Salvia robertoana Mart.Gord. & Fragoso, 2016

Martínez-Gordillo, Martha, Fragoso-Martínez, Itzi & Salas-Morales, Silvia H., 2016, Salvia robertoana (Lamiaceae), a new species from Oaxaca, Mexico, Phytotaxa 269 (4), pp. 271-278 : 272

Salvia robertoana Mart.Gord. & Fragoso , sp. nov. ( Figs. 1, 2).

Salvia pennellii affinis sed foliis ellipticis vel elliptico-oblongis, laminis 8.1–12 cm longis, 3–3.75 cm latis, tomentulosis supra, albidotomentosis subtus, breviter decurrentibus base, inflorescentiis longioribus, plerumque corollae tubo et labio infero brevioribus differt.

Type:— MEXICO. Oaxaca: Putla, Santa Cruz Itundujia: El Mirador, 9.54 km en línea recta de Santa Cruz Itundujia, 2849 m, 16º48’10”N, 97º36’33”W, 1 August 2008, K. Velasco 3061 (holotype MEXU!).

Herbs unbranched, 0.3–0.9 m tall, stems tan brown colored, densely pubescent with short, multicellular trichomes. Leaf blades elliptic to oblong-elliptic, 8.1–12 × 3–3.75 cm, base decurrent, margin serrulate, involute, apex acute to short-acuminate, upper surface green, bullate, tomentulose, with short sparse trichomes, lower surface pale, tomentose, densely covered with multicellular trichomes, lower side involute; petioles 0.6–3.6 cm long, pubescent. Inflorescences terminal, (8–) 18–30 cm long; peduncle 2–5.6 cm long, internodes up to 2.3 cm long, 6 or more flowers per node; bracts persistent at anthesis, 0.8–1.7 cm long, ovate-caudate, margin cuneate, apex caudate to shortly-acuminate, upper surface glabrescent, lower surface densely tomentose, whitish, with parallel venation. Calyx 9–11 mm long, upper lip 3-veined, densely pubescent, with simple trichomes and spherical glands on the outer surface, mainly along the veins, pubescent inner surface, with antrorse trichomes. Corolla purple, 16–18 mm long, tube 10–12 mm long, ventricose, sometimes slightly curved, papillae absent; upper lip 6–7 mm long, lower lip (4–) 6–8 mm long. Stamens inserted near the mouth of the corolla, filaments 2.7–3.5 mm, connective straight, 4.5–5.2 mm, abaxially with a retrorse tooth. Style pubescent, 1.4–1.6 cm long; gland of the gynobase larger than the mericarps. Mericarps oblong, 1.5–2.1 mm, brown, smooth.

Distribution, habitat and phenology:—The new species is thus far known from the state of Oaxaca, in the region of the Mixteca Alta ( Fig. 3), in Pine-Oak forest and xeric shrublands. It has been collected at 2540–2849 m elevation. Flowering and fruiting in August.

Etymology:—The specific epithet robertoana honors Roberto Carreño-Colorado, an enthusiast in botany who has spent time and resources supporting research on the Mexican Lamiaceae .

Discussion:— Salvia robertoana is a small herb, unbranched, with showy inflorescences, due to size and bluish tones of the calyx and bracts. These features, in addition to the size of the corolla, the lower lip slightly longer than the upper lip, and the presence of a functional lever mechanism, suggest that the new species fits into a melittophilous pollination syndrome ( Wester & Claben-Bockhoff 2011). In Table 1, Salvia robertoana is compared with S. pennellii , which due to its morphological similarity is considered its most closely related species. Although they share traits such as the habit and duration (perennial herbs), as well as the presence of lately deciduous bracts, violet corollas with stamens inserted in the galea and an epapillate corolla tube, S. robertoana can be distinguished by its larger, elliptic to elliptic-oblong leaves, which are tomentose and whitish on the lower side and tomentulose on the upper side, with a shortly decurrent base, longer inflorescences, and usually shorter corolla tube. Salvia pennellii is distributed in northern Mexico ( Fig. 3), where it has been collected in the mountainous zones of San Luis Potosí and Tamaulipas, at 1600 to 2870 m elevation, in oak forests, conifer forests and xeric shrublands, growing on dry and cold limestone slopes (José García, comm. pers.). This species is cultivated as ornamental for the beauty of its flowers and its resistance to low humidity levels (José García, comm. pers.). On the other hand, S. robertoana is endemic to the Mixteca Alta region of the state of Oaxaca, at elevations of 2540 m or higher, where pine and mixed forests predominate.