Gerritea, a New Genus of Paniceae (Poaceae: Panicoideae) from South America Fernando O. Zuloaga and Osvaldo Morrone Instituto de Botinica Darwinion, Casilla de Correo 22, San Isidro, 1642, Argentina Timothy Killeen Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166, U.S.A.ABSTRACT. Gerritea pseudopetiolata of the tribePaniceae is described and illustrated. Leaf anatomyof this new genus is also included, and relationshipswith related genera within the Paniceae are dis-cussed. During fieldwork carried out by T. Killeen in1987, a previously unknown grass was collected atmid elevation in Bolivia, Department La Paz, be-tween Coroico and Caranavi. Additionally, new spec-imens, previously collected by S. Beck, were foundin the herbarium of LPB.Gerritea pseudopetiolata Zuloaga, Morrone & Killeen, gen. et sp. nov. TYPE: Bolivia. La Paz: Nor Yungas on road between Caranavi and Coroico, 1600'S, 67030'W, 800 m, 25 July 1987, T. Killeen 2632 (holotype, ISC; isotypes, F, LPB). Figures 1, 2. Gramen perenne, caespitosum; culmis supra nodis pro-fuse ramificantibus, 60-120 cm longis; nodis pilosis. Fo-liorum vaginae pilosae vel glabrae, 4-17 cm longae. Lig-ula inferne membranacea, superne ciliata, 0.3 0.6 mmlonga. Lamina lineari-lanceolata, 11-27 cm longa, 0.71.5 cm lata, decidua; pseudopetiolo usque 2 cm longo,piloso. Inflorescentiae paniculatae, laxae, diffusae, 14 30cm longae, 4 12 cm latae. Spiculae ellipsoideae, 1.82.2 mm longae, 0.5 mm latae, longe pilosae; quarn gluinainfera -/ longitudino spiculae aequans, pilosa, 3-nervia;gluma supera 3-nervia. Anthoecia infera neuter: lemmainfera 3-nervia; palea infera 0.7-1 mm longa. Anthoeciasupera bisexualia, ellipsoidea, 1.3-1.5 mm longa, 0.4 mmlata, membranacea, decidua, glabra; lemma 3-nervia, pa-lea 2-nervia. Lodiculae 2, conduplicatae, glabrae. Stamina3. Caespitose perennial. Culms rigid, many noded,procumbent, 60-120 cm long, profusely branchingat the upper nodes, internodes 4-9 cm long, finelystriate, cylindric, pale or tinged with purple, denselypilose toward the distal portion with whitish, ap-pressed hairs; nodes pilose, covered with whitish,long hairs. Leaves mostly cauline. Sheaths longerthan the internodes, 4 17 cm long, greenish ortinged with purple, strongly keeled, glabrous ordensely papillose-pilose, the margins membranous,ciliate; lower sheaths usually laciniate; auricles small,pilose. Ligules 0.3 0.6 mm long, membranous-cil-iate, pilose on the abaxial surface, glabrous on theadaxial surface; collar pilose or glabrous, well definedwith a transverse brownish line. Blades linear-lan-ceolate, 11 27 cm long, 0.7 1.5 cm wide, flat, witha long pseudopetiole up to 2 cm long, articulatedat the base and early deciduous, sparsely pilose, themargins scaberulous, the lower ones ciliate with longwhitish hairs or glabrous. Peduncle terete, up to 10crn long, hirsute. Inflorescence a terminal, exserted,panicle, lax, pyramidal, multiflowered. 14 30 cmlong, 4-12 cm wide; main axis flexuous, hispid,greenish or tinged with purple; pulvini pilose, first-order branches divergent; axis of the branches sca-brous, sparsely hispid; pedicels up to 8 mm long,flexuous, scaberulous, sparsely pilose, terete. Spike-lets solitary, ellipsoid, 1.8-2.2 mm long, 0.5 mmwide, slightly laterally compressed, gaping, greenishor tinged with purple, hispid; upper glume and lowerlemma subequal, 3-nerved. Lower glurne lanceolate,1.4-1.9 mm long, :/ to '/ the length of the spikelet,with papillose-pilose hairs up to 7 mm long towardthe margins, acuminate, 3-nerved, with a stipe 0.2mm long below its insertion. Ipper glurne 1.8-2mm long, herbaceous, acute, papillose-pilose towardthe margins with whitish hairs up to 7 mm long.Lower lemma 1.6-1.7 mm long, glumiform, acute,glabrous. Lower palea ovate-lanceolate, 0.7-1 mmilong, 0.1-0.2 mm wide, membranous, hyaline, themargins scaberulous, 2-nerved; lower flower absent.l'pper anthecium narrowly ellipsoid, 1.3 1.5 mmlong, 0.4 mm wide, glabrous, membranous, smooth,pale, disarticulating at maturity; lemma 3-nerved,the margins flat, not enrolled over the palea; palea2-nerved, free at its apex; lodicules 2, conduplicate,truncate, 0.2 mm long, embracing the lower marginsof the palea; stamens 3, anthers 0.6-0.7 mm long;styles 2, free; stigmas plumose, whitish. Caryopsisnot seen.NOvoN 3: 213-219. 1993.
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