23. Carex L.

Por A.O. Chater.

Perennes. Tallos simples, generalmente foliosos, al menos en la base, generalmente trígonos. Hojas graminiformes, envainadoras en la base; unión de la lámina y vaina con una lígula. Inflorescencia de 2 o más espigas (en Mesoamérica); espigas unisexuales o con flores tanto estaminadas como pistiladas. Flores unisexuales, en espiguillas con una flor, cada una con una gluma escamosa subyacente; perianto ausente. Flores estaminadas con 2 o 3 estambres. Flores pistiladas encerradas en un utrículo (perigonio) firme, nervado, del que se proyectan 2 o 3 estigmas. Aquenios lenticulares o trígonos. Más de 2000 spp. Cosmopolita.

Mientras este volumen estaba en prensa, Reznicek (1990) citó para Chiapas las dos siguientes especies: Carex pubigluma Reznicek y C. hultenii Aspl., las que se agregan a la flora.

Bibliografía: Hermann, F.J. Agric. Handb. 467: 1-219. (1974). Reznicek, A.A. Syst. Bot. 11: 56-87 (1986).

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CAREX L.

Por Robert Kral

Cespitosas o rizomatosas, perennes; culmos mayormente angulados; plantas monoicas o raramente dioicas. Hojas mayormente lineares, planas, dobladas o acanaladas; vaina cerrada, variadamente ligulada. Flores estaminadas y pistiladas en la misma espiga o en espigas diferentes en la misma planta; espigas frecuentemente abrazadas por una bráctea foliosa, sésiles o variadamente pedunculadas, flósculos individuales abrazados por una sola escama paleácea; perianto ausente; estambres 3; ovario, excepto por el ápice del estilo y el fruto, rodeado laxa o estrechamente por una bráctea modificada en forma de saco, que es el periginio, éste con o sin rostro.

El género más grande de la familia, con más de 2000 especies, cosmopolita, distribuido principalmente en climas fríos y húmedos, en Centroamérica principalmente confinado a los bosques de zonas altas; 5 especies en Nicaragua.

F.J. Hermann. Manual of the genus Carex in Mexico and Central America. Agric. Handb. 467: i–219. 1974.

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Plantas perennes; culmos simples, foliosos y gene-ralmente trígonos. Hojas con una lígula en la unión dela lámina y la vaina. Infl. de 2 ó más espigas unisexua-les o bisexuales; brácteas foliosas. Espiguillas de 1 fl. Fls. unisexuales, sin perianto, pero con una gluma es-camosa subyacente, las pistiladas encerradas en una bráctea (periginio) firme y nervada; estambres (fls.estaminadas) 2 ó 3; estigmas (fls. pistiladas) 2 ó 3, exertos. Frs. (aquenios) lenticulares o trígonos.

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Herbs, perennial; rhizome usually stoloniferous. Culms tufted or sparse, lateral or central, erect, trigonous, bladeless sheathed at base. Leaves basal or basal and cauline, flat, rarely involute or revolute on margins, linear or lorate, rarely lanceolate, sheathed at base. Involucral bracts leaflike, rarely scale-shaped or setaceous, sheathed or not. Flowers unisexual, 1 male flower or 1 female flower in a unisexual spikelet, female spikelet included by prophyll, prophyll wholly connate at margins into utricle, sometimes reduced spikelet axis present in utricle, with scalelike bractlet at base. Spikes 1 to numerous, usually numerous spikes arranged in spicate, racemose, or paniculate inflorescence, composed of many unisexual or bisexual spikes, bisexual spike androgynous or gynaecandrous, usually plants monoecious, rarely dioecious, pedunculate or sessile, with or without sheathlike or utriculiform cladoprophyll at base; male flower with (2 or)3 stamens, filaments distinct; female flower with 1 pistil, style slightly slender, persistent or deciduous, base usually not thickened; stigmas 2 or 3. Utricles trigonous, plano-convex or biconvex, with slightly long or short beak. Nutlets rather tightly or loosely enveloped in utricle, trigonous or plano-convex.

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Herbs, perennial, cespitose or not, rhizomatous, rarely stoloniferous. Culms usually trigonous, sometimes round. Leaves basal and cauline, sometimes all basal; ligules present; blades flat, V-shaped, or M-shaped in cross section, rarely filiform, involute, or rounded, commonly less than 20 mm wide, if flat then with distinct midvein. Inflorescences terminal, consisting of spikelets borne in spikes arranged in spikes, racemes, or panicles; bracts subtending spikes leaflike or scalelike; bracts subtending spikelets scalelike, very rarely leaflike. Spikelets 1-flowered; scales 0–1. Flowers unisexual; staminate flowers without scales; pistillate flowers with 1 scale with fused margins (perigynium) enclosing flower, open only at apex; perianth absent; stamens 1–3; styles deciduous or variously persistent, linear, 2–3(–4)-fid. Achenes biconvex, plano-convex, or trigonous, rarely 4-angled. x = 10.

