New Tropical American Species of Sphagnum

Abstract

Described as new: Sphagnum imperforatum (Colombia), S. subdivisum (Costa Rica), S. cleefii (Colombia), S. trirameum (Costa Rica), and S. poasense (Costa Rica). Continued study of the genus Sphagnum in Latin America demonstrates that not enough names have been provided to account for a sizable flora in a genus not very well understood in any part of its range. In this paper, descriptions and illustrations are provided for five species. SPHAGNUM (sect. SPHAGNUM) IMPERFORATUM, sp. nov. (FIG. 1-8) Plantae parvae, dense caespitosae, fuscae. Hyalodermis caulis stratis duobus; parietes cellularum superficialium exteriores epidermis caulinae poris 1-2, fibris spiralis nullis. Folia caulina late ovata, apice rotundo-cucullata, marginibus lateralibus non limbatis, sulco resorptio instructis; cellulae hyalinae fibrosae, saepe 1-divisae, dorso poris 48, ellipticis, annulatis ad commissuras dispositis instructae, superficie interiore poris 1-4 magnis, rotundis, non annulatis sitis. Fasciculi ramorum ramis 3. Folia ramorum ovata, cucullato-concava, marginibus sulco resorptio instructis; cellulae hyalinae dorso pseudoporis magnis, ellipticis, annulatis, in angulis instructae, superficie interiore pseudoporis 5-9 ? parvis ad commissuras sitis; cellulae chlorophylliferae utroque latere folii anguste liberae. Plants small, densely tufted, tawny-brown. Cortical cells of stem in 2 layers, epidermal cells 1-2porose, without fibrils; wood cylinder dark-brown. Stem leaves 1.5 mm long, broadly ovate, deeply cucullate-concave, slightly roughened at back of tip and denticulate-bordered by a resorption furrow; hyaline cells fibrillose throughout, often 1-divided, on outer surface with 4-8 large, ringed, elliptic commissural pores, those at adjacent angles in 3's, on inner surface with 1-4 large, thin-margined, round pores. Branches in fascicles of 3 (2 spreading); cortical cells 1-porose, without fibrils. Branch leaves 1.3-1.6 mm long, ovate, deeply concave, roughened at back of cucullate apex, bordered by a resorption furrow; hyaline cells somewhat convex on both surfaces, more so on outer, on outer surface with large, ringed, elliptic pseudopores (or rarely pores) in 3's at adjacent angles, on inner surface with 5-9 rather small, ringed commissural pseudopores of various shapes and sizes; green cells in section central and elliptic but narrowly exposed on both surfaces because of thickened end walls, somewhat more broadly exposed on inner surface. TYPE. Colombia: Antioquia, mpio. Carmen del Viboral, Vereda La Milagrosa, via El Canada, Finca La Soledad, ca. 6?5'N, 75?25'W, 2,400-2,600 m alt., Quercus, Weinmannia, Hedysomum, Befaria cloud forest, common at summit, James L. Luteyn & Ricardo Callejas 11798, 27 Oct. 1987 (holotype, NY; isotype, MICH). The stem leaves are much like branch leaves in being cucullate-concave, bordered by a resorption furrow, and fibrillose and porose throughout, but the branch leaves have pseudopores rather than actual perforations. On the outer surface of hyaline cells of branch leaves are large, ringed, elliptic pseudopores conspicuously grouped in 3's at adjacent angles. On the inner surface the pseudopores are quite numerous; they are variable in size an shape, have ringed margins, and are arranged along the commissures. The leaf section is imilar to that of S. perichaetiale Hampe, but the branch leaves have an abundance of pseudopores of a commissural position on the inner surface. SPHAGNUM (sect. ACUTIFOLIA) SUBDIVISUM, sp. nov. (FIG. 9-16) Plantae molles, pallide puniceae. Parietes cellularum superficialium exteriores caulinae non porosi. Folia caulina oblongo-triangula, anguste limbata; cellulae hyalinae dorso parte superiore fibris rudimentariis, plerumque multidivisae, lacunis membranaceis 1-3 instructae, interiore superficie membrana resorpta. Folia ramulina late oblongo-lanceolata, anguste limbata; cellulae hyalinae dorso valde convexae, poris 4-6 ellipticis, annulatis ad commissuras sitis instructae, superficie interiore pseudoporis 5-9, ? parvis, annulatis; cellulae chlorophylliferae triangulae, interiore foliorum liberae. Plants soft, pale-pinkish or violet-pink. Epidermal cells of stem without pores. Stem leaves 1.7 mm long, oblong or oblong-triangular, concave, acute or apiculate, narrowly bordered all around; hyaline cells in upper quarter of leaf weakly fibrillose with a slight development of membrane pleats, consistently 1-several times divided, on outer surface with 1-3 rounded to oblong membrane gaps in each cell compartment, on inner surface largely resorbed or with a few rounded gaps and some membrane pleats. Branch leaves 1.4-1.6 mm long, broadly oblong-lanceolate and concave-acuminate, bordered 0007-2745/89/98-104$0.85/0 This content downloaded from 207.46.13.117 on Sun, 23 Oct 2016 04:34:59 UTC All use subject to http://about.jstor.org/terms 1989] CRUM: TROPICAL AMERICAN SPHAGNUM 99