Solanum igniferum, Gouvea

Gouvêa, Yuri & Stehmann, João, 2019, A Revision of the Solanum asterophorum Species Group (subg. Leptostemonum), Systematic Botany 44 (1), pp. 210-232 : 226-228

2. SOLANUM IGNIFERUM Gouvea ˆ& Stehmann, Phytotaxa 288: 121. 2016. Figure 3 , A–G.

Type: Brazil. Esp´ırito Santo: Mun. S~ ao Bento de Urania ˆ, Estrada que liga a rodovia BR-262 a S~ ao Bento de Urania ˆ, borda de Floresta Ombrófila Densa secundária, beira de estrada, 20°27, 10 ̎ ʺS, 40°54, 16 ̎ ʺW, 979 m, 27 April 2015 (fl, fr), Y.F. Gouvˆea & J.R. Stehmann 164 (holotype: BHCB 2 sheets [ BHCB026909 , BHCB026910 ]!; isotypes: [ BM, RB]).

Shrubs up to 2 m, the branches spreading; young stems terete, densely stellate-tomentose; the trichomes orangecolored to ferruginous, porrect, short- to long-stalked, the long ones less frequent, the stalks 0.03–0.4 mm long, multiseriate, 2–4 cells wide, the rays (4–)6–8(–10), 1-celled, unequal in length, the midpoints 1-celled, poorly developed, up to ¼ of size of the rays, oblique; moderately to sparsely armed, the prickles 1.8–4.5 mm long, 2–5 mm wide at base, recurved, flattened, stramineous at base becoming ferruginous towards the apex, with stellate trichomes like those of the stems and some small, subsessile, glandular trichomes at base, these often drying dark; bark of older stems glabrescent to moderately stellate-tomentose, dark green to dark brown. Sympodial units difoliate, geminate, the leaves of a pair anisophyllous. Leaves lobed, repand in large-leaved plants; the major leaves 14–22(–30) cm long, 8–17(–23) cm wide, ovate to obovate; base cuneate to subcordate, generally asymmetric; margins shallowly to deeply lobed, the lobes deltate, to 2.5 cm long, to 6.5 cm at base, acuminate to roundish apically, (1–)2–8 on each side; apex acute to obtuse; primary veins 6–9 pairs; minor leaves 7–12 cm long, 4–7.5 cm wide, elliptic to nearly circular; base acute to rounded, generally symmetric; margins entire to shallowly lobed, the lobes deltate, 0–3 on each side, to 1 cm long, to 2.5 cm wide at base; apex acute to obtuse-rounded; primary veins 5–6 pairs; major and minor leaves all membranaceous to chartaceous, discolorous, drying green to dark brown with the indumentum giving a superficial yellowish orange-colored appearance on the adaxial surface, and grayish-green to yellowish-green on the abaxial surface; the adaxial surface densely stellate-tomentose, the epidermis always visible, the trichomes porrect to antrorse, sessile to longstalked, the stalks to 2.5 mm long, multiseriate, 3–4 cells wide, the rays (3–)4–8, 1-celled, unequal in length, the midpoints 1-celled, from ¾ to the same length as the rays, usually straight; forked, sessile to short-stalked trichomes rarely present; the longer trichomes more densely distributed along the midrib and primary veins, these orange-colored to ferruginous, contrasting with the shorter, hyaline to stramineous ones; the abaxial surface densely stellate-tomentose, the epidermis always visible, the trichomes like those of the leaf adaxial surface, but with stalks to 0.24 mm long, and midpoints up to ¾ of size of the rays, the longer, usually ferruginous to orange-colored trichomes more densely distributed along the midrib and primary veins, less frequent than on the adaxial surface, these contrasting with the most frequent shorter, hyaline to stramineous ones; unarmed to moderately armed along the midrib and the primary veins on both surfaces, the prickles straight, flattened, 1–7.5 mm long, 0.5–2.5 mm wide at base, 0–25 above and 0–10 beneath; petiole of major leaves 2–4.5 cm, densely stellate-tomentose with stellate trichomes like those of the stems, the prickles 0–5, straight; petiole of minor leaves 1–2.8 cm, densely stellatetomentose with stellate trichomes like those of the stems, the prickles 0–4; leaves of juvenile plants larger, more densely armed and more lobed, becoming smaller, less prickly with fewer lobes in older plants. Inflorescence a reduced monochasial cyme, 1.5–27 mm long, unbranched, leaf-opposed or nearly so, with (4–)7–15(–19) flowers, 1(–2) flowers open at a time; inflorescence axis (peduncle plus rachis) densely stellatetomentose with stellate trichomes like those of the stems, unarmed; peduncle nearly obsolete to 7 mm long; rachis 1.5–20 mm; pedicel insertion points more widely spaced proximally, 0–3.8 mm apart, usually not overlapping, if so only the more distal ones; pedicels straight or nearly so, with the flower buds erect to spreading before anthesis, 9–16 mm long and straight at anthesis, sometimes geniculate distally, articulated at base, unarmed, densely stellate-tomentose, the trichomes all ferruginous to orange-colored or mixed with hyaline to stramineous trichomes, porrect, short- to longstalked, the stalks 0.04–0.4 mm long, multiseriate, 2–3 cells wide, the rays (6–)8(–11), 1-celled, unequal in length, the midpoints 1-celled, poorly developed, up to ½ of size of the rays. Flowers 5-merous, heterostylous, basal flowers longstyled and hermaphroditic, short-styled and functionally male flowers produced distally in the inflorescence (see Sexual Expression and Inflorescence). Calyx tube obconic, 5–7 mm long, with the midrib of the calyx lobes more or less prominent abaxially (externally), from the calyx base towards the lobe apices, densely stellate-tomentose with trichomes like those of the pedicels, prickles 0–10; calyx lobes narrowly oblong, elliptic, or lanceolate, 2.5–7(–9) mm long, often unequal in length, 1.2–2.5(–2.8) mm wide, the apices acuminate to rounded. Corolla 3–3.8 cm in diameter, white to purplishwhite, stellate, with well-developed and wavy interpetalar tissue, lobed for 1/3 to 3/5 of its length, the lobes 6.5–10.5 mm length, 7.6–14 mm wide, rounded to deltate, apiculate at the apex, densely stellate-tomentose along the whole length abaxially, the trichomes usually ferruginous, porrect to multiangulate, sessile to short-stalked, multiseriate, 2–4 cells wide, the rays up to 12, tortuous, usually forming a crab-like shape rather than a circle, the midpoints 1-celled, ½ to the same length of the rays, the adaxial surface densely stellatetomentose at the apex with trichomes like those of the abaxial surface, becoming gradually less dense towards the base, the basal half glabrous or nearly so, the lobe tips usually cucullate and reflexed at anthesis. Stamens equal; filament tube 1.5–2.3 mm long; free portion of the filaments 1–1.3 mm long; anthers 6.6–10.7 mm long, 1.5–2.4 mm wide, lanceolate, sagittate at base, narrowed towards the apex, dehiscing by apical pores, connivent. Ovary short-cylindrical, convex at the apex, with some glandular trichomes; style of long styled flowers 13.6–14.3 mm long, white, cylindrical, often gently curved distally, stellate-tomentose at base, in short-styled flowers the style 7.4–9 mm long, straight; stigma 1–1.3 mm long, often bilobed at the apex, green, the surface papillose. Fruit a broadly depressed ovate to spherical berry, 9.7–13 mm long, 12.3–14.5 mm wide, the pericarp smooth, glabrous, the exposed portion white and the portion covered by the calyx green to pale green at maturity; fruiting pedicels 2–2.4 cm long, unarmed; fruiting calyx accrescent, completely covering the earlier stages of development of the fruit and ½–¾ of the mature fruit, the base rounded, the lobes 3.5–10 mm long, 5.6–8 mm wide at the base. Seeds ca. 40–50 per berry, 3.5–4.5 mm long, 3.1–3.4 mm wide, flattened, reniform, stramineous to pale brown. Chromosome number: not known. Figures 3 , 12 .

