Solanum myrsinoides D'Arcy & Rakot., Fl. Madag., Fam. 176: 115. 1994.

Knapp, Sandra & Vorontsova, Maria S., 2016, A revision of the " African Non-Spiny " Clade of Solanum L. (Solanum sections Afrosolanum Bitter, Benderianum Bitter, Lemurisolanum Bitter, Lyciosolanum Bitter, Macronesiotes Bitter, and Quadrangulare Bitter: Solanaceae), PhytoKeys 66, pp. 1-142 : 57-60

Solanum myrsinoides D'Arcy & Rakot., Fl. Madag., Fam. 176: 115. 1994. Figure 19

Type.

Madagascar. Antsiranana: partie occidentale du Massif de Marojejy (Nord-Est) de la vallée de l’Ambatoharanana au bassin supérieur de l’Antsahaberoka, 1200-1400 m, 9 Nov - 2 Dec 1959, H. Humbert & P. Saboureau 31469 (lectotype, designated here: P [P00352407]; isolectotypes: P [P00352405], P [P00352406], MO [MO-277613]) .

Description.

Liana or epiphyte growing up to 4 m above ground. Stems somewhat ribbed or winged, glabrous, the wings to 2 mm wide on herbarium specimens; new growth completely glabrous; bark of older stems longitudinally ridged (when dry), brown. Sympodial units plurifoliate, the leaves not geminate, evenly distributed along branches. Leaves simple, 10-20 (31) cm long, 2.5-4.5 (6) cm wide, linear to elliptic or obovate, thick coriaceous to fleshy and probably somewhat succulent, concolorous, glabrous on both surfaces; major veins 4-5 pairs, not easily visible, the finer venation not visible; base cuneate to rounded; margins entire, sometimes revolute in dry material; apex acute to acuminate; petiole 1-2.5 cm long, thick and fleshy, often somewhat flattened and drying with prominent wings and ridges perpendicular to the axis, glabrous, possibly twining. Inflorescences terminal, at the apex of terminal branches or slender lateral branches, 7-11 cm long, furcate or occasionally unbranched, with 2-6 flowers; peduncle 4-9 cm long, less than 1 mm diameter at the base, much thinner than the stem, glabrous; pedicels 1.5-2.5 cm long, apically dilated, glabrous, drying ridged, articulated in the lower ⅓, 0.1-0.8 cm from base; pedicel scars prominent peg-like stumps, darker distally, irregularly spaced 3-10 mm apart. Buds oblong, the corolla strongly and long-exserted from the calyx tube. Flowers 5-merous, apparently all perfect. Calyx 1-2 mm long, ca. 6 times shorter than the corolla at anthesis, broadly cup-shaped, the lobes less than 1 mm long, 2-3 mm wide at base, broadly deltate, obtuse at the tips, glabrous with tufts of papillae at the lobe apices and some papillae along the margins. Corolla ca. 2 cm in diameter, white to violet-purple, stellate, lobed almost to base, the lobes 10-15 mm long, 2.5-3 mm wide, narrowly deltate to long-triangular, both surfaces glabrous, the margins densely papillate, the tips cucullate. Stamens equal; filament tube ca. 0.5 mm long; free portion of the filaments ca. 1.5 mm long, glabrous; anthers ca. 7 mm long, ca. 1.5 mm wide, ellipsoid, tightly connate, papillate abaxially, poricidal at the tips, the pores slightly smaller than anther apices, clearly delineated and not lengthening with age. Ovary conical, glabrous; style 8-9 mm long, protruding 1-2 mm beyond the anthers, filiform, straight, glabrous; stigma clavate, the surface smooth. Fruit a long-ellipsoid, fusiform or pyriform berry, (1.5)3-4 cm long, 1-2 cm diameter at maturity, with an apical beak 2-5 mm long, basally rounded or the base narrowing and the berry fusiform, ripe fruit colour not known, mature pericarp glabrous, the flesh thick and the fruit apparently spongy or woody, no seeds borne in the elongate apex; fruiting pedicels ca. 1.6 cm long, 1-2 mm diameter at the base, spreading; fruiting calyx lobes minute, becoming reflexed as the fruit enlarges. Seeds 5-8 per berry, 5-6 mm long, 3-4 mm wide, flattened reniform and imbedded in thick pulp, dull golden-yellow, the surfaces minutely pitted, the testal cells rectangular (? - only seen in immature seeds) in outline.

Distribution

(Figure 20 ). Endemic to northeastern Madagascar, in Toamasina and Antsiranana provinces.

Ecology and habitat.

Wet montane forests; 500-1500 m elevation.

Common names and uses.

None recorded.

Preliminary conservation status

( IUCN 2014). Vulnerable (VU B1a,b iii); EOO 7,482 km2 (VU), AOO 52 km2 (EN). Solanum myrsinoides is known from fewer than 10 locations, all in a restricted area around Antogil Bay in northeastern Madagascar. Its population density may be underestimated as it is a rarely collected canopy liana or epiphyte. It occurs in several protected areas in the region and so is not assessed here as Endangered as the small AOO might warrant.

Discussion.

