Chusquea cortesii L. G. Clark & Ruiz-Sanchez, 2013

Ruiz-Sanchez, Eduardo & Clark, Lynn G., 2013, Two new species of Chusquea (Poaceae: Bambusoideae: Bambuseae) from Mexico, one of them morphologically unusual, and a key to the Mexican sections of Chusquea, Phytotaxa 92 (1), pp. 1-12 : 7-10

Chusquea cortesii L. G. Clark & Ruiz-Sanchez , spec. nov., Fig. 3 A–I

TYPE:— MÉXICO. Jalisco: 2.7–3 km al NNW del Zarzamoro, arroyo las Joyas , 600 a 700 m al SSW de Las Joyas, 19°36’45”N, 104°16’34”W, 1700–1750 m, 28 November 1996 , R. Cuevas , L. Guzmán & E. Sánchez 5103 (Holotype: IEB!).

Chusquea cortesii differs from congeneric species in having wide foliar leaf blades, fewer branches per node, longer panicles, shorter spikelets and shorter lemmas.

Rhizomes pachymorph. Culms 2–5 m tall, 0.5–1 cm in basal diameter, scandent to clambering. Internodes 12.6–28.5 cm long, 10–30 per culm, terete, glabrous, green with purple spots or purple, solid become fistulose with age in some. Culm leaves 6.8–13 cm long, glabrous, green when young, becoming straw-colored when old, persistent and some of them deciduous; sheaths 5.5–11.5 cm long, rectangular with rounded shoulders, 4–10 times as long as the blade, the margins entire on both sides; blades 1–1.3 cm long, narrow triangular, erect and deciduous, apex acuminate, margins entire, glabrous; girdle asymmetrically developed, prominent only near the bud complement, 3–6 mm wide, developing a patella, inner ligule 1–3 mm long, glabrous. Nodes at mid culm with ca. 5–10 buds, composed of one larger triangular central bud subtended by 4–9 smaller triangular, closely adjacent subsidiary buds arranged in a single line, the base of the buds arising above the nodal line, lower nodes developing roots that encircle the node; nodal line dipping markedly below the bud, supranodal ridge present and prominent. Branching infravaginal, and extravaginal branching seen in some specimens, the sheaths deciduous, 5–10 branches per node, diverging from the main culm at 45–90 o, 7–33 cm long, 1–1.5 mm in diameter, the larger main branch 1.5–4 mm in diameter, up to 50 cm long, always rebranching. Foliage leaves 3–5 per complement; sheaths glabrous or scabrous, the summit ciliate or glabrous; leaf blades 7–17.5 cm long, 1.1–1.8 cm wide, abaxially pubescent, green-glaucous and adaxially glabrous, green, not tessellate, the base rounded-attenuate, the apex subulate to mucronate, the margin finely serrulate or entire; pseudopetioles 2–3 mm long, adaxially glabrous, abaxially pubescent, inner ligule 1–5 mm long truncate; outer ligule on one side to 0.5 mm long, on the other side a rim ca. 0.1 mm long, ciliate or glabrous. Synflorescences 7–13 cm long, paniculate, narrow, congested, exserted from the subtending sheath, rachis short pubescent; branches 0.5–2 cm long, appressed, angular, pubescent; pedicels 0.5–3.5 mm long, angular, pubescent. Spikelets 5.5–6.5 mm long, laterally compressed, short pubescent. Glumes I and II ovate, margin entire, pubescent; glume I 0.4–0.7 mm long; glume II 0.7–11 mm long, apex rounded ciliate or mucronate. Glumes III and IV pubescent, awned, hyaline, margin short ciliate; glume III including the awn 3.3–3.5 mm long, 1–3-nerved, the awn 1.1–1.5 mm; glume IV including the awn 3.8–4 mm long, 1–3-nerved, the awn 1.5–1.9 mm. Lemmas 5–6 mm long, 5–nerved, green or purple, pubescent, mucronate. Paleas 5–6 mm long, 2–nerved, purple, pubescent, bimucronate. Lodicules 3, membranaceous but slightly thickened at the base, hyaline, long setose, the anterior pair 1.5–2 mm long, the posterior one 1–1.3 mm long. Ovary glabrous; style one, soon bifid, 1–1.3 mm long. Stamens and stigmas not seen. Fruit a basic caryopsis, 2.5–3 mm long, immature.

Habitat and distribution:— Chusquea cortesii grows in pine, pine-oak and cloud forests in Guatemala, Chiapas, Estado de México, Guerrero, Jalisco, Nayarit and Michoacán at (1430–)1700–2743(–3000) m elevation.