Habitat and Distribution — Solanum igniferum is endemic to southern Esp´ırito Santo State, Brazil ( Fig. 9 ). It grows in damp soil with indirect light, at the edge and in openings of wet forest fragments, these sometimes associated with granitic outcrops; from 400 to 980 m elevation.

Phenology —Flowering plants have been collected between November and June, with the flowering peak from December to April; fruiting plants have been collected from February to June.

Preliminary Conservation Status —The conservation status of S. igniferum is considered endangered (EN) based on the small extent of occurrence (EOO, 145 km 2), the very small area of occurrence (AOO, 20 km 2) and the fact that there is no record of this species from within protected areas ( IUCN 2016).

Etymology —The specific epithet “ igniferum ʺ refers to its distinctive fire-colored indumentum.

Additional Specimens Examined — Brazil. — ESPÍRITO SANTO: Mun. Alfredo Chaves, S~ ao Bento de Urania ˆ, 900 m, 14 Jan 1995 (fl), Hatschbach & Silva 61483 ( CEPEC, MBM, NY); Mun. At´ılio Vivacqua, estrada de terra para a comunidade de Moitao~ do Sul, 21°00, 11 ̎ ʺS, 41°12, 15 ̎ ʺW, 461 m, May 2015, Gouvea ˆ& Falcao~ 190 ( BHCB); 21°00, 08 ̎ ʺS, 41°12, 15 ̎ ʺW, 435 m, 05 June 2012 (fl, fr), L.L. Giacomin et al. 1845 ( BHCB, NY, RB); Mun. Marechal Floriano, Pedra Azul, 16 May 1999 (fl), Hatschbach et al. 69092 ( BHCB, C, MBM). Locality not indicated: Sellow s.n., (BR, [BR0000008366290]).

Notes — Solanum igniferum is unique in the S. asterophorum species group due to the notable orange to ferruginous indumentum of its adaxial leaf surfaces, midrib of both leaf sides, calyces, pedicels, inflorescence axis, and young stems, its plagiotropic branches sprawling horizontally, and the straight or nearly straight pedicels with erect to horizontally oriented buds (see Fig. 3 ). Solanum igniferum resembles S. asterophorum , but the indumentum of S. asterophorum is hyaline, yellowish or somewhat brown, the branches are erect and the pedicels curved downward with the buds pointing downwards. Solanum igniferum also resembles S. piluliferum in its somewhat similar colored indumentum, but the cupuliform calyx and entire leaves of S. piluliferum readily distinguish it from S. igniferum .

The first specimen corresponding to S. igniferum was collected by Sellow s. n. (BR [BR0000008366290]) with no locality indicated and determined as S. asterophorum . This material was suggested to be a syntype de S. asterophorum var. tomentosum by Nee, but no evidence exists to recognize it as such (see comments under S. asterophorum ).

Figures

FIG. 3. Photo of type collection of Solanum igniferum (Y.F. Gouvˆea & J.R. Stehmann 164, BHCB). A. Habit; note the orange indumentum completely covering the stems, the forked branching typical of the group, and the plagiotropic branches unique to S. igniferum. B. Young inflorescence; note the pedicels straight or nearly so, with the buds erect to horizontally oriented. C. Mature inflorescence. D. Fruits.

FIG. 12. Scan of holotype of Solanum igniferum (Y.F. Gouvˆea & J.R. Stehmann 164, BHCB [BHCB026909], sheet one).

FIG. 9. Distribution of Solanum igniferum.