COMUNICA CIONES Rev. Bio!. Trop., 35(1): 147-149, 1987

Na rdus stricta and Eleusine multiflora (Gramineae), new to Mesoamerica

Richard W. Pohl Professor of Botany, Curator of the Herbarium, Dept. of Botany, lowa State University, Ames, la . 50011, E.E.U.U.

(Received April 14, 1986)

Resumen: Nardus stricta L. se encuentra en el volcán Turrialba, Costa Rica, acompañado por varias especies de gramineas europeas. Eleusine multiflora Hochst ex A. Rich. , una especie africana, fue colectada en Jalisco y Chiapas, México.

' Nardus strieta L. is a common grass of boreal culiar inflorescence and and the ano­ and Greenland, occurring also as a ca­ malous leaf anatomy, the systema tic position of sual introduction in the northern United States Nardus has been interpreted variously. The ge­

and Canada. It has not previously been found in nus has been assigned to the ( = Fes­ Central America. The collection listed below tucoideae) by Pilger (1954) and by Stebbins represents its flrst known occurrence in Costa and Crampton (1961). Tateoka (1957) placed it Rica. A number of alpine grasses from Europe in the . While various chromo­ occur in similar habitats on the volcanoes of the sorne numbers have been reported fo r Nardus, Cordillera Central. Probably they represent sur­ the usual count is 2n= 26, with other numbers vivals from early introductions of mixtures of up to 2n=30 also having been reported. Any of European pasture grasses which were imported these numbers would be highly anomalous in to provide forage fo r dairy cattle. Among this the Pooideae. group of waifs are such species as Agrostis gi­ Leaf blade cross-sectional anatomy is highly gantea Roth, A. stolonife ra L., var. palustris xeromorphic. The densely packed mesophyll (Ruds.) Farwell, A. tenuis Sibth., Aira ea/yo­ and the evidence of an outer bundle sheath phyllea L., Anthoxanthum odoratum L., Cy­ with empty cells suggests that Nardus belongs nosurus eris tatus L., Briza minor L., Dan­ to the Arundinoideae. Both leaf epidermes thonia deeumbens (L.) Lam. & DC., Festuea show bicellular microhairs with equal cells, the arundinaeea Sehreb., F ovina L., F rubra L., F terminal one being pointed, a fe ature which tenuifo lia Sibth., Glyeeria plieata (Fries) Fries, would also exclude Nardus from the Pooideae. Holeus lanatus L., Poa annua L., P. pratensis L., Stomata are present only on the adaxial surface P. trivialis L., Vulpia bromoides (L.) S.R. Gray, of the blade and are broadly oval in contrast to V. myuros (L.) K. GmeL, var. harsuta Rack. the oblong stomatal complexes of the Pooideae . Nardus strieta fonns dense tufts, arising The lower surface shows silico-suberized cou­ from a very short rhizome. The foliage is pIes, which is normally a pooid fe ature, and mostly basal, and the blades are very narrow, highly lignified single-celled macrohairs. On the wiry, and folded. The inflorescence is very slen­ basis of available morphological and cutological der and spicate, with two rows of erect spike­ evidence, Nardus appears to be a very isolated lets borne on two sides of the triquetrous , but best assigned to the Subfamily rachis, usually appressed to, the shallow cavities Arundinoideae. The only known Central Ame­ of the rachis. The glumes are reduced to a mi­ rican collection is the following: nute rigid cupule, from which the single awned Costa Rica: Prov. Cartago: In upper pastu­ floret disarticulates (Fig. 1). Because of the pe- res, Volcán Turrialba, alt . 3000-3300 m. Wes-

147 148 REVISTA DE BIOLOGIA TROPICAL

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Fig. 1. Nardus stricta. A habit, B. portion of spike, dorsal view, showing winged, dentate rachis, C. . Scale line for spikelet = 1 mm. Scale line for spike = 5 mm. ton & Kincaid 4950, 5 June 1967 (ISC). milar to the pantropical Eleusine indica (L.) Eleusine multiflora Hochst. ex A. Rich., an Gaertn., differing in the short, thick spikes, less African member of the Subfami1y Chloridoi­ than 2 cm long, and in the flattened, winged deae, has only recently been found in the rachis which is marginal1y dentate (Fig. 2). Two western hemisphere. lt has been reported from recent collections from México, cited below, Mexico by McVaugh (1983). This species is si- suggest that it is becoming more common and POHL: Nardus stricta and Eleusine multifiora new to Mesoamerica 149

hg. 2. Eleusine multifiora. A. habit . B. single spike, dorsal view, showing winged, dentate rachis, C. spikelet. Scale line for spikelet = 1 mm. Scale line for spike = 5 mm.

may eventually be found in Central America. Pilgcr, R. 1954. Das System der Gramineae. Bot. México: Chiapas: San Cristobal las Casas, Jahrb . 76 : 281-334.

elevo 7100 ft. Breedlove & Raven 8266, (US); Stebbins, G. L. & B. Crampton. 1961. A suggested Jalisco: 15 km s.w. of Matanzas, 2100 m, Luna revision of the grass genera of Temperate North 4455 (ISG). Amcrica. Recent Advances in Botany 133-145.

REFERENCES Tatcoka, T. 1957. Miscellaneous papers on the phylo­ geny of (10). Proposition of a new phylo­ McVaugh, R. 1983. l:lora Novo-Galiciana, Vol 14 gcnetic of Poacear. J. Jap. Bot. 32: 275-287. (Gramincac) . Univ. of Michigan Press.