A new species of Otatea (Poaceae: Bambusoideae: Bambuseae) from Queretaro, Mexico.
Previous phylogenetic studies based on morphological and molecular data support the monophyly of Otatea and its sister relationship with the Mesoamerican bamboo genus Olmeca (Ruiz-Sanchez et al., 2008; Ruiz-Sanchez et al., 2011b). Two morphological synapomorphies have been identified for Otatea: 1) branch complements with three subequal and ascending branches and 2) spikelets with pubescent lemmas (Ruiz-Sanchez et al., 2008). However, two recently described species of Otatea (O. reynosoana and O. transvolcanica) mostly have only one or two branches per node. Sometimes three branches occur with the second and third branches smaller in diameter than the central or primary branch (Ruiz-Sanchez et al., 2011a). Like most bamboos, Otatea is monocarpic with mass flowering in cycles that, according to herbarium records, occur in 8-30 year cycles (Guzman et al., 1984; Judziewicz et al., 1999; Ruiz-Sanchez et al., 2011a); populations usually flower for two or three years consecutively and die (Ruiz-Sanchez et al., 2011a). Due to the long intervals between flowering times, a few species have been described based only on vegetative features, including O. carrilloi and O. transvolcanica (Ruiz-Sanchez et al., 2011a).
A new Otatea species from Sierra Gorda of Queretaro with only one (rarely two) branches per node, erect culm leaf blades, and the absence of oral setae both in culm and foliage leaves is described and illustrated in this paper. Also, a key to the eight species of Otatea is presented.
Key to the species of Otatea
1 Foliage leaves of the primary branches with blades 0.3-1.2 cm wide, abaxially green.... 2
1 Foliage leaves of the primary branches with blades 0.6-6 cm wide, abaxially glaucous.... 4
2 Culm leaf blades erect; foliage oral setae absent.... 7
2 Culm leaf blades reflexed; foliage oral setae present.... 3
3 Foliage leaf blades 18-26 cm long; foliage oral setae 6.6-24.1 mm long, fimbriae 8.4-21.8 mm long, straight; culm leaf oral setae 15-30.6 mm long, fimbriae 10.3-19.3 mm long, straight.... O. carrilloi Ruiz-Sanchez, Sosa & Mejia-Saules
3 Foliage leaf blades 10-16 cm long; foliage oral setae 2.5-6 mm long, fimbriae 1-4 mm long, curly; culm leaf oral setae 2.5-11.5 mm long, fimbriae 1.5-4 mm long, curly.... O. glauca L. G. Clark & G. Cortes
4 Culm leaf blades reflexed.... 5
4 Culm leaf blades erect.... 6
5 Foliage oral setae 4.3-6 mm long, free; lobes of the outer ligule absent; culm leaf sheaths 9.5-12.5 cm long, non-overlapping; culm leaf blades 1.6-7.5 cm long.... O. ximenae Ruiz-Sanchez & L. G. Clark
5 Foliage oral setae 13-21.5 mm long, connate for the basal one-third or more; lobes of the outer ligule present 3-8 mm long; culm leaf sheaths 24-29.5 cm long, overlapping; culm leaf blades 9-20 cm long.... O. transvolcanica Ruiz-Sanchez & L. G. Clark
6 Oral setae of culm and foliage leaves papyraceous, white; branches per node usually one or two; foliage leaf blades abaxially with a patch of white cilia at the base on both sides of the midrib.... O. reynosoana Ruiz-Sanchez & L. G. Clark
6 Oral setae of culm and foliage leaves coriaceous, brown or purple; branches per node three, subequal; foliage leaf blades abaxially with a patch of yellow to brown cilia at the base on one side of the midrib.... O. fimbriata Soderstr.
7 Development of three subequal and ascending branches per node; fimbriae on culm leaves 4-7 mm long; some populations develop oral setae on culm leaves.... O. acuminata (Munro) C. Calderon & Soderstr.
7 Development of one main ascending branch per node, if two branches present then the lateral narrower than the main or central; fimbriae on culm leaves 1-3 mm long; lack oral setae on culm leaves.... O. ramirezii Ruiz-Sanchez
[FIGURE 1 OMITTED]
Otatea ramirezii Ruiz-Sanchez sp. nov. Fig. 1.
Culmi 2 -3 m alti, 0.8-1-7 cm diam, erecti. Folia culmorum 12-17 cm longa; vaginae 10-12 cm longae, laminae 1.8-4.5 cm longae, erectae, triangulares, abaxialiter glabrescentes. Vaginarum caulinarium setae orales desunt. Ramus unus raro duo per nodum. Secundarius et tertiarius nodus unum ramum ferens. Primarius ramus 33-48 cm longus. Folia ramorum 3-7 per complementum, vaginae glabrae; laminae 6.5-12.5 cm longae, 0.4-1.2 cm latae, lineares vel lineari-lanceolatae. ad 30 mm longae, foliorum frondosarum setae orales desunt.
