Agave garciae-mendozae, a new species from central Mexico*

Raquel Galván Villanueva** and Luis Hernández-Sandoval

Summary: Agave garciae-mendozae R. Galván V. et L. G. Hernández S. sp. nov. is native to the Mexican states of Hidalgo, Querétaro and San Luis Potosí. Its vegetative and reproduc­tive characters place it in group Marginatae. The species is found on mountain slopes and rocky outcrops with different vegetation types.

Introduction

Floristic-taxonomic studies of the genus Agave carried out in Hidalgo, Querétaro, San Luis Potosí and adjacent zones have resulted in the discovery of a new species belonging to subgenus Littaea, group Margi­natae. The Marginatae include 21 species and a total of 27 taxa distributed from New Mexico and Texas to Mexico and Guatemala (Gentry, 1982). The species is distributed in the Río Moctezuma basin in Hidalgo, Querétaro and San Luis Potosí, on limestone soils of rocky slopes, often in canyon bottoms with xerophyll scrub and in a zone intermediate between the oak and pine-oak zones, at alti­tudes from 1800 to 2350 m. It flowers from June to August, with fruits ripening by September.

Figure 1. Agave garciae-mendozae Galván & Hernández. A. Flowering plant. B. Leaf, with variable margins. C. Flower. D. Open capsule. E. Closed capsule. F. Apical view of fruit. G. Seed. Drawing by M. Domínguez.

Agave garciae-mendozae R. Galván V. et L G. Hernández S. sp. nov. (Fig. 1)

Planta rosulacea, rosula aperta, foliis atroviridibus aliquantum glaucis, lanceolatis, dimidio superiore flexibilibus, applanatis vel leviter concavis. Inflorescentia 3.2-5.5 m alta, spica in pedunculi dimidio superiore vel 2/3 partibus superioribus. Flores 2.8-3.9 cm longi, tubo1.5-2.5 mm longo. Capsula oblonga vel oblongo-elipsoidea, 1.5-2 cm longae.

Perennial plant, single or somewhat cespitose, rosettes openly spreading, 75-115(-130) cm high, 100-175 cm diameter, subcaulescent; with (30-)50-80 mature leaves, (33-)48-78 cm long, 6-13 cm wide, lanceolate, fleshy, thin, flexible mainly in superior half, dark green to glaucous green, flat to somewhat concave above, flat or slightly convex below, straight or incurved, margin horny, 0.5-2 mm wide, continuous, gray to dark reddish brown, easily separated, teeth variable, straight to curved, 7-14 mm long, deltoid, flattened, gray with reddish brown tip, narrowly acuminate, (0.7-)1-4 cm apart, often with secondary teeth; terminal spine conic to subulate, 2.7-4.8 cm long, gray, sometimes somewhat reflexed, widely grooved on upper surface, keeled under­neath, decurrent on the leaf; inflorescence 3.2-5.5 m high, spike 1/2 to 2/3 longer than the peduncle; peduncle reddish to glaucous green, bracts 7.5-23 cm long, 1-3.5 cm wide at base, long-deltoid, chartaceous to papery, ter­minal spine rigid, floral bracts 2.3-2.6 cm long, 2 cm wide at base, ovate, reddish, acuminate; flowers 2.8-3.9 cm long, geminate, light green to yellowish green and somewhat glaucous; pedicels 2-3 mm long; ovary 8-12 mm long, 3.5 mm wide, cylindric, neck constricted, 2-3 mm long, 1.2-1.8 mm wide, tube 1.5-2.5 mm long, 5-6 (-7) mm wide, tepals 12.5-16 mm long, 4-5 mm wide, oblong, involute, sometimes reddish, acute, lightly cucullate and hairy, inner series with a wide keel; filaments 3.8-4.5 cm long, inserted in the base of the tepal, anther 10-13 mm long, yellow or greenish yellow; capsules (1.5-) 1.7-2 cm long, 9-11 mm wide, oblong or oblong-ellipsoid, shortly apiculate; seeds 3-4.9 mm long, 2-2.7 mm wide, semicircular, black, marginal wing 0.8-1 mm wide, hilar notch shallow.

