Solanum lignescens, Fernald,

Stern, Stephen, Bohs, Lynn, Giacomin, Leandro, Stehmann, João & Knapp, Sandra, 2013, A Revision of Solanum Section Gonatotrichum, Systematic Botany 38 (2), pp. 470-496 : 486-488

5. SOLANUM LIGNESCENS Fernald,

Proc. Amer. Acad. Arts 33: 91. 1897.

—TYPE: MEXICO. Guerrero: Acapulco , Nov 1894 (fl, fr), E. Palmer 216 (lectotype, here designated, US-259574 !; isolectotypes: F-66593!, GH-GH00077503!, MO-3378770!, K!, NY-NY00139001!).

Solanum roei Ugent & Iltis, Phytologia 40: 379. 1978.

—TYPE: MEXICO. Chiapas: 6 km NW of Las Rosas, in region of tropical deciduous vegetation on NE slope of Valley of Chiapas, ca. 900 m, 8 Aug 1965 (fl, fr), K. Roe et al. 1045 (holotype: WIS).

Herb or subshrub from a lignescent base, 0.5–1 m tall. Young stems densely pubescent with pale yellow-grey, porrect-stellate hairs, the stalks nearly absent to 0.5 mm, uniseriate, 5–6 rays, 0.2–0.5 mm in length, unicellular, midpoints lacking to 0.2 mm long; older stems glabrescent with yellow-gray bark. Sympodia 3–plurifoliate. Leaf blades 2–7 + 1.5 –4 cm, ovate, chartaceous to membranaceous, sparsely and uniformly pubescent adaxially with stalked stellate trichomes 0.5–1 mm, the rays often absent and the trichomes appearing simple, the base of each trichome somewhat swollen, densely pubescent abaxially with a mixture of stalked and sessile stellate trichomes 1–1.5 mm long, with 2–5 rays and midpoints small or lacking, the trichomes yellowish and almost obscuring the leaf undersides; base truncate to broadly cuneate; apex acute to more or less rounded; petioles 0.2–1 cm, densely stellate-pubescent like the leaf undersides. Inflorescences opposite the leaves or extra-axillary, with (1–) 3–6 (11) flowers, the axes densely stellate pubescent with a mixture of stalked and sessile trichomes ca. 0.5 mm, like those of the stems; peduncles 0.3 –0.8 cm; rachis nearly absent; pedicels 7–12 mm in flower, 12–20 mm in fruit, expanding at the apex, spaced 1–2 mm apart. Flowers with the calyx 3–6 mm long, the tube 1 –1.5 mm, the lobes 2 –4 + 1 –2 mm, broadly triangular, reflexed at anthesis, sparsely stellate-pubescent abaxially, glabrous adaxially with a few scattered, usually simple, trichomes along the midvein. Corolla 1.4 –1.8 cm in diameter, stellate, membranaceous, white, lobed 3 /4 of the way to the base, the lobes 7–9.5 + 3–4 mm, planar at anthesis, sparsely stellate-pubescent abaxially, glabrous adaxially, the trichomes denser at the tips and along the lobe midveins. Stamens 3.5 –5 mm; filaments to 0.5 mm; anthers 3.5 –5 + 1.5 –2 mm, oblong, the base sagittate, the apex emarginate. Ovary glabrous; style 7–8 + 0.5–1 mm, exserted beyond stamens; stigma 1–1.5 mm wide. Berries 10–12 mmindiameter, globose, green when immature, maturing white or purplish black, semitransparent, drying brown, glabrous, the pericarp thin, the mesocarp watery and held under pressure until dehiscing explosively at maturity; calyx lobes not expanding in fruit. Seeds 15–20 per fruit, ca. 2 + 1 mm, the surfaces minutely pitted. Figure 10 .

Habitat and Distribution— An herb or subshrub of dry, deciduous forests and thickets in mountainous regions from the Sierra Madre Occidental in the Mexican state of Guerrero to Honduras and Nicaragua, from 1,000–1,500 m in elevation ( Fig. 7 ).

Phenology— Flowering collections have been made in February, March, and June-October. Fruiting collections have been made in June –October.

Conservation Status— The widespread distribution and abundant populations of S. lignescens give it an IUCN Red List Status of Least Concern.

Etymology— The epithet lignescens refers to the lignescent, woody habit of the species.

Additional Specimens Examined— MEXICO. Chiapas: Mun. Tzimol, ca. 7 km SE of Comitán, ca. 3 km SE of Tzimol, 1,350 m, 7 Jul 1990 (fl, fr), Hampshire et al. 1151 (BM); Mun. La Trinitaria, 4 km Eof La Trinitaria along Mex. 190, 16 ° 08 ' N, 92 ° 02 ' W, 1480 m, 8 Jul 1990 (fl), Hampshire et al. 1154 (BM); same loc., 8 Jul 1990 (fl, fr), Hampshire et al. 1184 (BM); Las Rosas, Rancho Santa Isabel, 7 km al Nde Villa Las Rosas, 16 ° 25 ' 00 '' N, 92 ° 24 ' 00 '' W, 1642 m, 9 Aug 1998 (fl), Martínez Salas et al. 31192 (NY); Mun. Tzimol, 5 km al SO de Tzimol, 1150 m, 14 Sep 1988 (fl), Reyes Garcia & Uriquijo 794 (MEXU). Guerrero: Costa Verde, Acapulco, 16 Feb 1941 (fl), Langman 3337 (MEXU). Jalisco: La Huerta, arroyo Tapeixtes (La Mina), km 55 de la carretera Puerto Vallarta-Barra de Navidad, a 4 km al SE de la Estación de Biología, 19 ° 30 ' 00 '' N, 105 ° 03 ' 00 '' W, 50 m, 25 Jun 1985 (fl), Ayala & Lott 9 (NY); La Huerta, arroyo Maderas, antiguo camino a Nacastillo, 17.5 km de la carretera Puerto Vallarta-Barra de Navidad, 22 Aug 1985 (fl, fr), Ayala 136 (NY); La Huerta, Estación Biología “Chamela”, estación de Investigación, Experimentación y Difusión Chamela, UNAM, 26 Jul 1982 (fl), Magallanes 3650 (NY); same loc., 500 m, 3 Jul 1984 (fl, fr), Magallanes 4230 (NY). Oaxaca: Mun. Pochulta, vicinity of Concordia, San Rafael, 1000 m, 2 Mar 1937 (fl), Makrinius 530 (US).

HONDURAS. Francisco Morazán: Mun. Tegucigalpa, Río Las Canoas, ca. 5 km al Ede Tegucigalpa, 14 ° 02 ' N, 87 ° 10 ' W, 1020 m, 27 Sep 1996 (fl), Linares 3536 (MEXU); Támara Valley, between Amarateca and Támara, 1,000 m, 10 Oct 1969 (fl, fr), Molina 24551 (BM, NY, S).

NICARAGUA. Estelí: Mesas Moropotente, 12.5 km SW of Laguna Miraflor, along road to Estelí, 13 ° 11 ' N, 86 ° 17 ' W, ca. 1310 m, 23 Jun 1982 (fl, fr), Stevens 21623 (BM, NY).

Notes— The leaf upper surfaces of S. lignescens usually have a mixture of simple and stellate trichomes, and a given individual may have a mixture of hair types or have only simple trichomes adaxially. Due to the presence of intermediate hair types between simple and stellate, it is likely that the simple trichomes represent cases where the rays have been lost. Stellate trichomes always have a uniseriate, often unicellular stalk. The presence of these hairs and the shrubby habit make S. lignescens easily recognizable from the simple-haired, herbaceous species that comprise the rest of sect. Gonatotrichum.

The type of S. lignescens was not designated in the protologue. From the handwriting on the labels of the duplicates of Palmer 216, it appears that Fernald saw and used the specimens at GH, MO, NY, and US for the species description (the handwriting on the material at Fappears to be that of someone else). The material of each of these collections is excellent; however, most collections just have buds while the US specimen has open flowers, making this our choice for the lectotype.

Figures

FIG. 10. Scan of isolectotype of S. lignescens.

FIG. 7. Distribution of S. deflexum, S. lignescens, and S. manabiense.