Solanum perlongistylum G. J. Anderson, Martine, Prohens & Nuez, 2006

Anderson, G. J., Martine, C. T., Prohens, J. & Nuez, F., 2006, Solanum Perlongistylum and S. Catilliflorum, New Endemic Peruvian Species of Solanum, Section Basarthrum, Are Close Relatives of the Domesticated Pepino, S. Muricatum, Novon: A Journal for Botanical Nomenclature 16 (2), pp. 161-167 : 162-164

Solanum perlongistylum G. J. Anderson, Martine, Prohens & Nuez , sp. nov.

TYPE: U.S.A. Connecticut: cultivated at Univ. Conn. Ecol. & Evol. Biol. Conservatory, Storrs, 19 Nov. 2004, C. T. Martine 953 (holotype, CONN; isotypes, MO, MOL, NY, US, VAL) [ Peru. Huancavelica: near Montacra , quebrada border, 16 Mar. 2001, seed collection, J. Prohens & F. Nuez 51]. Figure 1A–D .

Habitus semierectus; foliola base rotunda, plerumque tria; pubescentia densa, pili longi; sine pugiotis pilis glandulosis; stylus perlongus, extendens multo ultra columnam staminalem.

Trailing or viny shrub with arching-ascending branches to 1 m long or more, internodes 20– 70 mm; stem woody or thick-herbaceous, moderately strigose when young, the older branches occasionally rooting at nodes. Leaves with mostly 3 (rarely 1 or 5) leaflets, 40–60 mm long, with petiole 10–20 mm long; leaflets lanceolate to lanceolate-elliptic, base obtuse, apex acute or acuminate, not glutinous, with moderately dense strigose vestiture of 2-celled bayonet hairs (ca. 0.8 mm) intermixed with short square gland hairs (ca. 0.08 mm) on both surfaces; gland-tipped finger hairs not present; terminal leaflet somewhat larger than the first pair of lateral leaflets, 27–44 × 14– 24 mm, petiolule 3–7 mm long; first pair of lateral leaflets 9–20 × 6–14 mm, short-petiolulate; pseudostipules present. Inflorescence an indeterminate pseudoterminal cymose raceme with 1 axis and (5)6 to 8(13) hermaphrodite flowers; pedicels 8–13 mm long, basally articulate, with dense strigose vestiture of 2- celled bayonet hairs intermixed with short square gland hairs. Corolla white or purple and fading to white, rotate, moderately reflexed, the lobes 11– 14 mm long, the sinuses 9–11 mm long, the lobe:sinus ratio about 1.4:1, glabrous or sparingly strigose adaxially, densely puberulent abaxially; calyx green, acute to acuminate, about 1/2 the length of the corolla lobes (6–7 mm long), the strigose vestiture heavy; anthers pale yellow, the apices rounded, 3.5–4.8 mm long, glabrous adaxially and abaxially, filaments 0.7– 1.3 mm long, fused for less than 1/4 of their length, with scattered stiff hairs around base; style 7.3– 12.8 mm long, sparingly to densely strigose over lower 2/3 of length, the stigma slightly capitate, exceeding staminal column by 3.6–4.4 mm. Fruits globose, mature fruits pale green or yellowish green with darker green or purple-black stripes, with darker maculae on the lighter areas, 22–27 × 23–27 mm, round in cross section, smooth, apex rounded, locules 2; soluble solids concentration 6.0%–7.5%; seeds 60 to 120 per fruit; fruits falling from plant when ripe. Pollen grains per anther ca. 133,765, pollen:ovule ratio ca. 4968:1 ( Table 1 ); plants self-incompatible; n = 12 (Martine 953, CONN).

Habitat and distribution. Collections of the species have been made in Peru at elevations around 2100–3200 m on field borders, road cuts, quebradas, and riverbanks. Local names for Solanum perlongistylum vary, as do perceptions of the edibility of the fruits. Near Montacra in Huancavelica, the fruit is known as nokai and is said to be poisonous to livestock. Locals in the area of Ocros in Ayacucho call the species alpunto and also consider the fruits inedible. However, around Ccochahuayjo, Apurimac, people consider the fruits edible and sweet, and call the species pepino de monte (Prohens, pers. obs.).

The new taxon is distinguished from morphologically similar species in Solanum sect. Basarthrum ser. Caripensia by bearing the longest styles, nearly 8.5 mm on average, versus about 6 mm for the other species with which it might be confused (i.e., the socalled Caripense complex including the widespread S. caripense (Central America to Peru) and the narrowly distributed S. filiforme (only in Peru), S. fraxinifolium (mostly in Venezuela), and S. heiseri (only in Colombia) (Anderson & Bernardello, 1991; Prohens et al., 2006)). Furthermore, the style of this new species extends beyond the staminal column by an average of about 4 mm, almost twice as much as the similar species in the Caripense complex. The flowers are generally larger as well (11–14 mm vs. ca. 8.0– 8.5 mm in S. caripense ). The anthers are lemon yellow in S. perlongistylum , versus the more orange-yellow of closely related species. The leaf hairs are long, yielding a white-downy appearance to the leaves. The hairs are about 40% longer than those of S. catilliflorum . Both of these new species bear two types of hairs: 2-celled bayonet hairs and short square gland hairs. All other species in the series have these plus a third type: gland-tipped finger hairs (these being the cause for viscid leaves in the other species). There are generally 3 leaflets, although that is not particularly distinctive, and the habit is a bit more upright, similar to (but not as upright as) S. basendopogon .

Etymology. The epithet was selected to reflect the notably long styles.

Conservation status. Estimated IUCN rank: VU. Rare and known from a limited number of localities. Total wild population still unknown.

Paratypes. U.S.A. Connecticut: cultivated at Univ. Conn. Ecol. & Evol. Biol. Conservatory, Storrs, 18 July 2005, C. T. Martine & M. R. Opel 1083 ( CONN) [ Peru, Apurimac, Ccochahuayjo, 18 Mar. 2001, seed collection, J. Prohens & F. Nuez 62], 18 July 2005, C. T. Martine & M. R. Opel 1082 ( CONN) [ Peru, near Apurimac River, Ninabamba, 17 Mar. 2001, seed collection, J. Prohens & F. Nuez 61].

Figures

Figure 1. Photographs of Solanum perlongistylum (A–D) and S. catilliflorum (E–H). —A. Flowers. —B. Form. —C. Fruits. —D. Field habit. —E. Flowers. —F. Form. —G. Fruits. —H. Field habit. Scale as indicated, except for the fruits (C & G), where each square is 10 × 10 mm.