Solanum praetermissum Kerr ex Barnett, Kew Bull. 16: 485. 1963.

Aubriot, Xavier & Knapp, Sandra, 2022, A revision of the " spiny solanums " of Tropical Asia (Solanum, the Leptostemonum Clade, Solanaceae), PhytoKeys 198, pp. 1-270 : 1

32. Solanum praetermissum Kerr ex Barnett, Kew Bull. 16: 485. 1963.

Figs 4G , 53

Solanum barbisetum Nees var. griffithii Prain, J. Asiat. Soc. Beng. 65(2): 541. 1896. Type. India. [Arunachal Pradesh?]: "Upper Assam", 1841, F. Jenkins 253 (lectotype, designated by Hul and Dy Phon 2014, pg. 36: K [K000449043]; isolectotype: K [K000449042]).

Solanum griffithii (Prain) C.Y.Wu & S.C.Huang, Acta Phytotax. Sin. 16(2): 75. 1978, non S. griffithii (C.B.Clarke) Kuntze, 1891. Type. Later homonym, based on Solanum barbisetum Nees var. griffithii Prain.

Solanum neogriffithii V.V.Hop, J. Biol. Vietnam 27(3): 13. 2005. Type. Based on Solanum barbisetum Nees var. griffithii Prain.

Solanum membranisepalum Li Bing Zhang & Ngan T.Lu, Phytotaxa 186(4): 239. 2014. Type. Based on Solanum barbisetum Nees var. griffithii Prain.

Solanum brevipedunculatum Li Bing Zhang & Yi F.Duan, Phytotaxa 170(4): 280. 2014, non S. brevipedunculatum Rusby, 1907. Type. Based on Solanum barbisetum Nees var. griffithii Prain.

Type.

Thailand. Tak: Raheng [Rahaeng], E. Smith s.n. (holotype: K [K000614048]; isotypes: BK [ BK229395 ], BM [BM000886099]) .

Description.

Herbs to small shrubs, to 0.5 m tall, armed. Stems erect, terete, moderately to sparsely prickly and densely stellate-pubescent; prickles to 4 mm long, to 2 mm at the base, straight, narrowly deltate, pale yellow, glabrous; trichomes porrect-stellate, mixture of sessile and stalked, the stalks to 0.25 mm long, the rays 4-8, 0.1-0.4 mm long, the midpoints up to 0.1 mm long; new growth densely stellate-pubescent, whitish green in dry material; bark of older stems light brownish, moderately to densely stellate pubescent. Sympodial units difoliate, the leaves geminate, the leaves of a pair differing somewhat in size but not in shape. Leaves simple, entire to shallowly lobed, the blades 9-17 cm long, 6.5-13 cm wide, ca. 1-1.5 times longer than wide, ovate to broadly ovate, chartaceous, discolorous, moderately prickly with 4-16(-24) prickles per leaf side, usually longer than those of the stems, up to 7 mm long, often purplish black in living plants; adaxial surface dark green, moderately to densely stellate-pubescent, the stellate trichomes porrect, sessile or stalked, the stalks to 0.1 mm long, the rays 4-7, 0.1-0.4 mm long, the midpoints up to 0.5 mm long; abaxial surface light green, densely stellate-pubescent with trichomes like those of the adaxial surface but more long-stalked; major veins 4-5 pairs drying whitish brown; base attenuate to truncate; margins sinuate to shallowly lobed, the lobes 3-4 on each side, 0.5-2 cm long, broadly deltate to obovate, apically rounded to acute, the sinuses extending up to 1/3 of the distance to the midvein; apex acute; petiole 2.5-7 cm long, 1/4-1/3 of the leaf blade length, densely stellate-pubescent with porrect sessile trichomes like those of the stems, unarmed or with 1-8 prickles like those of the blades. Inflorescences 1.5-3 cm long, apparently lateral, unbranched, with ca. 5-11 flowers, 1-2 flowers open at any one time; axes densely stellate-pubescent with trichomes like those of the stems, but sometimes purplish tinged in living plants, unarmed or with prickles like those of the stems but smaller, often purplish black in live plants; peduncle 0.2-1 cm long, with 0-4 prickles; pedicels 0.4-1 cm long, ca. 0.75 mm in diameter at the base, ca. 1.5 mm in diameter at the apex, erect to recurved, unarmed or with 1-2 small prickles, densely stellate-pubescent with trichomes like those of the inflorescence axes, articulated at the base; pedicel scars spaced 1-3 mm apart. Buds oval to ellipsoid, more or less exserted from the calyx before anthesis. Flowers 5-merous, apparently all perfect. Calyx with the tube 2-3 mm long, conical, the lobes 2-3.5 mm long, 0.75-1.5 mm wide, narrowly deltate, apically acute, unarmed and densely stellate-pubescent abaxially with trichomes like those of the pedicels. Corolla 0.7-1.5 cm in diameter, white, sometimes pale lilac, stellate, lobed ca. 2/3 of the way to the base, the lobes 4-5.5 mm long, 1.5-3 mm wide, narrowly deltate to deltate, spreading at anthesis, glabrous adaxially, densely stellate pubescent abaxially on parts exposed in bud. Stamens equal; anthers 4-5 mm long, ca. 1 mm wide, not markedly connivent, tapering, yellow, glabrous, poricidal at the tips, the pores directed distally, not elongating to slits with drying; filament tube <1 mm long; free portion of the filaments 0.5-1 mm long, glabrous. Ovary conical, minutely glandular-puberulent at the top; style ca. 6 mm long, slender, slightly recurved at the apex, glabrous; stigma capitate, minutely papillate. Fruit a globose berry, 4-8 per infructescence, 0.8-1.2 cm in diameter, whitish cream at maturity, the pericarp smooth, glabrous; fruiting pedicels 0.9-1.2 cm long, ca. 1 mm in diameter at the base, 2-3.5 mm in diameter at the apex, woody, erect to recurved, unarmed or with 1-10 prickles; fruiting calyx accrescent, completely covering the fruit at maturity, the tube enclosing the ripe berry, prickly and stellate-pubescent, the lobes expanding to 1 cm long, with up to 20 prickles per lobe, these often purplish black in living plants. Seeds 20-50 per berry, 2-3 mm long, 1.5-2 mm wide, flattened-reniform, light brownish, the surface minutely pitted, the testal cells somewhat sinuate in outline. Chromosome number: not known.

