revealed a unique combination of character states not found in any of the described species in the family. Later, one of us (De Luna) collected additional specimens of the new species in Ecuador and Bolivia. Morphological variation found in seven collections (plus duplicates) available to us was evaluated in relation to the variation found in all other known species in the Hedwigiaceae, as part of an ongoing world-wide taxonomic revision of the family (De Luna, in prep.). This evaluation suggests that these specimens represent a distinct previously undescribed species. BRAUNIA NEPHELOGENES sp. nov. (FIG. 1-9) Sect. Macromidio ob capsulas exsertas sulcatas pertinens; in illa sectione ob folia lanceolata in apicem capillaceum hyalinum gradatim longi-acuminata et ob setam ca. 9 mm longam; urceolum ca. 4 mm supra folia perichaetialia elevatantem notabilis. Plants slender, in stiff, yellow-green to brownish mats; stems creeping to suberect, to ca. 8 cm long, sympodially branched, sympodia 6-20 mm long, adventitious branches erect, flexuose, to 20 mm long, often becoming stoloniferous; stem cross section with 3 rows of small reddish thick-walled cells surrounding 16-22 larger thinner-walled cells, central strand none; axillary hairs uniseriate, with a short rectangular brownish basal cell, and 2-5 hyaline apical cells; leaves erect with spreading to squarrose apices, little altered when dry, narrowly lanceolate, 3.2-3.6 mm long, gradually long-acuminate to subulate, ending in a uniseriate awn, concolorous or sometimes hyaline above, leaf base narrowly decurrent, with 2-3 weak to strong plicae; margins reflexed to recurved in lower 1/4, plane above, bluntly low-crenulate throughout; upper cells long-rectangular to narrowly elliptic, ca. 3-5:1, with sinuose-nodulose vertical walls as thick as or thicker than lumina, horizontal walls straight and much thinner than lumina, pluripapillose with low and blunt curved papillae; basal cells yellow toward insertion, longer and with nearly straight, thick porose walls; cells of decurrencies rectangular; alar cells subquadrate to subcruciform, smooth, ca. 10 cells wide below, extending up margins by ca. 40 cells. Autoicous, sympodia terminated by archegonia or antheridia, usually alternate; perigonial bracts ovate, ca. 1.4 mm long, abruptly acuminate but without a hair point, margins entire, cells at midleaf long-rectangular, thick-walled, porose, smooth, cells at upper shoulders subquadrate in alar-like patches; perichaetial leaves linear-lanceolate, to 6.3 mm long, gradually and slenderly long-acuminate, not hyaline-pointed, licate, margins subentire, cells long-rectangular, to 0007-2745/91/401-403$0.45/0 This content downloaded from 157.55.39.220 on Fri, 02 Sep 2016 04:03:23 UTC All use subject to http://about.jstor.org/terms 402 THE BRYOLOGIST [VOL. 94 003 7j'c m>jI I :3S: