Citation:
Bot. Jahrb. Syst. 28: 473. 1900.
Type:
TANZANIA. Morogoro District, Ukutu, 1898, W. Goetze 112 (lectotype, designated by Vorontsova & Knapp Syst Bot Monog in press: K! [K000413984]).
Written by:
Maria S. Vorontsova & Sandra Knapp
Habit:
Erect shrub, 0.5-1 m, unarmed. Young stems terete, densely stellate-pubescent and unarmed, with multangulate, sessile or variously stalked trichomes, the stalks to 0.1 mm, the rays 12-20, 0.05-1.5 mm long, the midpoints ca. same length as the rays or shorter, with minute simple hairs; bark of older stems glabrescent to moderately stellate-pubescent, gray to yellow-gray.
Sympodial structure:
Sympodial units difoliate, not geminate.
Leaves:
Leaves simple, the blades 8-17 cm long, 3-7 cm wide, 2-2.5 times longer than wide, elliptic, membranous, drying concolorous, dark red-brown to yellow-green, glabrescent on both surfaces, with porrect to multangulate, sessile trichomes, the rays 4-8(-14), 0.05-0.2 mm long, the midpoints ca. same length as the rays or shorter, with minute simple hairs; the primary veins 6-8 pairs, the tertiary venation often visible to the naked eye on the abaxial side of the leaf; base attenuate; margins entire or very shallowly undulate; apex obtuse to acute or acuminate; petiole 1-4.5 cm long, 1/6-1/4 of the leaf blade length, sparsely stellate-pubescent to glabrescent.
Inflorescences:
Inflorescences apparently terminal or lateral, 2.5-4.5 cm long, branched once, sometimes not branched, with 8-15 flowers, ca. 5 flowers open at any one time, moderately to densely stellate-pubescent; peduncle 3-17 mm long; pedicels 0.4-0.8(-1) cm long, erect to recurved, articulated at the base, moderately stellate-pubescent to glabrescent; pedicel scars spaced less than 1 mm apart.
Flowers:
Flowers 4-5-merous, apparently all perfect. Calyx 2.5-4.5(-6) mm long, glabrescent, unarmed, the lobes 1.8-2.5 mm long, deltate, apically long-acuminate. Corolla 0.9-1.6 cm in diameter, pale mauve to mauve, sometimes white with mauve midveins, stellate, lobed for ca. 3/4 of the way to the base, the lobes 4-7(-8) mm long, 1.5-2.5 mm wide, narrow-deltate, spreading, moderately stellate-pubescent to glabrescent abaxially, the trichomes porrect, sessile, the rays 4-8, 0.05-0.2 mm long, the midpoints ca. same length as the rays or shorter. Stamens equal, with the filament tube 1-1.5 mm long, the free portion of the filaments 0.8-1.5 mm long; anthers 2.5-4 mm long, connivent to spreading, tapering, poricidal at the tips. Ovary with minute glandular hairs on the upper 1/3; style 0.5-0.8 cm long, filiform, almost straight or curved at the tip, glabrous.
Fruits:
Fruit a spherical berry, 4-13 per infructescence, 0.7-1.1 cm in diameter, the pericarp smooth, evenly green when young, bright red at maturity, glabrous; fruiting pedicels 0.8-1.5 cm long, 0.3-0.8 mm in diameter at base, woody, erect; fruiting calyx lobes not elongating, ca. 1/4 the length of the mature fruit, reflexed.
Seeds:
Seeds ca. 10-20 per berry, 3.6-4.8 mm long, 2.8-4 mm wide, flattened-reniform, dull yellow to orange-brown.
Phenology:
Flowering and fruiting throughout the year.
Solanum goetzei is a small shrub with unusually large seeds and fine long-acuminate calyx lobes. There is a sharp contrast in the quantity of indumentum between the white densely stellate-pubescent stems and the dark, almost glabrous leaves. There are 12-20 rays on the multangulate stem trichomes, with the bases of the rays distributed along a 0.1-0.2 mm length of the trichome central axis. Leaf trichomes are porrect with only 4-8 rays, and the trichomes on petioles and bases of young leaves are intermediate between these. Cell outlines on the seed epidermis indicate that individual cells are significantly larger than those in small-seeded species, while the number of cells remains roughly the same.
The populations in coastal Kenyan and Tanzania are largely morphologically uniform but collections made in inland parts of Tanzania are somewhat morphologically distinct; Greenway et al. 13319 (K) and Sitoni MSB149 (K) have wider lobed leaves, and Luke et al. 10456 and Bidgood & Keeley 322 have a longer rachis and obtuse calyx lobes.
Solanum goetzei is frequently confused with the bristle-free variants of the highland S. schumannianum. Solanum goetzei and S. schumannianum occupy largely the same geographical region of Kenya and Tanzania, have similar shrubby habit, entire leaves, and large seeds 3.5-4.5 mm long. Solanum schumannianum can be distinguished by its greater height of 1.5-3 m (versus 0.5-1 m height of S. goetzei), leaves 2.5-3.5 times longer than wide (versus leaves 2-2.5 times longer than wide in S. goetzei), inflorescence branched more than once, with a peduncle 20-60(100) mm long and rachis 1.5-5(7) cm long (versus not branched or branching once, with a peduncle 3-17 mm long and rachis 0.3-1.5 cm long in S. goetzei), and (5)10-20 rays on each trichome on the leaves (versus 4-8(14) rays on each trichome on the leaves in S. goetzei). These two species are unlikely to be truly sympatric as S. schumannianum only grows above 1800 m in elevation, while S. goetzei has not been recorded any higher than 800 m in elevation.
Solanum goetzei resembles two West African members of the Giganteum clade, the Angolan endemic S. pauperum and the more widespread S. anomalum. Solanum goetzei and S. pauperum share plain appearance, lack of prickles, entire leaves with attenuate bases, and similar trichome morphology; S. goetzei can be separated by its peduncle 3-17 mm long (versus peduncle less than 1 mm long in S. pauperum), 8-15 flowers per inflorescence (versus 4-8 flowers per inflorescence in S. pauperum), long-acuminate calyx lobes (versus acute calyx lobes in S. pauperum), petioles 1/6-1/4 as long as the adult leaves (versus petioles 1/3-2/3 as long as the adult leaves in S. pauperum), and seeds 3.6-4.8 × 2.8-4 mm (versus seeds 2.8-3.5 × 2.5-3.5 mm in S. pauperum). Solanum goetzei and S. anomalum share a lowland habitat, condensed inflorescences, an glabrescent elliptic leaves; S. goetzei can be distinguished by its unarmed habit (versus deltate prickles on most specimens of S. anomalum) and seeds 3.6-4.8 × 2.8-4 mm (versus seeds 2.5-2.8 × 2-2.5 mm in S. anomalum).
The chosen lectotype of S. goetzei is the only known extant duplicate of the three collections cited in Dammer’s protologue, and that collected by the person for whom the species is named. Udo Dammer worked at Berlin, and it is likely that all the specimens he examined were destroyed. We have found no duplicates of the other two syntypes F. Stuhlmann 127 and Fischer 409 and so have chosen the only duplicate of Goetze 112 we have found as the lectotype. The lectotype we have chosen for S. bagamojense follows the unpublished choice made by Richard Lester; both duplicates (BREM and W) were cited in the protologue.