Distribution

(Fig. 54 ). Solanum praetermissum occurs from northeastern India to South China and Vietnam.

Ecology and habitat.

Solanum praetermissum is a plant of evergreen broadleaf forests or semi-deciduous forests, growing in forest understory or in clearings of secondary woodlands, or on rocky banks; from 300 to 400 m elevation.

Common names and uses.

Vietnam. co chu (Muong, Hul and Dy Phon 2014).

Preliminary conservation status

( IUCN 2019). Least Concern (LC). EOO (1,191,003 km2, LC); AOO (68 km2, EN). Solanum praetermissum is widely distributed, but where we have seen it in the field, is in small populations, perhaps indicating further assessment is necessary.

Discussion.

Solanum praetermissum is most similar to S. barbisetum , with which it is sympatric and has previously been confused. It was first described as a variety of the latter (as var. Solanum barbisetum griffithii ) and once it was recognised as distinct several attempts were made to assign a name at the specific level (see synonymy); none of these authors apparently realised the name S. praetermissum was already published and thus had priority. Both species are small shrubs and have small, whitish cream berries enclosed in prickly accrescent calyces. Solanum praetermissum can be distinguished from S. barbisetum in its pubescence of largely sessile stellate trichomes (versus long-stalked stellate trichomes), lack of bristles on the inflorescence (versus densely bristly inflorescences and calyces, especially in fruit), generally shorter inflorescence axes (1.5-3 cm versus 3-10 cm long, although some young inflorescences can be shorter), and smaller flowers (0.7-1.5 cm versus 1.8-2.2 cm in diameter).

Mill (2001) treated S. praetermissum for Bhutan under the synonym S. griffithii , with the suggestion that they were doubtfully distinct. He cited no specimens for Bhutan for either species.

Aubriot et al. (2016a) resolved S. praetermissum as sister to the southern Indian endemic S. wightii , but with very low support; in the same study, S. barbisetum was resolved as sister to the ' S. expedunculatum and relatives’ lineage albeit with poor support. Solanum wightii also has a strongly accrescent calyx but is otherwise morphologically very different from S. praetermissum (see description below).

Specimens examined.

See Suppl. materials 1-3.

Figures

Figure 4. Diversity of fruits and seeds in tropical Asian spiny solanums A large oval fruit of Solanum insanum (Sampath Kumar et al. 126918, India) B condensed infructescence and small rounded fruits of Solanum hovei (field photograph, unvouchered, India) C large rounded hairy fruit of S. involucratum with strongly accrescent and spiny calyx (field photograph, unvouchered, Vietnam) D small rounded fruit of Solanum pubescens with elongated calyx lobes (Sampath Kumar et al. 126956, India) E rounded fruit of Solanum cyanocarphium with strongly accrescent and spiny calyx (field photograph, unvouchered, Vietnam) F small rounded fruit of S. trilobatum in transverse cut (Meeboonya et al. RM 242, Thailand) G rounded fruit and accrescent calyx of S. praetermissum in transverse cut (field photograph, unvouchered, Vietnam) H oval fruit of Solanum virginianum in transverse cut (field photograph, unvouchered, India). Photograph credits: A, B, D, F, H X. Aubriot C, E, G M. Nuraliev.

Figure 53. Solanum praetermissimum Kerr ex Barnett A herbarium specimen collected in Laos in 1974 (Vidal 5855, P 00074767) B habit (field photograph, unvouchered, Vietnam) C detail view of a fruit with the calyx removed (field photograph, unvouchered, Vietnam) D detail view a flower (field photograph, unvouchered, Vietnam) E detail view an infructescence (field photograph, unvouchered, Vietnam). Photograph credits: A CC-BY, Museum national d'Histoire naturelle, Paris B-E M. Nuraliev.

Figure 54. Distribution of S. praetermissum.