Four New Taxa and One Rediscovered Species of Mouriri (Melastomataceae)

Abstract

Three new species of Mouriri from midwestern and southwestern Colombia and eastern Brazil are described and illustrated, as is a new subspecies of Mouriri grandifora from western Amazonia. Mouriri tessmannii, its type and only known specimen destroyed at Berlin, has been recollected and is redescribed and illustrated. Mouriri colombiana Morley, sp. nov. TYPE: Colombia. Antioquia: Municipio de San Luis, Canon del Rio Claro, sector norte, margen derecha, 5?53'N, 74?39'W, 3 June 1984, Alvaro Cogollo 1796 (holotype, COL; isotypes, JAUM, MO). Figure 1. Arbor usque 26 m alta; laminae 2.9-8.6 cm longae, 1.8-3.5 plo longiorae quam latiorae; cryptae stomatophorae nullae, hypodermis absens; pedunculi plerumque 1-flori, pedicelli 0.8-3.5 mm longi; calyx 0.5-0.8 mm findens inter lobos sub anthesi, lobis 1-1.3 mm longis ab staminibus; antherae 3.4-4.1 mm longae, thecae 2.53.3 mm longae, rimis apicalibus dehiscentes; ovarium 1-loculare, ovula 8-11; fructus globosus exterio viscosissimo; semina 1 vel fortasse 2, ca. 22 mm alta, 24 mm lata, 11 mm crassa. Glabrous tree to 26 m high; young twigs rounded. Petioles 3-6 mm long; blades 2.9-8.6 cm long, 1.4-3.8 mm wide, 1.8-3.5 times as long as wide, elliptic to ovate-elliptic or narrowly so, acuminate to abruptly so to caudate at apex, acute and abruptly attenuate at base; midrib grooved above, low-rounded below; lateral nerves slightly visible to invisible above and below when dry; leaves drying dark olive green to black. Midrib xylem open above; stomatal crypts none; upper epidermis one cell thick, lacking mucilaginous walls; hypodermis none; crystals occasional in the upper spongy parenchyma; terminal sclereids stellate with a strong columnar tendency, often with a horizontal central body 2-8 times as long as wide with a columnar extension at each end, sometimes entirely columnar, the columnar parts branching at the epidermis. Flowers axillary and terminal, the peduncles one or two per axil, each 1or rarely 2or 3-flowered, 0.5-4 mm long to base of pedicel measured along the axis with (1)2(-3) internodes in that length; bracts 0.7-1.5 mm long, ovate-triangular, acute, persistent in fruit or deciduous. Flowers pentamerous; true pedicels 0.83.5 mm long; calyx including inferior ovary 4-5 mm long, obconic to campanulate; free hypanthium 2.3-2.5 mm long; calyx lobes before anthesis lowrounded and sometimes with a very small apiculum, 0.2-0.4 mm long, 1.2-1.4 mm wide, 1-1.3 mm long when measured from the stamen attachment, the calyx splitting between the lobes at anthesis a distance of 0.5-0.8 mm, the lobes then 1.7-2.2 mm wide. Petals yellow, 10-11 mm long, 3.5-4 mm wide, narrowly ovate-triangular, acuminate, with a short claw at base. Antesepalous filaments 6.5-7 mm long, antepetalous ones 8-9 mm long; anthers yellow-orange, 3.4-4.1 mm long; thecae 2.5-3.3 mm long, dehiscing by apical slits; gland 0.4-0.8 mm long, 1.3-1.9 mm from apex of anther when measured from center of gland; cauda 0.8-1 mm long. Ovary 1-locular but with a half partition, the ovules technically axile, 8-11; style 13-15 mm long. All flower parts drying blackish except for the anthers. Fruits globose, bearing the remains of the calyx, 23-40 mm diam. when dry, estimated 2750 mm when fresh, then covered with a sticky transparent resin, green to greenish yellow. Seeds 1 or sometimes 2, roughly half spherical, 16-28 mm wide, one studied, this 22.2 mm high, 24 mm wide, 11 mm thick, with an irregular polished area at the base of the outer face 13 mm long by 8 mm wide, the remainder of the outer face irregularly grooved or wrinkled. Distribution. Known only from an area in southern Antioquia, Colombia, about one-third of the way from Medellin to Bogota. Figure 1. Mouriri colombiana Morley. -A. Leaves from various collections. -B. Cleared part of leaf blade showing veins and terminal sclereids. -C. Cross section of leaf blade showing sclereids and upper epidermis. -D. Cross section of leaf midrib. -E. Flowers: a, before anthesis (Renteria 2797); b, at anthesis (Cogollo 1796). -F. Longisection of flower before anthesis. -G. Petal. -H. Anthers, cleared to show veins inside: a, Renteria 2797; NOVON 3: 164-175. 1993. This content downloaded from 157.55.39.15 on Mon, 19 Sep 2016 04:48:08 UTC All use subject to http://about.jstor.org/terms Volume 3, Number 2 Morley 165 1993 Mouriri