Comparison:—Morphologically Chusquea cortesii is most similar to C. nelsonii and C. aperta . The specimens of C. cortesii in herbaria were under C. nelsonii or C. aff. nelsonii , however the morphological differences of these two species are consistent ( Table 3). Chusquea aperta has culm leaf sheaths with overlapping margins above the base, the foliage leaf blades are yellowish-green, abaxially glabrous and tessellate, the synflorescence is an open panicle, and glumes III and IV are glabrous and apiculate to subulate. The geographical distribution of C. aperta is pine-oak and cloud forests in the Gulf of Mexico slopes. Meanwhile C. cortesii and C. nelsonii have culm leaf sheaths with margins free, foliage leaf leaf blades are green-glaucous, abaxially pubescent and not tessellate, the synflorescence is a narrow congested panicle, and glumes III and IV are awned and pubescent. The geographical distributions of C. cortesii and C. nelsonii are in pine, pine-oak and cloud forests in the Pacific slopes. The differences between C. cortesii and C. nelsonii are the following: C. cortesii has foliar leaf blades wider than C. nelsonii (1.1–1.8 vs 0.5–1 cm), fewer branches per node (5–9 vs 15–30), longer panicles (7–13 vs 4–6.5 cm), shorter spikelets (5.5–6.5 mm vs 6.6–7.8 mm) and shorter lemmas (5–6 vs 6.4–7.1 mm).

Etymology:—The specific epithet honors Gilberto Cortés Rodríguez, a Mexican bamboo taxonomist and professor at the Instituto Tecnológico de Chetumal who has made enormous contributions to our knowledge of Mexican bamboos, describing new species, collecting and cultivating Mexican bamboos in the botanical garden Francisco Javier Clavijero at INECOL in Xalapa, Veracruz, México.

Phenology:— We found three specimens in flower, collected in December 1989, 1995 and November 1996 in the state of Jalisco .

Common names:—Otate, tarrito (Spanish).

