Solanum mortonii Hunz., Kurtziana 12-13: 133, fig. 1. 1979.

Knapp, Sandra, Sagona, Eva, Carbonell, Anna K. Z. & Chiarini, Franco, 2017, A revision of the Solanum elaeagnifolium clade (Elaeagnifolium clade; subgenus Leptostemonum, Solanaceae), PhytoKeys 84, pp. 1-104 : 36-37

5. Solanum mortonii Hunz., Kurtziana 12-13: 133, fig. 1. 1979. Figures 2F , 3 C, D , 11

Type.

Argentina. Catamarca: Dpto. Capayán, San Pablo , between Concepción and Huillapima, 700 m, A. Hunziker & R. Subils 22764 (lectotype, designated by Chiarini 2013, pg. 221: CORD [CORD00004247]; isolectotype: CORD [CORD00004248]) .

Description.

Erect rhizomatous shrub, to 1 m tall. Stems erect, woody, armed or unarmed; young stem densely stellate-pubescent, the trichomes multangulate, translucent, short-stalked, the rays 10-12, ca. 0.5 mm long; prickles if present 5-6 mm long, needle-like and straight, pale yellowish brown; bark smooth, brown or yellowish brown from persistent pubescence. Sympodial units difoliate, not markedly geminate. Leaves simple, (2-)4-9 cm long, (1-)2-4 cm wide, elliptic, ca. 3 times longer than wide, discolorous, drying yellowish green to greyish green; adaxial surfaces densely stellate-pubescent but the leaf blade tissue visible, the trichomes multangulate, translucent, sessile, the rays 10-12, ca. 0.5 mm long; abaxial surfaces more densely pubescent with similar multangulate trichomes; principal veins 5-7 pairs, impressed adaxially, flat abaxially, spreading at ca. 45° to the midvein, the tertiary venation usually visible in dry material; base truncate to slightly cordate, often somewhat oblique; margins shallowly lobed, the lobes 4-7 on each side, of varying sizes, becoming smaller towards the leaf apex, the sinuses extending only 1/4 or less of the distance to the midvein, triangular; apex acute to somewhat rounded, rarely obtuse; petiole 1-2 cm long, densely stellate-pubescent like the young stem, unarmed. Inflorescences terminal or lateral, to 6.5 cm long, with up to 10 flowers, unbranched; peduncle 1.5-3 cm long, densely pubescent with multangulate trichomes like those of the stems; pedicels 0.4-1 cm long, ca. 1.5 mm in diameter, robust, articulated less than 0.5 mm from the base, densely pubescent like the leaf blade; pedicel scars prominent, spaced ca. 0.5 cm apart. Buds turbinate, the corolla strongly exserted from the calyx tube prior the anthesis. Flowers 5-merous, strongly heteromorphic and the plants andromonoecious, only the basal flower perfect (hermaphroditic), the distal flowers functionally staminate and short-styled. Calyx conical or cup-shaped, the tube 5-6 mm long, strongly keeled, the lobes 7-10 mm long, ca. 1.5 mm wide at base, subulate, densely pubescent abaxially with multangulate trichomes. Corolla 3-3.5 cm in diameter, pentagonal, pale lavender, drying pale brown, barely lobed, interpetalar tissue abundant, the lobes ca. 0.2 cm long, ca. 0.1 cm wide, mere acumens, densely pubescent with multangulate trichomes abaxially along the midveins and surfaces exposed in bud. Stamens equal or very slightly unequal and the adaxial anthers slightly shorter; filament tube ca. 0.5 mm, free portion of the filaments ca. 2 mm; anthers 7-12 mm long, free, occasionally very slightly unequal, poricidal at the tips, the pores about the same diameter as the anther apices, clearly delineated, the anther surface smooth to finely papillose. Ovary globose, glabrous or minutely glandular puberulent; style of hermaphroditic flowers ca. 1 cm long, glabrous; stigma capitate, papillose. Fruit a globose berry, 1 per infructescence, ca. 2 cm in diameter when dry, the pericarp thin, smooth, glabrous, light green, when immature with dark stripes or marbled pattern, drying dark brown or brown-reddish and shattering; fruiting pedicels 1-1.7 cm long, ca. 1.5 mm in diameter at base, ca. 2.5 mm at apex, woody, erect, sparsely armed with straight yellowish red prickles or unarmed; fruiting calyx somewhat accrescent, to 2 cm long, the lobes covering up to 1/3 of the mature fruit, usually unarmed, if prickly the prickles needle-like and straight. Seeds ca. 40 per berry, 4-5 mm long, 3-4 mm, flattened, reniform-rounded, black, the surfaces minutely pitted. Chromosome number: not known.

Distribution

(Figure 12 ). Solanum mortonii is endemic to northern Argentina in the Province of Catamarca at 600 to 1000 m elevation.

Ecology and habitat.

Like some other members of the group, S. mortonii has rhizomatous stems (see Fig. 4C ) and is apparently clonal; it grows on rocky shaded or open banks in dry forests and can form large colonies.

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2016). EN (Endangered). EOO = 1,115 km2 (EN - Endangered); AOO = 32 km2 (EN - Endangered). Solanum mortonii has a very narrow distribution along the Sierra de Ambato and is not common where it occurs. It does, however, appear to reproduce vegetatively through underground stems, so may persist well within this narrow range.