Rhizomes with necks 5-15 cm long. Culms 2-3 m tall, 0.8-1.7 cm in basal diameter, erect; internodes 12-16 cm long, terete, glabrous, green when young and brown-yellow when old, hollow, the walls 3-5 mm thick, the lacuna occupying <50% of the total diameter. Culm leaves 12-17 cm long, non-overlapping, deciduous; sheaths 10-12 cm long, 3.5-5 cm wide at the base, the leaf blades 1.8-4.5 cm long, triangular, abaxially and adaxially glabrous, the margins ciliate when young, glabrous when old; inner ligule a coriaceous rim 0.5-1 mm long, irregular, ciliate; oral setae absent; fimbriae at the apex of the sheath on both sides of the blade, 1-3 mm long, ca. 0.05 mm wide, terete, free, curly; blades 1.8-4.5 cm long, triangular, erect, persistent, shorter than the sheaths, glabrous on both sides, margin glabrous, apex attenuate-subulate. Branching intravaginal; one main branch per node, if two then the central 3-4 times wider than the lateral, sometimes both branches are sub-equal and these are diverging from each other and rebranching, 33-48 cm long, diverging from the main culm at 45-60o, with only one branch in the second and third order of branching; supranodal ridge pronounced; nodal line horizontal. Foliage leaves 3-5(-7) per complement, when young 5-7 per complement; sheaths glabrous, rounded on the back; oral setae absent; fimbriate at shoulders sheath summit, the fimbriae 1-2 mm long, ca. 0.05 mm in diameter, terete, free, curly; outer ligule an irregular glabrous rim up to 0.1 mm long; inner ligule 0.3-0.5 mm long, truncate, ciliate; pseudopetioles ca. 1 mm long, brownish, pulvinate at the base; blades (6.5)8-11(12.5) cm long, 0.4-0.8(1.2) cm wide, linear to linear-lanceolate, green adaxially and glabrous abaxially, with a patch of white cilia at the base extending along one side of the midrib for 2-3 mm, the base attenuate, the apex attenuate-subulate, the margins weakly serrulate. Synflorescences not seen.
TYPE: MEXICO, Queretaro, 500 m antes de llegar a San Juan Tetla desde El Apartadero, municipio de San Joaquin, 20[grados]58'40.8" N, 99[grados]29'47" W, bosque tropical caducifolio, suelos calizos, alt. 1223 m, 10 Jul. 2010, E. Ruiz-Sanchez & A. de Nova 304 (holotype: IBUG; isotypes: IEB, MEXU, XAL).
Habitat and distribution. Apparently, Otatea ramirezii represents a narrow endemic of the southernmost part of the Sierra Gorda in Queretaro, where it forms large populations inhabiting tropical dry forests and their ecotone with oak forests on hillsides composed of calcareous rocks at elevations between 1200 and 1600 m.
On the basis of morphology, Otatea ramirezii morphologically resembles O. acuminata, O. carrilloi and O. glauca. All four are similar in habit with culms that are erect or arching apically and their foliage leaves that are similar in size and form. However, the latter three species develop three subequal ascending branches per node, whereas O. ramirezii develops mostly only one branch per node (Table 1). In some cases, two branches per node are present, but the second one is noticeably narrower than the main branch and it develops later. Additionally, O. ramirezii lacks oral setae in culm and foliage leaves and has erect culm leaf blades. Otatea carrilloi and O. glauca have oral setae in both culm and foliage leaves and their culm leaf blades are reflexed. Alternatively most of the populations in Otatea acuminata have oral setae in the culm leaves but they are absent in the foliage leaves and its culm leaf blades are erect (Table 1). Otatea carrilloi and O. glauca are known from a single population each. Both are endemic to Chiapas. Otatea acuminata has the widest geographical distribution in Mexico, including two populations near O. ramirezii, one in Queretaro only 22 km to northwest of O. ramirezii on the other side of the Sierra Gorda and another one 53 km to the southeast of O. ramirezii in the Barranca of Tolantongo, Hidalgo. The populations of Otatea acuminata in Queretaro and Hidalgo grow in calcareous soils and plants from both of these populations develop three subequal ascending branches per node.
Etymology. The specific epithet honors the memory of Raymundo Ramirez Delgadillo (1968-2011), professor from the Universidad de Guadalajara, Mexico, whom I most owe my interest in systematic botany.
The author is particularly grateful to Arturo de Nova for his invitation to collect Fouqueria species in the locality where the new Otatea species grows. Special thanks are given to Pablo Carrillo Reyes and Heather Driscoll for improving the manuscript with their comments and to Flor Rodriguez Gomez for all her support. I also thank three anonymous reviewers whose suggestions greatly improved the manuscript. The illustration is done by David Jimeno Sevilla. Special memory thanks go to Raymundo Ramirez, a great botanist person.