Additional specimens examined:— GUATEMALA. Quetzaltenango: along old road between Finca Pirineos and Patzulín , dense damp forest, 1200–1400 m, 9 February 1941, P . Standley 87155 ( US). San Marcos: growing wild in lower story of a cloud forest on Volcan Tajumulco, 2438–2743 m, 6 February 1948, F . McClure 21579 ( ISC, US). Suchitepequez : known locally as “tarrito”, 30 January 1948, F . McClure 21574 ( US). MEXICO. Chiapas: Motozintla de Mendoza , Cerro Mozotal, side road from the road up to the microwave tower, 2450 m, 15 o 24’N, 92 o 20’W, 4 February 1989, L . Clark, P . Tenorio & G . Bol 476 ( ISC, MEXU, WIS); 27 km al NO de Motozintla, camino a Coadesmech (torre de microondas), 3030 m, 21 October 1985, J. L . Villaseñor 183 ( MEXU). Guerrero: Atoyac de Álvarez, carr. Atoyac-Puerto Gallo 2km de la desviación a El Iris, 2337 m, 17 o 29’27.3’’N, 100 o 21’4’’W, 7 July 2010, T . Mejía-Saulés, J . Pale & A . Vázquez 2087, 2088 (both XAL). Jalisco: Autlán, north-facing slope of the Sierra de Manantlán Occidental, deep valley of Arroyo de Chilacayote, below Cerro la Piedra Bola , ca. 2.5 km NE of Las Joyas, 9 km SE of Ahuacapán (14 km SSW of El Chante, ca. 20 km SSE of Autlán), 1750–1800 m, 19°37’N, 104°16’30”W, 2 January 1984, H. H . Iltis & R . Guzman M . 29093 ( IBUG, ISC, MEXU, WIS); senderos desde Arroyo El Chilacayote (tributario del Arroyo Las Joyas ) al cerrito central de “Cerro la Piedra Bola” de los mapas, 2–3.5 cm distancia aérea al NE de la Estación Biológica “ Las Joyas ” (“ Zarzamora ”), ca. 9–11 km distancia aérea al SE de Ahuacapán, 1820–1850 m, 19°36’30”N, 104°16’W, 23 December 1984, E. J . Judziewicz, T. S . Cochrane, R . Cuevas & L . Román 4896 ( IBUG, ISC, WIS); Límite norte de la estación científica La Joyas, 1700 m, 10 December 1995, R . Cuevas, J . Aragón & H . Hernández 4979 ( IEB) and 4980 ( WIS); 17–18 km al SE de Autlán , 4–5 km al N de El Zarzamoro, 1600 m, 19°37’54”N, 104°16’14”W, 5 May 1990, L . Guzmán & L . Hernández 1006 ( IEB); arroyo San Campus, 1–2.5 km al SW de Rincón de Manantlán entre el puente rústico y el cañón 1560–1620 m, 19°35’30”N, 104°13’30”W, 4 January 1985, E. J . Judziewicz & R . Guzmán 5070 ( IBUG, WIS); west slope of cerro San Miguel to just below saddle (“ La Ventana ”), 2–7 km ENE of El Durazno (ca. 20 km S of El Chante ) on trail to “La Ventana”, 1100–2460 m, 19°32’N, 104°13’– 104°16’30”W, 22 September 1978, H . Iltis, R . Guzmán, J . Doebley & A . Lasseigne 486 ( IBUG, WIS); E-facing slopes of cerro San Miguel justo below ( N of) saddle at La Ventana, 2000–2350, 19°31’45”N, 104°13’W, 22 September 1978, H . Iltis, R . Guzmán, J . Doebley & A . Lasseigne 28 ( IBUG); Cuautitlán , 5 km al E de Las Joyas, Sierra de Manantlán, 1700 m, 4 February 1983, F. J . Santana 1229 ( IBUG, ISC); La Ventana, 3–4 km NNW de San Miguel ( Sierra de Manantlán ), 1900 m, 1 October 1988, F. J . Santana 4178 ( ISC); Cuautitlán, 15–17 km al NE de Cuautitlán , 3–4 km NNW de San Miguel La Ventana, 1950 m, 19°31’43”N, 104°13’45”W, 27 September 1988, F. J . Santana & J . Benz 4178 ( WIS); Cuautitlán, 13–14 km al NE de Cuautitlán , 2–3 km al NE de El Durazno, 1000–1100 m, 19°32’10”N, 104°15’23”W, 24 March 1988, F. J . Santana & R . Guzman 3387 ( WIS); Upper stretches of road down to El Durazno from La Cumbre jct., 5–6 km (air) NE of El Durazno; 15.5 km (air) SSE of Ahuacapán , upper SW-facing slope of Sierra de Manantlán (occidental), 1940–1980 m, 19°33’14”N, 104°14’31”W, 19 March 1989, M. A . Wetter, T. S . Cochrane & F. J . Santana 2010 ( IBUG, ISC, WIS); Las Juntas, cerca de 2 km al SSW de Las Joyas, en La Sierra de Manantlán , 3 February 1983, R . Guzmán 6119 ( MEXU); Sierra de Manantlán vereda a Las Ventanas, 1000 m, 19°33’N, 104°13’W, 6 March 1982, G . Cortés & F . Ramírez 80 ( XAL); Sierra de Manantlan , road down S slope to Durazno, 1981 m, 30 January 1970, F . Boutin & M . Kimnach 3008 ( MEXU); 16–17 km al NE de Cuautitlán , 1–2 km al SW de La Cumbre, 1850–1050, 29 April 1988, R . Cuevas & L . Guzmán 2861 ( IBUG, WIS); Cerro de los Naranjitos, cerca del arroyo Tecopaiztle , 5 km al SSE del Zarzamoro , Sierra de Manantlán , municipio de Cuauhtitlán, bosque de pino y encino en barrancas de suelos someros, 20 October 1983, R . Guzmán 6329c ( WIS); Cerro el Pinacate, al N de San Miguel , 1750 m, 11 August 1986, R . Ramírez & I . Alcocer 455 ( IBUG, WIS); Mascota, carretera Mascota a Puerto Vallarta km 29.7, a 8.3 km de La Estancia rumbo a Mascota , 1506 m, 20°42’38.6”N, 104°53’5.8”W, 1 January 2006, E . Ruiz-Sanchez & F . Rodríguez 129 ( XAL); Mazamitla, 8 km al E del Puerto el Zapatero, brecha al Montoso, 1950 m, 5 December 1989, J . Villa & J . Chávez 370 ( IBUG); Talpa de Allende, faldas del cerro San Luis, ejido El Cuale, 1750 m, 26 February 1991, 20°25’0”N, 105°2’50”W, G . Castillo, P . Zamora & R . Acevedo 10426 ( MEXU, XAL) . México: San Simón de Guerrero, 1 km antes de San Simón de Guerrero, 2350 m, 7 February 1984, A . Manrique & A . Beetle 692 ( MEXU); Temascaltepec , 4.5 km al E de Temascaltepec por la carretera a México, D. F ., 2 October 1982, R . Guzmán 6046 ( MEXU); A 4.5 K de Temascaltepec a Toluca, pasando el puente Río Verde , 1840 m, 193 o ’1.3’’ N , 100 o 1’45.5’’W, 4 September 2007, E . Ruiz-Sanchez, E . Gándara & D. Ángulo 180 ( XAL). Michoacán: Ciudad Hidalgo, aproximadamente 9 km de Laguna Larga en los Azufres camino a Ciudad Hidalgo, 2359 m, 19°45’1.2”N, 100°40’43.3”W, 9 June 2012, E . Ruiz-Sanchez & J . Álvarez 406 ( IEB); Santa Clara del Cobre, 1 km al S de Copandaro, a la orilla del Lago de Zirahuén , 2000 m, 2 March 1986, J . Rzedowski 39573 ( IEB). Nayarit: Tepic, 12.5 km al SW de El Izote, brecha al Cuatreño , 1430 m, 21 o 29’ N, 104 o 58’ W, 5 December 1989, P . Tenorio, G . Flores & A . Cadenas 16955 ( MEXU) .

Figures

FIGURE 3. Chusquea cortesii. A. Branch complement showing infravaginal branching and abaxially glabrous culm leaf sheath. B. Bud complement showing lateral root appendages. C. Foliar leaf complement. D. Foliage leaf ligular area, abaxial view. E. Synflorescence. F. Detail of the synflorescence showing spikelets. G. Spikelet lateral view showing glumes I, III and lemma. H. Spikelet lateral view showing glumes II, IV and palea. (A-D based on Ruiz-Sanchez & Álvarez 406; E-H based on Cuevas et al. 5103). Drawn by Alfonso Barbosa.