A revision of the " spiny solanums " of Tropical Asia (Solanum, the Leptostemonum Clade, Solanaceae)
Author
Aubriot, Xavier
Universite Paris-Saclay, CNRS, AgroParisTech, Ecologie Systematique et Evolution, 91190, Gif-sur-Yvette, France & The Natural History Museum, Cromwell Road, London SW 7 5 BD, UK
Author
Knapp, Sandra
https://orcid.org/0000-0001-7698-3945
The Natural History Museum, Cromwell Road, London SW 7 5 BD, UK
s.knapp@nhm.ac.uk
text
PhytoKeys
2022
2022-06-01
198
1
270
http://dx.doi.org/10.3897/phytokeys.198.79514
journal article
http://dx.doi.org/10.3897/phytokeys.198.79514
1314-2003-198-1
486F1F1B4F5854D2831AAA341B9A322C
35.
Solanum pubescens Willd., Phytographia 1: 5. 1794.
Figs 3D
, 4D
, 59
Solanum calycinum
Nees, Trans. Linn. Soc. London 17(1): 60. 1834. Type. India. Sin. loc., "Herb. Madr. 237",
Anonymous s.n.
[Wallich Catal. Suppl. n. 237] (lectotype, designated here: GZU [GZU000255511])
Solanum neesianum
D.Dietr., Syn. Pl. (D. Dietrich) 1: 697. 1839, nom. illeg., non
Solanum neesianum
Wall. ex Nees, 1834. Type. Based on
Solanum calycinum
Nees
Solanum esenbeckii
Steud., Nomencl. Bot. ed. 2, 2: 602. 1841, nom. illeg. superfl. Type. Based on
Solanum calycinum
Nees
Solanum conanthum
Dunal, Prodr. [A. P. de Candolle] 13(1): 127. 1852, nom. illeg. superfl. Type. Based on
Solanum calycinum
Nees
Type
.
Cultivated. "
Habitat in Indiae
hortis, arboretis solo argilloso rarius",
Anonymous s.n.
(
lectotype
, designated by
Hepper 1987
, pg. 369, as
"type"
: B [B-W04313-010])
.
Description.
Erect shrubs to 5 m tall, unarmed. Stems erect, terete, stellate-pubescent and sticky glandular; pubescence of very short-stalked multangulate trichomes mixed with sessile porrect-stellate trichomes, the multangulate trichomes with more than 10 rays, the rays 0.4-0.5 mm long, the porrect-stellate trichomes with 6-8 rays, 0.4-0.5 mm long, the midpoints to 1 mm long, all trichomes usually glandular tipped and the plants sticky; new growth densely glandular-pubescent, the trichomes tangled, soon deciduous and the stems glabrate; bark of older stems greyish white. Sympodial units plurifoliate, the leaves not geminate. Leaves simple, unlobed, the blades 2.5-12 cm long, 1.5-7 cm wide, ca. 1-1.5 times longer than wide, ovate to broadly triangular, widest in the lower third, chartaceous, more or less concolorous, unarmed, the leaves of lower stems much larger than those of distal branches; adaxial surface evenly and densely pubescent with sessile and very short-stalked porrect-stellate trichomes, the rays 4-8, to 0.5 mm long, glandular at the tips, the midpoints 2-4-celled, to 2 mm long, glandular at the tips; abaxial surface with similar porrect-stellate trichomes, but these denser especially along the veins; major veins 3-4 pairs, densely pubescent especially abaxially; base abruptly truncate to cordate, somewhat oblique; margins entire or slightly sinuate, not lobed; apex acute; petioles 1-4 cm long, 1/2 of the leaf blade length, unarmed, more densely glandular stellate-pubescent than the stems, but the trichomes of the same morphology. Inflorescences to 3 cm long, internodal and lateral, unbranched, with 5-12 flowers, only 1 or 2 flowers open at any one time, densely glandular pubescent with mixed multangulate and stellate-porrect trichomes like those of the stems; peduncle 0.3-0.5 cm long; pedicels 1.2-1.6 cm long, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter at the apex, spreading at anthesis, glandular stellate-pubescent like the inflorescence axes, articulated at the base; pedicel scars irregularly spaced 1-3 mm apart. Buds elongate ellipsoid and tapering, strongly exserted from the calyx before anthesis. Flowers 5-merous, apparently all perfect. Calyx with the tube 2-2.5 mm long, conical, the lobes 3.5-5 mm long, ca. 1.5 mm wide, long-triangular to lanceolate, apically acute, densely stellate-pubescent abaxially with mixed glandular multangulate and porrect-stellate trichomes like those of the pedicels. Corolla 2-2.2 cm in diameter, violet or deep purple, stellate, lobed 3/4 of the way to the base, minimal interpetalar tissue present, the lobes 6-7 mm long, 4-4.5 mm wide, spreading at anthesis, mostly glabrous adaxially or with a few stellate trichomes along the petal midvein, densely stellate-pubescent abaxially with densely tangled sessile trichomes where exposed in bud, these densest at the tips. Stamens markedly unequal, with 4 short and one long and curved; long anther 7.5-9 mm long, 1-1.5 mm wide, strongly curved and tapering, short anthers 5-7 mm long, 1-1.5 mm wide, straight, all anthers yellow, glabrous, poricidal at the tips, the pores directed distally, not elongating to slits with drying; filament tube minute, glabrous; free portion of the filaments ca. 0.5 mm long, glabrous. Ovary conical, glabrous; style 9-10 mm long, strongly curved inwards and held adjacent to the long anther, glabrous; stigma capitate or slightly clavate, the surfaces minutely papillose. Fruit a globose berry, several per infructescence, 1-1.6 cm in diameter, orange-red when ripe, the pericarp thin and shiny, glabrous; fruiting pedicels 2.5-3.5 cm long, ca. 1.5 mm in diameter at the base, 2-2.5 mm in diameter at the apex, somewhat woody, spreading to pendent from weight of berries; fruiting calyx not accrescent, the lobes often breaking off. Seeds 20-30 per berry, 4-5 mm long, 3.5-4 mm wide, flattened reniform, yellowish or reddish brown, the surfaces minutely pitted, the testal cells with sinuate margins. Chromosome number: 2n = 24 (
Chennaveeraiah and Krishnappa 1971
;
Rao and Rao 1987
).
