Nahuatlea V. A.Funk

Funk, Vicki A., Sancho, Gisela & Roque, Nadia, 2017, Nahuatlea: a new genus of compositae (Gochnatieae) from North America, PhytoKeys 91, pp. 105-124 : 109-110

Nahuatlea V. A.Funk

Description.

Shrubs or trees, monoecious. Leaves sessile or with a short petiole of no more than 5 mm long, alternate, chartaceous or coriaceous, entire, margins revolute, usually discolorous (silvery or cinereous-tomentose beneath), clustered near the ends of the branches especially late in the flowering cycle. Heads arranged in clusters, rarely solitary, most branches with an apical cluster; sessile or short-pedunculate, peduncles commonly densely scaly-bracted resembling the lowermost involucral bracts, homogamous (flowers bisexual), discoid; involucre obconic (turbinate) or campanulate, shorter than the flowers; phyllaries imbricate, 4-10 seriate, graduate, coriaceous or subcoriaceous. Flowers with corollas homomorphic, white or yellow, actinomorphic, deeply 5-lobed, lobes equal or shorter than the tube, revolute; anthers calcarate, caudate, anther apical appendages apiculate, tails 1-3 mm long, entire or fimbrillate; styles rounded at apex, glabrous, style branches concave. Achenes 5-ribbed sericeous, cuneate-cylindrical, carpopodium conspicuous. Pappus of scabrid bristles, uni- or biseriate, graduated (varying in length) and equally wide throughout or rarely flattened at the tips, ca 1 cm long. [7 species]

Remarks.

Nahuatlea , with some exceptions, is characterized by a combination of characters: short leafy branchlets, entire and revolute blade margins, clusters of sessile or short-pedunculate heads at or near the tips of branches; densely scaly-bracted peduncles (when present); and a pappus that is biseriate, graduated, and equally wide throughout. Most of the exceptions are found in the recently described Gochnatia hiriartiana (Medrano, Villasenor & Medina, 2004) which has solitary heads, and a uniseriate pappus with bristles that are flattened at the tips. However, recently produced sequence data including those of G. hiriartiana support Nahuatlea as monophyletic (Funk, unpublished).

Etymology.

The genus name was selected to honor the indigenous people of eastern central Mexico by naming it after their language. The name is derived from Nahuatl , a language of the Nahuan branch of the Uto-Aztecan language family (known informally as Aztec). It is spoken by an estimated 1.5 million people, most of whom live in Central Mexico. Nahuatl has been spoken in Central Mexico since at least the 7th century AD and it was the language of the Aztecs who dominated what is now central Mexico during the Late Postclassic period of Mesoamerican history. Today the Nahuatl language is spoken in the Mexican states of Durango, Guerrero, Hidalgo, Mexico, Michoacan, Morelos, Oaxaca, Puebla, Tlaxcala, and Veracruz. The distribution of the new genus, Nahuatlea , in central Mexico has substantial overlap with the area so it is appropriate to use it for the name of the new genus (http://en.wikipedia.org/wiki/Nahuatl).

Key to species of Nahuatlea