Solanum scuticum
Citation:
Brittonia 58: 350. 2006.
Type:
Brazil. Bahia: sin. loc., 1830, Salzman 389 (holotype, G-DC [F neg. 6808, photos: BH, F, MO, NY, US]; probable isotypes (without number but “nov. sp.”): K-2 sheets, W). Non S. tabaccifolium Vell., 1825.
Last edited by:
Nee, M.
Written by:
Nee, M.
Habit:
Shrubs 1.5–3 (–4) m high, the internodes 2–9 (–11) cm long. Stems moderately to densely stellate-tomentose with yellow-ferruginous porrect stellae, the stipes of various lengths, 0.4–1 mm long, the stellae 0.4–0.8 mm broad, with 6–8 rays, the midpoint much shorter than the rays, tardily and irregularly glabrescent leaving a contrast of the remaining tomentum with the very dark stem in dried material; stems usually armed with straight, broad-based prickles to 5 mm long.
Sympodial structure:
Sympodia bifoliate, geminate.
Leaves:
Leaves simple, the blades of major leaves 15–23 × 7–12 cm, ca. 2–2.5 times as long as wide, broadly to narrowly ovate to elliptic, thick-chartaceous, the minor leaves half as large to nearly as large as the majors, green and moderately and evenly stellate-tomentose above with 4–8-rayed stellae 0.3–0.5 mm broad, mostly sessile and not overlapping, but on the major veins more densely set and more of them stipitate, densely and pale stellate-tomentose below with mixed sessile and stipitate stellae forming several layers, the stipitate stellae like those of the stem; 5–7 principal lateral veins on each side of midvein; base acute to truncate or subcordate; margin usually entire, but often irregularly repand or with 1–4 shallow lobes per side; apex acute to attenuate; blade usually unarmed, or rarely with a few acicular prickles to 9 mm long on the major veins abaxially and more rarely with prickles on the midrib adaxially; petioles 1–1.5 (–4.5) cm long, stellate-tomentose like the stem, unarmed or rarely with a few prickles like those on the blade.
Inflorescences:
Inflorescences 1.5–2.5 cm in flower, 2.5–4.5 (–8) cm in fruit, lateral, extra-axillary, 2–3-branched, more rarely simple, with ca. 20–50 flowers, all the flowers apparently fertile or potentially so, the axes stellate-tomentose with hairs like those of the stem, unarmed; peduncle 0.3–0.8 cm long, the branches 1.5–5.5 cm long; pedicels 6–8 mm long in flower, to 1.1–2 cm long and 2 mm in diameter in fruit, spaced 2.5 mm apart, articulated at the base.
Flowers:
Flowers homostylous, 5-merous. Buds narrowly ovoid, densely and finely stellate-tomentose. Calyx 3–3.5 mm long, the tube 3 mm long, in bud appearing nearly truncate with short-caudate lobe tips 0.7–0.9 mm long, soon splitting in the sinuses and then the lobes ovate or oblong, 2.5–4 × 2–2.5 mm in fruit, stellate-tomentose abaxially, glabrous adaxially, unarmed. Corolla 2–3 cm in diameter, 1.5 cm long, stellate with well-developed glabrous interpetalar tissue, white, the tube ca. 5 mm long, the lobes 10 × 4 mm, the midrib lanceolate, 10.5–11 × 2–2.5, finely stellate-tomentose abaxially, glabrous adaxially except for a few minute sessile stellae on the midvein. Stamens with filaments 0.9–1 mm long; anthers 6–8 × 1–1.2 mm, free, slender, attenuate, yellow, with minute apical pores, the pores directed distally. Ovary with minute weak sessile stellae near the apex, soon glabrescent; style 8–10 mm long, filiform, glabrous; stigma capitate.
Fruits:
Fruit a berry, 1.4–1.7 cm in diameter, globose, the immature fruits green, maturing yellow-orange, glabrous.
Seeds:
Seeds 2.3–2.5 × 1.5–1.9 mm, flattened-reniform, yellow, the surface minutely pitted, nearly smooth.
Chromosome number:
Not known
Distribution:
It is probably not uncommon on the pre-Cambrian (“Brazilian”) shield area of eastern Depto. Santa Cruz, although few collections have yet been made there. It is known from only a single collection from Paraguay. Throughout much of southern and eastern Brazil it is common; from near sea level to at least 1100 m.
Phylogeny:
Solanum scuticum belongs to subgen. Leptostemonum and is a quite typical member of sect. Torva (Nee, 1999).
References:
Nee, M. 1999. Synopsis of Solanum in the New World.
Pp. 285–333 in M. Nee, D. E. Symon, R. N. Lester & J. P. Jessop (eds.), Solanaceae IV: Advances in Biology and Utilization. Royal Botanic Gardens, Kew.
Solanum scuticum is the common weedy representative of sect. Torva throughout much of Brazil south of the Amazon; it is common in second growth, roadsides and pastures.
Several widely distributed collections were identified as S. asperolanatum Ruiz & Pav., but that is a species of much higher elevations in the Andes, is more robust in all respects, especially the peduncle which is usually more than 3 cm long.
This species is very similar to S. rudepannum in having very yellowish ferruginous inflorescences, stems and leaves. The calyx in bud stage, however, is much shorter and appears truncate, with lobes very short with only the caudate tip being obvious.