Figure 59.
Solanum pubescens
Willd.
A
herbarium specimen collected in India (
Wight 2629b
, BM000900098)
B
habit (
Sampath Kumar et al. 126956
, India)
C
inflorescence (
Sampath Kumar et al. 126956
, India)
D
immature fruit (
Sampath Kumar et al. 126956
, India). Photograph credits:
A
CC-BY, © copyright The Trustees of the Natural History Museum, London
B-D
X. Aubriot.
Distribution
(Fig.
60
).
Solanum pubescens
occurs from India to Saudi Arabia and Yemen on the Arabian Peninsula.
Ecology and habitat.
Solanum pubescens
is found in a variety of dry forest types, such as thorn forest, often occurring in open areas and along roadsides, from 300 to 1,000 m elevation.
Common names and uses.
India. sonde, hucchu sonde, savadangi, cherichunda (Malayam), kaattu sundai kaai (Tamil), usthi kaai (Telugu) (https://www.flowersofindia.net). It is recorded as being used for bowel and joint pains (see https://www.flowersofindia.net).
Preliminary conservation status
(
IUCN 2019
).
Least Concern (LC). EOO (996,977 km2, LC); AOO (272 km2, EN). Like many other spiny solanums in tropical Asia,
S. pubescens
is widely distributed in a variety of habitats, although the AOO suggests some concern, this is a common species.
Figure 60.
Distribution of
S. pubescens
.
Discussion.
Solanum pubescens
is morphologically similar and probably closely related to
S. vagum
, sharing with that species zygomorphic flowers at anthesis, heteromorphic anthers and shiny berries on erect or slightly pendulous pedicels.
Hepper (1987)
treated material of
S. vagum
from Sri Lanka as
S. pubescens
in the "Revised Handbook to the Flora of Ceylon".
Solanum pubescens
differs from
S. vagum
in its glandular pubescence, its narrowly elliptic leaves with attenuate bases and slightly smaller, violet (rather than white) flowers. In
S. pubescens
the lamina of young leaves is obscured by the dense covering of glandular stellate to multangulate stalked trichomes with elongate midpoints and the leaves are described as "oily to touch" (
Singh 1988
), while in
S. vagum
the pubescence of adaxial leaf surfaces is of very sparse sessile stellate trichomes with midpoints usually equal to the rays, and the lamina is clearly visible. The two species are sympatric in southern India.
Solanum pubescens
and
S. vagum
share a zygomorphic androecium, with one anther distinctly longer than the rest. From herbarium sheets it appears that this difference becomes more pronounced with flower age. Post-anthesis anther expansion occurs in the unrelated
S. turneroides
Chodat (Brevantherum clade, see
Stern et al. 2013
) of southern South America. Buds of the African species
S. somalense
Franch. also have the anthers of more or less equal length that become different with age (
Vorontsova and Knapp 2016
). This phenomenon needs study with populations in the field and lab.
The
Solanaceae
from Nees van
Esenbeck's
personal herbarium are held in Graz at GZU (
Stafleu and Cowan 1981
). The sheet in GZU is the only one we have found of the Wallich Herb.
"Madras"
gatherings cited in the protologue of
S. calycinum
. We therefore designate it (GZU000255511) as the lectotype of
S. calycinum
.
Dunal (1852)
coined the replacement name
S. conanthum
for
S. calycinum
Nees citing "non Dunal" in reference to his own
S. calycinum
(=
S. macrocarpon
L. of Africa, the Gboma eggplant, see
Vorontsova and Knapp 2016
) that is a later homonym of Nees van
Esenbeck's
name.
Specimens examined.
See Suppl. materials 1-3.