versión On-line ISSN 1850-1699
Darwiniana v.45 n.2 San Isidro ago./dic. 2007
Carex sagei (Cyperaceae), the correct name for C. barrosii
Gerald A. Wheeler
University of Minnesota Herbarium, Bell Museum of Natural History, St. Paul, Minnesota 55108-1095, United States of America; firstname.lastname@example.org
Original recibido el 4 de septiembre de 2007;
aceptado el 3 de diciembre de 2007
Abstract. Wheeler, G. A. 2007. Carex sagei (Cyperaceae), the correct name for C. barrosii.
The holotype of Carex sagei comes from central Chile, and this name has long been treated as a synonym of C. fuscula. Recent study indicates, however, that C. sagei is referrable to Carex section Ceratocystis, whereas C. fuscula belongs in section Spirostachyae. It is also demonstrated that C. sagei is the correct name for plants currently called C. barrosii. Carex sagei is known from Argentina, Chile, and the Falkland Islands (Islas Malvinas), where it frequents hydric habitats, such as marshes, wet meadows, and the margins of lakes, from near sea level to about 850 m.
Keywords. Carex; Cyperaceae; Ceratocystis; South America; Taxonomy.
Resumen. Wheeler, G. A. 2007. Carex sagei (Cyperaceae), nombre correcto de C. barrosii.
El holotypo de Carex sagei proviene de Chile central, y su nombre ha sido tratado desde hace tiempo como sinónimo de C. fuscula. Un estudio reciente indicó, sin embargo, que C. sagei is asignable a Carex sección Ceratocystis, mientras que C. fuscula pertenece a la sección Spirostachyae. Se demuestra además que C. sagei es el nombre correcto de plantas actualmente denomindas C. barrosii. Carex sagei crece en Argentina, Chile, e Islas Malvinas (Falkland Islands), donde frecuenta hábitats palustres tales como pantanos, pastizales húmedos y márgenes de lagos, desde casi el nivel del mar hasta los 850 m s.m.
Palabras clave. Carex; Cyperaceae; Ceratocystis; Sudamérica; Taxonomía.
The genus Carex L. (Cyperaceae) is represented in austral South America with about 110 species, most of them growing in the mountains and cooler regions of the continent. The great naturalist Rodulfo A. Philippi (1808-1904), born in Germany and late director of the Chilean Museo Nacional de Historia Natural in Santiago (Taylor & Muñoz-Schick, 1994), described Carex sagei Phil. (Fig. 1) from plants collected by Carlos Sage "en la Araucanía" in central Chile (Muñoz- Pizarro, 1960: 32). Kükenthal (1899, 1909) and subsequent authors (e.g., Léveillé, 1915; Barros, 1947, 1969; Guaglianone, 1996) placed the name under the synonymy of C. fuscula D'Urv., a species invariably assigned to Carex sect. Spirostachyae (Drejer) L. H. Bailey. But recent examination of the holotype of C. sagei reveals that it is neither assignable to C. fuscula nor belongs in sect. Spirostachyae.
Fig. 1. Carex sagei. A, holotype (from C. Sage, s.n.). B, inflorescence (from C. Sage, s.n.). Bars: A, bar = 10 cm; B, bar = 1 mm.
RESULTS AND DISCUSSION
Kükenthal (1899, 1909) included members of sect. Ceratocystis Dumort. (his Extensae Fries) in sect. Spirostachyae, but recent workers (e.g., Jermy et al., 1982; Crins & Ball, 1988; FNA, 2003) have treated these two groups separately. The members of sect. Spirostachyae and sect. Ceratocystis form "two distinct but closely related sections" (Crins & Ball, 1988: 41), with indeed some clear-cut differences existing between them. For instance, reddish brown crystalline inclusions occur in epidermal cells of sect. Spirostachyae but are absent in sect. Ceratocystis. Also, members of sect. Spirostachyae have elliptical achenes and usually cylindrical spikes, whereas members of sect. Ceratocystis have obovate achenes and generally ovoid to subglobose spikes (Crins & Ball, 1988; FNA, 2003). It is also noteworthy that members of sect. Spirostachyae have glycoflavones in their foliage, whereas members of sect. Ceratocystis produce flavonols (Harborne, 1971; Manhart, 1990). The presence of flavonols in members of sect. Ceratocystis, a class of flavonoids otherwise rare in the genus (Harborne, 1971), seems to be, at least in part, responsible for the yellowish-green foliage of these species.
Carex fuscula, in section Spirostachyae, has reddish brown crystalline inclusions, conspicuous even to the unaided eye, in epidermal cells of both reproductive (Fig. 2C) and vegetative (Figs. 3B-C) structures. As shown in Fig. 2, numerous epidermal cells in the perigynia of C. fuscula (Fig. 2C) contain colored cystalline inclusions, whereas such inclusions are absent in perigynia from the type collections of C. sagei (Fig. 2A) and C. barrosii (Fig. 2B). Utilizing reflected (Fig. 3B) and transmitted (Fig. 3C) light, Fig. 3 shows that epidermal cells in the ventral sheaths of C. fuscula once again contain reddish brown cystalline inclusions, whereas such inclusions are absent from the ventral sheaths of C. sagei (Fig. 3A). Also of taxonomic importance, C. fuscula has essentially ribless perigynia (Fig. 2C), short- to long-peduncled cylindrical spikes, elliptical achenes, and short- to long-awned pistillate scales. Contrarily, examination of the holotype of C. sagei reveals that it has: ribbed perigynia (Figs. 2A); subglobose spikes on short peduncles (Fig. 1B), obovate achenes, and non-awned, acute to acuminate scales. Based on the morphological features just mentioned, it is abundantly clear that C. sagei is anomalous in sect. Spirostachyae. On the other hand, the characteristics of C. sagei strongly suggest it belongs in sect. Ceratocystis. Notably, chemical tests were not conducted on the holotype of C. sagei due to a paucity of plant material.