Solanum myrsinoides is a distinctive wet forest endemic. Its large coriaceous or fleshy leaves, often epiphytic habit and apically elongated fruit are unusual in Solanum . Solanum myrsinoides seems to grow as a liana but can lose connection with the ground and survive as an epiphyte as high as 4 m in the canopy. The stems of Solanum myrsinoides are often winged. The thick petioles are flexuous and have a wrinkled woody texture when dry; it seems likely that these are used for climbing. Size and shape of the leaves is highly variable between collections and probably therefore plants. The peduncle and rachis are long and slender, in contrast to the thick stems (Fig. 19 ). It is the only Solanum species in Madagascar that is completely glabrous on all vegetative parts, with nothing but small papillae on the apices of the calyx and corolla lobes. D’Arcy and Rakotozafy (1994) report that these trichomes are sometimes branched, but we have not seen this in any of the specimens we have examined.

Solanum myrsinoides is unlikely to be confused with another species of Solanum . Some large leaved individuals of Solanum truncicola are highly reminiscent of Solanum myrsinoides in their leaves and habit, perhaps reflecting common adaptation to montane wet forest understorey. Solanum myrsinoides can be distinguished by its calyx lobes that are less than 1 mm long (versus 4-11 mm long), inflorescences with 2-6 flowers (versus 1-2 flowers), and distinct slender peduncle 4-9 cm long (versus peduncle absent). The distribution of the two species does not overlap; Solanum myrsinoides occurs at lower elevations further north.

The developing fruit of Solanum myrsinoides has a globose basal part and a clearly distinct elongated apical beak that gradually tapers to a point (Fig. 19 ). At maturity the basal globose part narrows to produce a woody (in dry specimens) ovoid shape; sometimes the basal part of the fruit also narrows so the berry is fusiform (spindle-shaped) and tapers at both ends. Among the non-spiny Solanum species endemic to Madagascar, similar apically pointed fruits occur in Solanum betroka , Solanum imamense , Solanum sambiranense , and Solanum truncicola ; globose berries have been observed in Solanum imamense , Solanum madagascariense , and Solanum trichopetiolatum . The thick, possibly spongy flesh seen in Solanum myrsinoides is not apparent in other Madagascar solanums, but these species are rarely collected in fruit; further field observations are necessary.

A holotype and an isotype are cited from P. There are three duplicates of the type collection at P and a single sheet was not selected at the time of description. P00352407 is marked “type” with a label attached over (and apparently thus after the determination) D’Arcy’s determination slip, indicating that perhaps it is the one D’Arcy and Rakotozafy intended as the holotype. We here select this sheet as the lectotype to avoid ambiguity because there is no evidence of the author’s selection of a particular sheet as holotype (see McNeill 2014).

Selected specimens examined.

Madagascar. Antsiranana: Sambava, pentes orientales du Massif de Marojejy, (N-E), a l’ouest de la riviere Manantenina , affluent de la Lokoho, 15 Dec 1948, Humbert 22504 (K, Px2); Ambatosoratra, Vallée de la Lokoho (Nord-Est), mont Ambatosoratra au Nord d'Ambalavoniho et de Belaoka, Jan 1949, Humbert & Cours 22863 (MO, P); contreforts occidentaux du massif de Marojejy (Nord-Est) près du col de Doanyanala (limite des bassins de la Lokoho et de l’Andraronga, 1949, Humbert 23142 (P); Reserve Naturelle de Marojejy , along the trail to the summit of Marojejy Est, N of Mandena, 3 Dec 1989, Miller & Randrianasolo 4675 (MO, TAN); Préfecture d’Antalaha, Sous-Préfecture d’Andapa, commune rurale de Bealampona, sud-ouest d’Andapa, Réserve Spéciale d’Anjanaharibe-Sud, village d’Andranotsarabe, suivant la route Nationale d’Andapa-Bealanana de la piste vers à l’ouest, Ambatomainty, Camp No. 2, 3 Nov 1994, Ravelonarivo & Rabesonina 475 (MO); limite entre Anjialavabe et Doany, Andapa, deuxième montagne d’Ankarongameloka, Ravelonarivo 1889 (P) . Toamasina: Marovovonana, Befotsila Camp, 1 Sep 2004, Antilahimena 2694 (MO, P); Masoala National Park , N ridge of Ambohitsitondroinan’Mahalevona, just below summit, ESE of village of Mahalevona, 23 Feb 2003, Lowry et al. 6120 (MO, TAN); Antongil, environs de la Cave, baie d’Antongil, Aug 1912, Perrier de la Bâthie 8718 (P); Masoala peninsula, Ambanizana , ' S Trail’ (S of Androka river) climbing into hills SE of Ambanizana, 1 Nov 1992, Schatz et al. 3391 (MO, P) .

Figures

Figure 19. Solanum myrsinoides D'Arcy & Rakot. A Flowering branch B Open flowers C Berry showing tapering at both ends (based on: A Humbert & Saboureau 31429 B Humbert 22253 C Cours 3326). Adapted from D'Arcy and Rakotozafy (1994) with permission of Museum National d'Histoire Naturelle.

Figure 20. Distribution of Solanum myrsinoides D'Arcy & Rakot.