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"Fls unisexual, without perianth, borne in spikes, each fl solitary in the axil of a scale; spikes unisexual or bisexual, when bisexual the staminate fls usually either termina(spikes androgynous) or basal (spikes gynaecandrous); stamens (2)3; pistillate fls individually enclosed by a sac-like scale (the perigynium), from the mouth of which the style or stigmas protrude, as well as being subtended by the open pistillate scale; stigmas 2 or 3, the achene accordingly lenticular or trigonous; grass-like perennial herbs with 3-ranked lvs, closed sheaths, and triangular or terete, mostly solid stems, the lower sheaths bladeless (plants aphyllopodic) or with ± well developed blade (plants phyllopodic); spikes solitary and terminal, or much more often racemosely arranged in a terminal infl that is rarely again branched, sometimes some of them well removed from the others and axillary to lvs near the base. 1500+, cosmop., especially in moist North Temperate and Arctic regions.Some spp. of subg. Primocarex have a definite rachilla alongside the achene within the perigynium, showing that each pistillate fl represents a branch of an infl that has been reduced to a single fl. The perigynium is a highly modified bract on the adaxial side of this short, uniflorous branch. The bract wraps around the pistillate fl, and its margins are connate so that the fl is enclosed in a sac with a minute apical opening. In two of the four subgenera (Primocarex and Vignea) the line of fusion of the bract-margins can be seen as a suture or imperfection toward the tip of the dorsal side of perigynium. The side of the perigynium next to the pistillate scale is called the dorsal side, and the side next to the axis of the spike is called the ventral side. Many of the characteristically tristigmatic spp. of Carex occasionally have a few distigmatic fls intermingled; such specimens should be keyed as tristigmatic."

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SELECTED REFERENCES

Bernard, J. M., and L. Soukupová, eds. 1988. Studies in wetland carices of the temperate zone. Aquatic Bot. 30: 1–168. Catling, P. M., A. R. McElroy, and K. W. Spicer. 1994. Potential forage value of some eastern Canadian sedges (Cyperaceae: Carex). J. Range Managem. 47: 226–230. Catling, P. M., A. A. Reznicek, and W. J. Crins, eds. 1990. Systematics and ecology of the genus Carex (Cyperaceae). Canad. J. Bot. 68: 1405–1472. Cayouette, J. and P. M. Catling. 1992. Hybridization in the genus Carex with special reference to North America. Bot. Rev. (Lancaster) 58: 351–438. Chater, A. O. 1980. Carex. In: T. G. Tutin et al., eds. 1964–1980. Flora Europaea. 5 vols. Cambridge. Vol. 5, pp. 290–323. Egorova, T. V. 1999. Sedges (Carex L.) of Russia and Adjacent States within the Limits of the Former USSR. St. Petersburg and St. Louis. Hermann, F. J. 1970. Manual of the Carices of the Rocky Mountains and Colorado Basin. Washington. [Agric. Handb. 374.] Hudson, J. H. 1977. Carex in Saskatchewan. Saskatoon. Kreczetowicz, V. I. 1936. Are the sedges of subgenus Primocarex Kük. primitive? Bot. Zhurn. S.S.S.R. 21: 395–425. Kükenthal, G. 1909. Cyperaceae–Caricoideae. In: H. G. A. Engler, ed. 1900–1953. Das Pflanzenreich…. 107 vols. Berlin. Vol. 38[IV,20]. Nelmes, E. 1952. Facts and speculations on phylogeny in the tribe Cariceae of the Cyperaceae. Kew Bull. 1951: 427–436. Reznicek, A. A. 1990. Evolution in sedges (Carex, Cyperaceae). Canad. J. Bot. 68: 1409–1432. Roalson E. H., J. T. Columbus, and E. A. Friar. 2001. Phylogenetic relationships in Cariceae (Cyperaceae) based on ITS (nrDNA) and trnT-L-F (cpDNA) region sequences: Assessment of subgeneric and sectional relationships in Carex with emphasis on section Acrocystis. Syst. Bot. 26: 318–341. Robertson, A. 1984. Carex of Newfoundland. St. John’s. Smith, D. L. and J. S. Faulkner. 1976. The inflorescence of Carex and related genera. Bot. Rev. (Lancaster) 42: 53–81. Starr, J. R., R. J. Bayer, and B. A. Ford. 1999. The phylogenetic position of Carex section Phyllostachys and its implications for phylogeny and subgeneric circumscription in Carex (Cyperaceae). Amer. J. Bot. 86: 563–577. Yen, A. C. and R. G. Olmstead. 2000. Molecular systematics of Cyperaceae tribe Cariceae based on two chloroplast DNA regions: ndhF and trnL intron-intergenic spacer. Syst. Bot. 25: 479–494. Yen, A. C. and R. G. Olmstead. 2000b. Phylogenetic analysis of Carex (Cyperaceae): Generic and subgeneric relationships based on chloroplast DNA. In: K. L. Wilson and D. A. Morrison, eds. 2000. Monocots: Systematics and Evolution. Melbourne. Pp. 602–609.

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