Fig. 2. Carex. A, C. sagei, perigynium (from C. Sage, s.n.). B, C. barrosii, perigynium (from W. J. Eyerdam & A. A. Beetle 24612). C, C. fuscula, perigynium (from A. Ruiz & F. A. Roig 15138). Bars = 1 mm.
Fig. 3. Carex. A, C. sagei, ventral sheath (from C. Sage, s.n.). B, C, C. fuscula. B, portion of ventral sheath, in reflected light (from A. Ruiz & F. A. Roig 15138). C, portion of ventral sheath, in transmitted light (from A. Ruiz & F. A. Roig 15138). Bars = 1 mm.
The type collection of C. barrosii Nelmes [W. J. Eyerdam & A. A. Beetle 24612 (holotype K; isotypes GH, MO, NA)] comes from the west shore of Lago Nahuel Huapi in Río Negro Province, Argentina, and most recent authors (e.g., Barros, 1969; Marticorena & Quezada, 1985; Wheeler, 1988; Guaglianone, 1996) recognize this entity as a good species (see Fig. 2B). It should be noted, however, that some workers (Kükenthal, 1909; Crins & Ball, 1988) consider the South American plants indistinct from C. cataractae R. Br., whose type comes from Tasmania. In the treatment below the South American entity is considered distinct from the Australasian C. cataractae (sect. Ceratocystis).
In general aspect the three diminutive plants comprising the holotype of C. sagei, one of which (Fig. 1B) is stored in a packet not shown in Fig. 1A, superficially resemble C. fuscula var. fuscula (sensu Kükenthal, 1909). Of puissant taxonomic significance, however, the spikes (Fig. 1B), perigynia (compare Figs. 2A and 2B), achenes, pistillate scales, and epidermal cell structure (i.e., the absence of reddish brown crystalline inclusions; see Fig. 3A) of C. sagei are essentially identical to those same diagnostic features in the type collection of C. barrosii. Also in this regard, in an earlier paper (Wheeler, 1988) it was pointed out that some diminutive plants, which represented new reports of C. sagei (as C. barrosii) from Tierra del Fuego and the Falkland Islands (Islas Malvinas), were originally misidentified as C. fuscula.
Based on the morphological evidence presented above, and the ICBN "rule of priority," the correct name for C. barrosii is C. sagei. Henceforth, the name C. sagei should appear in the floras of Argentina, Chile, and the Falkland Islands (Islas Malvinas).
Carex sagei Philippi, Anales Univ. Chile 93:494. 1896. TYPE: Chile, "Araucania," sine data, C. Sage s.n. (holotype SGO-46071!).
Carex barrosii Nelmes, syn. nov., Kew Bull. 1955: 87. 1955. TYPE: Argentina, Prov. Río Negro, west shore of Lago Nahuel Huapi, 850 m, 5-II-1939, W. J. Eyerdam & A. A. Beetle 24612 (holotype, K; isotypes, GH!, MO!, NA!).
Carex flava L. subsp. brevirostrata Kük., syn. nov., Bot. Jahrb. Syst. 27:545. 1899. TYPE: Chile, Concepción, s.d., Neger 22 (syntype B, destroyed). Chile, Río Maoso [sic], s.d., Reiche s.n. (syntype B, destroyed).[The correct spelling is Río Manso].
Carex sagei occurs in Argentina and Chile, where it ranges more or less continuously from about 39°S. Lat. to 52°S. Lat., with disjunct sites also known from Tierra del Fuego and the Falkland Islands (Islas Malvinas); it is unknown, thus far, from Staten Island (Isla de los Estados). See distribution map for C. sagei (as C. barrosii) in Wheeler (1988: 130). Unfortunately, the exact location and date of collection for the holotype of C. sagei are unknown to me.
This species, which characteristically has yellowish- green foliage and yellowish to yellowishbrown perigynia, grows in cespitose clumps and frequents moist to wet sites, such as in marshes and meadows and along the margins of lakes. It grows from near sea level to about 850 m, and plants with mature fruit have been collected from November through March. Carex sagei is the only member of section Ceratocystis in austral South America, although a putative natural hybrid between C. sagei (as C. barrosii) and C. inconspicua Steud. has been reported (Wheeler & Zöllner, 1996:328, Figs. 10 & 11) from Valdivia Province (X Región, Los Lagos) in Chile.
The author wants to thank E. R. Guaglianone (Instituto de Botánica Darwinion, Argentina) for reading an early draft of the manuscript and making sever- al useful suggestions; Raúl Pozner for writing the Spanish resumen; M. Muñoz-Schick (Museo Nacional de Historia Natural, Chile) for the loan of Carex types from SGO; and a special thanks to J. A. Janssens (Lambda-Max Ecological Research) for the excellent photographs. Also the curators and directors of the following herbaria for the loan or in-house study of specimens: AAU, B, BAB, BM, C, CONC, G, GH, GOET, H, K, L, LIL, LP, MIN, MO, NA, P, S, SGO, SI, UC, and UPS.
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