Discussion.

Solanum mortonii is a striking species with dense greyish silvery pubescence. It is sympatric with S. elaeagnifolium , and differs from that species in its multangulate, rather than lepidote, trichomes, its broader leaves and strongly andromonoecious habit. This species is restricted to very small area in the eastern part of Catamarca province, Argentina. During attempts to germinate seeds in order to perform mitotic chromosome counts number from rootlets, all seeds collected proved to be inviable. This suggests that S. mortonii has some type of reproductive abnormality or that seeds have very time-limited viability.

Specimens examined.

Argentina. Catamarca: Capayán, San Pablo, a 1 km saliendo San Pablo rumbo a Concepción, 23 Feb 2003, Barboza et al. 633 (CORD); Capayán, San Pablo, a unos 100 m de la Iglesia San Pablo rumbo a Huillapima, 23 Feb 2003, Barboza et al. 639 (CORD); Capayán, subiendo a la Cuesta de los Angeles, entre km 12/13, 24 Feb 2003, Barboza et al. 644 (CORD); Capayán, San Pablo, pasando el Río (vado) de San Pablo, 10 Feb 2012, Barboza et al. 3437 (BM, CORD); Capayán, San Pablo, entre la Iglesia y el Río (vado) de San Pablo, 10 Feb 2012, Barboza et al. 3438 (BM, CORD); Capayán, desde Miraflores rumbo a Los Angeles, a 19 km de Los Angeles , 10 Feb 2012, Barboza et al. 3439 (BM, CORD); La Paz, El Potrero, 23 Apr 1947, Brizuela 1181 (W); Capayán, Concepción, Quebrada El Totoral, 10 Jan 1909, Castillón 1030 (LIL); Capayán, San Pablo, Sierra Ambato, 3 Feb 1910, Castillón 1628 (LIL); Capayán, Sierra de Ambato , falda E, subiendo por la Quebrada de Simbolar desde Concepción hacia La Abuelita, 21 Nov 1965, Hunziker et al. 18322 (CORD, NY, US); Capayán, Sierra de Ambato , falda E, subiendo por la cuesta entre Miraflores y Los Angeles, 27 Nov 1965, Hunziker et al. 18333 (CORD, NY, US); Capayán, Sierra de Ambato , falda E, subiendo por la cuesta entre Miraflores y Los Angeles, 16 Mar 1972, Hunziker 21889 (CORD); Capayán, Sierra de Ambato , falda E, subiendo por la cuesta entre Miraflores y Los Angeles, 16 Mar 1972, Hunziker 21895 (CORD, NY) .

Figures

Figure 2. Flowers of members of the Elaeagnifolium clade. A Solanum elaeagnifolium, with divergent anthers of approximately equal size and shape (Argentina, Mendoza, Knapp et al. 10470) B Solanum homalospermum (Argentina, Catamarca, Chiarini et al. 505) C Solanum hindsianum (cultivated in Arizona) D Solanum houstonii, hermaphroditic flower and strongly curved buds (Mexico, Yucatan, Pena-Chocarro et al. 407) E Solanum houstonii, staminate flower (Mexico, Queretaro, Ochoterena et al. 976) F Solanum mortonii (cultivated in Cordoba; from Barboza et al. 644). Photographs A, D, E by S. Knapp; B, F by F. Chiarini; C by Eugene Sturla.

Figure 3. Fruits of members of the Elaeagnifolium clade. A Solanum elaeagnifolium, immature berries with green mottling (Argentina, Cordoba, Barboza et al. 3434) B Solanum elaeagnifolium, mature fruit with sticky tan seeds (Argentina, Cordoba, Barboza et al. 3435) C Solanum mortonii, immature fruit exerted from the calyx (Argentina, Catamarca, Barboza et al. 3439) D Solanum mortonii, mature fruit exerted from the calyx (Argentina, Catamarca, Barboza et al. 3438) E Solanum houstonii, immature fruit enclosed in accrescent calyx (Mexico, Queretero, Ochoterena et al. 976) F Solanum houstonii, mature fruit enclosed in accrescent calyx with black seeds (Mexico, Queretero, Ochoterena et al. 976). Photographs by S. Knapp.

Figure 4. Habitats of members of the Elaeagnifolium clade. A Solanum elaeagnifolium, old stems with persistent berries and young new stems from underground rhizomes (Argentina, Mendoza, Knapp et al. 10470) B Solanum houstonii on rocky slope (Mexico, Queretaro, Ochoterena et al. 976) C Solanum mortonii, plant dug up showing extensive underground stems (Argentina, Catamarca, Barboza et al. 3437) D Solanum mortonii, large population on rocky slopes (Argentina, Catamarca, Barboza et al. 3437). Photographs by S. Knapp

Figure 11. Lectotype of S. tridynamum Dunal. Unpublished drawing by T. F. Node-Veran (1773 - 1852) based on an illustration of Sesse and Mocino (MPU 310713). Reproduced with permission of the Universite de Montpellier - Herbier MPU (Service de Patrimoine Historique); copyright Universite de Montpellier - Herbier MPU (SPH).

Figure 12. Distribution of S. houstonii and S. mortonii.