Type: MEXICO, HIDALGO. Mpio. Zimapán, Cañada la Corona, 4 km N of El Tathi, Flourensia resinosa scrub, 2040 m, 5.VIII.1996, R. Galván y S. Galván 4646 (holotype, ENCB; isotypes, CHAPA, MEXU, MO, QMEX, UAMIZ).

Paratypes: HIDALGO: Mpio. Metztitlán, 5 km NW of Santa Mónica Autempan, 17.VIII.2001, R. Galván, A. García & S. Franco 5195, 5796, 5797 (CHAPA, ENCB, MEXU, QMEX); Mpio. Zimapán, Cerro Dashxi, 2 km S of Zimapán, 25.1.1996; R. Galván & S. Galván 4571, 4572 (ENCB, CHAPA, MEXU, GH, UAMIZ); Peña Blanca, 15 km ENE of Zimapán, 19. IV. 1997, R. Galván & S. Galván 4753 (ENCB, CHAPA, MEXU); Ibid., 30. VIII. 1998, R. Galván & S. Galván 4937 (ENCB, MEXU). QUERÉTARO: Mpio. Pinal de Amoles, 12 km NW of Bucareli, 1. VIII. 2001, L. Hernández 4693 (QMEX). SAN LUIS POTOSÍ: Mpio. Alvarez, 20 km E of San Luis Potosí, along highway to Rio Verde, 16. VI. 1994 (flowering in Botanical Garden of UNAM, 22.VII.2001), A. García-Mendoza 7079 (MEXU, ENCB).

Figure 2. A. garciae-mendozae in oak-forest at Peña Blanca, Hidalgo. Photo by Raquel Galván

Table 1. Differentiating characters

In the state of Hidalgo this plant was named "arcia" and "shilimaya". At one time a fine, long-lasting fiber, obtained from its leaves, was used for lassos, ropes and brushes. Now this activity is rarely observed and the fiber is used only by fam­ilies for their own use.

A common phenomenon was observed in the populations of Agave garciae-mendozae: many leaves show damage caused by goats that rub their horns against the abaxial surface. Their motive for doing this is unknown, but perhaps it is one way the animals mark their territory.

The Marginatae are characterized by their gen­erally rigid leaves with horny margins and small or large teeth. The inflorescence is a spicate pan­icle, the small flowers are in groups of two or three, the tube is short and widely funnelform, the tepals are longer than the tube, the filaments are at or near the segment base, and the capsules are oblong.

Agave garciae-mendozae shows affinities with A. horrida Lem. and A. kerchovei Lem. From the former it is distinguished by its open rosettes, the color and greater size of its leaves, the grooved terminal spine, a shorter ovary, a more shallow perianth tube and its flexible leaves. From the second it is separated by its shorter rosettes, fewer leaves, shorter ovary, shallower perianth tube, and the color and flexibility of its leaves (Table 1). The species was cited by Magallán (1998) as Agave sp. 1.

This species is named in honor of Dr. Abisaí García Mendoza in recognition of his contributions to the phytogeography and taxonomy of the Mexican Agavaceae.

Acknowledgements

We are grateful to the herbarium curators of ENCB, MEXU and QMEX for permission to con­sult those collections. To Dr. Jorge Meyrán and Fernando Chiang Cabrera for their corrections and suggestions and to the latter for the Latin diagnosis. Special acknowledgements to Antonio Martínez and Julio Rojo for ethnobotanical data and their fellowship in the field.

References

Gentry, H. S. 1982. Agaves of continental North America. University Arizona Press, Tucson, Arizona. 670 p.

Magallán, H. F. 1998. Agavaceae from Querétaro. Licenciate Thesis. Univ. Aut. of Querétaro, Mexico. 155 p.

Raquel Galván Villanueva

Laboratorio de Botánica Fanerogámica

Escuela Nacional de Ciencias Biológicas

Instituto Politécnico Nacional

A. P. 17-564 11410 México, D.F.

(ragalvi31@ hotmail.com)

Luis Hernández-Sandoval

Escuela de Biología

Universidad Autónoma de Querétaro

Cerro de las Campanas, s/n, Querétaro 76017 Qro., México

(luishs@sunserver.uaq.mx)

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*) Work supported by DGPI, Instituto Politécnico Nacional (932698; 32.01).

**) COFAA fellowship, I.P.N.

© Cactus & Succulent Journal of America, 2002