Chusquea nedjaquithii Ruiz-Sanchez, Mejía-Saulés, & L. G. Clark, 2014

Ruiz-Sanchez, Eduardo, Mejía-Saulés, Teresa & Clark, Lynn G., 2014, Chusquea nedjaquithii (Poaceae: Bambusoideae, Bambuseae, Chusqueinae), a new endemic species from Oaxaca, Mexico, Phytotaxa 184 (1), pp. 23-30 : 25-28

Chusquea nedjaquithii Ruiz-Sanchez, Mejía-Saulés, & L. G. Clark sp. nov., Figs. 1–2 .

TYPE:— MEXICO. Oaxaca: Candelaria Loxicha, Portillo del Rayo , Finca El Encanto , 15°58’41”N, 96°31’43”W, 1600 m, 1 June 2013 , E. Ruiz-Sanchez & L. Cervantes 445 (holotype: XAL!; isotypes: IEB!, ISC, MEXU!) .

Chusquea nedjaquithii is similar to C. liebmannii but differs in having culms with deciduous hairs, an oblate central bud, fewer subsidiary branches (13–17) but these larger in diameter, strongly geniculate subsidiary buds and branches in one row in an incomplete verticil, oblique foliage leaf blade bases, and longer (5–10 mm) inner ligules of the foliage leaves.

Rhizomes pachymorph. Culms 4–15 m tall, 1.5–4 cm in basal diameter, arching, sometimes clambering. Internodes 14.5–22 cm long, 22–50 per culm, terete, with hirsute deciduous hairs, strigose and red wine in color when young, becoming glabrous and green when old. Culm leaves 21–23.9 cm long, abaxially slightly scabrid, deciduous, triangular, the margins entire and glabrous on both sides, juncture of the sheath and blade obscure, apparently forming a continuous sheath, apex apiculate; girdle not developed. Nodes at mid culm with ca. 8–11 buds, consisting of one larger oblate central bud subtended by 8–10 smaller, closely adjacent circular buds arranged in a single row, and a patch of 5–7 subsidiary buds in a single row on the opposite side of the culm from the central bud, all the buds arising just above the nodal line, nodal line dipping markedly below the central bud, supranodal ridge present and prominent, lower nodes lacking subsidiary buds but encircled by root thorns. Branching intravaginal, the sheaths becoming deciduous when branches develop, 8–10 branches subtending the central bud and a patch of 5–7 branches on the opposite side of the culm per node, all branches strongly geniculate, growing down and later turning upward, 1–1.5 mm in diameter, 8.5–26 cm long, branch internodes hirsute, the larger main branch half of the diameter of the main culm. Foliage leaves (5)8–11(12) per complement; sheaths glabrous, margins ciliate; leaf blades 6.5–9 cm long, 1.3–2.2 cm wide, L: W = 3.6–5, adaxially and abaxially glabrous, not tessellate, the base oblique, the apex acuminate, the margins serrulate; pseudopetioles 2–3 mm long, adaxially and abaxially glabrous, or abaxially with a tuft of hairs that may extend along of the midrib into the base of the blade; inner ligules 5–10 mm long, acute; outer ligules to 0.5 mm long, ciliate. Synflorescences not seen.

Habitat and distribution:—This species is only known from one population in the Sierra Madre del Sur in the state of Oaxaca. Chusquea nedjaquithii inhabits Neotropical cloud forest in the ecotone with tropical dry forest. This species grows sympatrically with undescribed Chusquea species. In the same locality, Brailovsky (1987) described a new tribe, genus and species of a hemipteran insect, Barreratalpa Brailovsky (1987: 157) . This insect was discovered feeding on cultivated Asiatic bamboos, but is also known to associate with Chusquea , so it likely occurs on C. nedjaquithii .

Comparison:—Morphologically Chusquea nedjaquithii is most similar to C. liebmannii . The differences between C. nedjaquithii and C. liebmannii are the following: main culms with deciduous hairs, becoming strigose, central bud oblate, subsidiary branches 13–17 arranged in a single row in two patches (forming an incomplete verticil) and strongly geniculate, foliage leaf blades oblique at the base and with an inner ligule 5–10 mm long in C. nedjaquithii , vs. culms glabrous, central bud circular, subsidiary branches> 100 in 2 to 3 rows forming a complete verticil and not geniculate, foliage leaf blades attenuate at the base and with an inner ligule 0.5–1 mm long in C. liebmannii .

Etymology:—This species honors Mr. Ned Jaquith (1939–2013), a long-time bamboo grower and nurseryman who gave unstintingly of his knowledge and enthusiasm for bamboo species. We recognize Ned’s extensive contributions to the bamboo community by dedicating this species to his memory.

Phenology:—Flowers of this species have never been collected. However, E. Ruiz-Sanchez observed some dead individuals in the population that could have flowered and died one or two years prior to the type collection.

Additional specimen examined:— MEXICO. Oaxaca: Candelaria Loxicha, Portillo del Rayo , Finca El Encanto , 15°58’41”N, 96°31’43”W, 1600 m, 22 Nov. 2012, L . Cervantes 08 BA ( XAL) .

Figures

FIGURE 1.Chusquea nedjaquithii.A. Mid-culm section,showing branching development,hirsute indumentand foliageleaf complements. B. Nodal region, showing oblate central bud, subsidiary branches and hirsute culm. C. Complete culm leaf. D. Foliage leaf blade, showing inner ligule and serrulate margin. E. Detail of central branch development. Based on E. Ruiz-Sanchez & L. Cervantes 445. Drawn by Edmundo Saavedra.

FIGURE 2. Chusquea nedjaquithii. A. Nodal region, showing oblate central bud, subsidiary branches and intravaginal branch pattern. B. Nodal region, showing subsidiary branches in development. C. Lateral view of the nodal region, showing incompletely verticillate subsidiary branches in development and part of the culm leaf. D. Central branch in development. E. Apical culm region, showing hirsute indument and branches in development. F. Foliage leaf complements. Photos by E. Ruiz-Sanchez.