Solanum evolvulifolium
Citation:
Bot. Gaz. 37: 211. 1904.
Type:
COSTA RICA. San José: La Palma, 1,460 m, Sep 1898 (fl, fr), A. Tonduz 12615 (lectotype, designated by Tepe & Bohs 2011, pg. 1077: GH! [GH00077489]; possible isolectotypes: CR [CR–12615], K! [K000449423, K000449424], M! [M0111204], NY! [NY00138984], US! [US00027570]).
Last edited by:
Eric J. Tepe and Lynn Bohs
Written by:
Eric J. Tepe and Lynn Bohs
Habit:
Vine, sometimes shrubby, climbing tree trunks or other vegetation. Stems slender, woody, glabrous to densely pubescent, the trichomes typically ca. 1 mm or longer, occasionally in distinct lines along stem.
Sympodial structure:
Sympodial units plurifoliate.
Leaves:
Leaves simple, the arrangement distinctly distichous, the blades 0.5–5 x 0.3–3 cm, 1–3 times as long as wide, ovate to oblong-ovate, chartaceous to coriaceous, sand-punctate, glabrous to densely pubescent on the leaf blade adaxially and abaxially, pubescent on midvein adaxially with hairs 0.2-0.5 mm, discolored, occasionally reddish below; venation pinnate, with 3–4 pairs of secondary veins, the veins densely sand-punctate; base truncate to cordate, often oblique; margins entire to undulate, revolute; apex rounded and apiculate to acute, sometimes acuminate; petioles nearly absent to 0.5 cm, glabrous to densely pubescent, densely sand-punctate. Internodes 0.5–1.5(–3.5) cm.
Inflorescences:
Inflorescences 1–15 cm long, unbranched, nearly leaf-opposed to extra-axillary, with 2-80 flowers (scars), the axes glabrous to pubescent with simple, uniseriate, curled hairs; peduncle 0.6–1.5 cm; rachis 1–14 cm; pedicels 4–10 mm in flower, green to pink, 10–15 mm in fruit, glabrous to densely pubescent, spaced nearly contiguously to 8 mm apart.
Flowers:
Flowers 5-merous, all perfect. Calyx 1.5–3 mm long, conical, the tube 1–2.5 mm long, the lobes 0.5–1.5 x 0.8–1.5 mm, deltate, rounded and minutely apiculate at tips to acute, the margins somewhat thickened, glabrous to sparsely pubescent along margins, more dense at tips of the lobes, pale green to pink; fruiting calyx minutely accrescent. Corolla 1–2 cm in diameter, 5–8 mm long, stellate, membranous, greenish, white, pink, to bluish-purple, sometimes mottled, the lobes 5–11 x 2–3 mm, lanceolate, acute at apices, glabrous adaxially and abaxially, the margins ciliate. Stamens with filaments ca. 1 mm long, glabrous; anthers 2–3 x 0.8–1.5 mm. Ovary glabrous; style 4–6 x ca. 0.25 mm, cylindrical to somewhat clavate, minutely papillose in lower 2/3; stigma truncate to somewhat capitate.
Fruits:
Fruit a berry, 0.6–1.5 x 0.6–1 cm, globose to ovoid, slightly flattened, rounded to acute at apex, glabrous, red to reddish-brown when ripe.
Seeds:
Seeds 1.5–2 mm in diameter, rounded, tan, the surface rugulose.
Distribution:
Solanum evolvulifolium occurs in Costa Rica, Panama, Colombia, Venezuela, Ecuador, and Peru as an epiphyte on tree trunks in rain and cloud forest habitats; (200–)800–2,600 m in elevation.
Phenology:
Flowering and fruiting apparently occurs year-round.
References:
Dauphin López, G. 2009, March 8. Tonduz el desconocido. Nacion. Available from http://wvw.nacion.com/ancora/2009/marzo/08/ancora1894941.html.
Tepe, E.J. & L. Bohs. (2011). A revision of Solanum sect. Herpystichum. Systematic Botany, 36, 1068-1087.
Särkinen, T., R.G. Olmstead, L. Bohs & S. Knapp. 2013. A phylogenetic framework for evolutionary study of the nightshades (Solanaceae): a dated 1000-tip tree. BMC Evolutionary Biology 13: 212. doi: 10.1186/1471-2148-13-214
Solanum evolvulifolium, a climbing species, is recognizable by its characteristic distichous leaf arrangement (Fig. 1H) and branching pattern. The main stem of this species is most often encountered climbing on tree trunks, attached with adventitious roots at the nodes; secondary branches extend away from the main stem. Higher order branches are typically distichous and arise at ca. 45 degree angles, often giving the plant a characteristic, flattened appearance. The leaves often diminish in size along a branch, occasionally to a branching point or inflorescence, and then increase in size again. The pedicels, calyx and corolla are frequently pinkish-white to greenish-pink. This species can be distinguished from other simple leaved, viny members of sect. Herpystichum by the uniformly short internodes, somewhat coriaceous leaves (instead of chartaceous or somewhat fleshy), and the flattened aspect of the branches that results from the distichous leaves.
South American collections are more variable than those from Central America in leaf shape and, especially, the degree of pubescence. The calyx lobes of Central American collections are broadly ovate and rounded apically, whereas the lobes of most South American collections are deltoid in shape and acute apically. These calyx characters, however, are not sufficiently uniform, nor are they correlated with other characters that might justify segregation of S. evolvulifolium into one or more additional species. Several extreme forms from South America are included here, and these include especially robust forms from Colombia and Ecuador and an especially pubescent form from Ecuador. It is possible that the differences merit specific status, but both forms are represented by only a few collections and are thus included within a broadly defined and variable, yet easily identifiable S. evolvulifolium. Furthermore, the three sequenced accessions of S. evolvulifolium, including one accession of the robust form and two of the standard form, form a monophyletic group together with S. crassinervium and S. loxophyllum (Fig. 4). The robust form of S. evolvulifolium is strongly supported as sister to Central American accessions of S. evolvulifolium lending support for its inclusion in a morphologically variable, yet easily recognizeable S. evolvulifolium.
There is some confusion about the numbering and collector of the lectotype collection of S. evolvulifolium. Greenman’s protologue states that the collector and number is Pittier 7413. However, the handwritten labels on the K specimens give the collector as Tonduz. They do not have a collector number, but they do have a “herb. nat. Cost. number 12615 (Herbario del Museo Nacional de Costa Rica). Nevertheless, there is sufficient overlap of label information on different specimens to determine that they are all clearly part of the same collection. All labels list Tonduz’ name and the herb. nat. Cost. number. Furthermore, it seems that Tonduz was the actual collector, but that Pittier distributed the specimens under his own set of numbers (Dauphin López 2009; B. Hammel, pers. comm.). For these reasons, we refer to the collection as Tonduz 12615.
Greenman cited two syntypes, Tonduz 12615 (as Pittier 7413) and Wercklé 11599, in his original description of S. evolvulifolium. Tonduz 12615 is chosen as the lectotype because this collection has many duplicates, whereas only a single specimen is known of the Wercklé collection. The GH specimen of Tonduz 12615 is chosen as the lectotype because Greenman was at GH in 1904 and this is likely the specimen that he used in his description of S. evolvulifolium. Furthermore, the GH specimen gives the altitude as 1460 m, the altitude stated in the protologue. The rest of the Tonduz 12615 collections report an altitude of 1542 m and therefore they are listed above as possible isolectotypes