Recibido en julio de 2011.
Aceptado en enero de 2012.
Guzman, R., M. C. Anaya & M. Santana. 1984. El genero Otatea (Bambusoideae), en Mexico y Centroamerica. Bol. inst. Bot. Univ. Guadalajara 5: 2-20.
Judziewicz, E. J., L. G. Clark, X. Londono & M. J. Stern. 1999. American bamboos. Smithsonian institution Press. Washington D.C., USA. 392 pp.
Londono, X. & L. G. Clark. 1998. Eight new taxa and two new reports of Bambuseae (Poaceae: Bambuseae) from Colombia. Novon 8: 408-428.
Ruiz-Sanchez, E. & V. Sosa. 2010. Delimiting species boundaries within the Neotropical bamboo Otatea (Poaceae: Bambusoideae) using molecular, morphological and ecological data. Molec. Phylog. Evol. 54: 344-356.
Ruiz-Sanchez, E., V. Sosa & M. T. Mejia-Saules. 2008. Phylogenetics of Otatea inferred from morphology and chloroplast DNA sequence data and recircumscription of Guaduinae (Poaceae: Bambusoideae). Syst. Bot. 33: 277-283.
Ruiz-Sanchez, E., V. Sosa, M. T. Mejia-Saules, x. Londono & L. G. Clark. 2011a. A taxonomic revision of Otatea (Poaceae: Bambusoideae: Bambuseae) including four new species. Syst. Bot. 36: 314-336.
Ruiz-Sanchez, E., V. Sosa & M. T. Mejia-Saules. 2011b. Molecular phylogenetics of the Mesoamerican bamboo Olmeca (Poaceae: Bambuseae): implications for taxonomy. Taxon 60: 89-98.
EDUARDO RUIZ-SANCHEZ (1,2)
University of California, Berkeley, Plant and Microbial Biology, 431 Koshland Hall, Berkeley, CA. 94270, USA.
(1) Adscripcion actual: Instituto de Ecologia, A.C., Centro regional de Bajio, red de Biodiversidad y Sistematica, Av. Lazaro Cardenas 253, 61600, Patzcuaro, Michoacan, Mexico.
(2) Autor para la correspondencia: email@example.com
Table 1. Comparisons of morphological characters among Otatea acuminata, O. glauca, O. carrilloi and O. ramirezii. Character/taxa O. acuminata O. glauca Culm habit erect and arching arching apically apically Culm size length (m) 2-10 8 diameter (cm) 1-5 3 Internode size length (cm) 9.5-24 27-30 wall thickness 2-4 1.5-2 (mm) Culm leaves sheath length (cm) 5-30 14-22 relative position overlapping non- or not overlapping duration deciduous or deciduous persistent Culm leaf blades length (cm) 6-18 3.5-8.2 position erect reflexed basal margin ciliate, glabrous glabrous indument or hirsute Oral setae on culm leaves length (mm) 10-15 when 2.5-11.5 present color in living brown bright green specimens Fimbriae on culm present present leaves position at shoulders at shoulders posture curly curly length (mm) 4-7 1.5-4 Branches per node 3 3 Foliage leaf blade length (cm) 4-22 10-16 width (cm) 0.3-1.2 0.3-1 Oral setae on foliage absent present leaves length (mm) -- 2.5-6 connate at base -- no color when live -- green Fimbriae on foliage leaves length (mm) 1-3 1-4 posture curly curly Character/taxa O. carrilloi O. ramirezii Culm habit arching apically erect Culm size length (m) 3-5 2-3 diameter (cm) 1-3.5 0.8-1.7 Internode size length (cm) 11-19 12-16 wall thickness 3.5-6.9 3-5 (mm) Culm leaves sheath length (cm) 19-28 10-12 relative position overlapping non- overlapping duration deciduous deciduous Culm leaf blades length (cm) 10-31 1.8-4.5 position reflexed erect basal margin fimbriate glabrous indument Oral setae on culm leaves length (mm) 15-30.6 absent color in living green-yellow -- specimens Fimbriae on culm present present leaves position at blade at shoulders baseand sheath summit posture straight curly length (mm) 10.3-19.3 1-3 Branches per node 3 1 (rarely 2) Foliage leaf blade length (cm) 18-26 6.5-12.5 width (cm) 0.6-0.9 0.4-1.2 Oral setae on foliage present absent leaves length (mm) 6.6-24 -- connate at base no -- color when live green-yellow -- Fimbriae on foliage leaves length (mm) 8.5-22 1-2 posture straight curly
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|Title Annotation:||texto en ingles|
|Publication:||Acta Botanica Mexicana|
|Date:||Apr 1, 2012|
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