Solanum lyratum
Citation:
Fl. Jap. 92. 1784.
Last edited by:
Sandra Knapp (May 2014)
Written by:
Sandra Knapp
Habit:
Sprawling shrub or herbaceous vine, woody at the base. Stems flexuous, not winged, sparsely to densely pubescent with translucent, glandular, simple uniseriate trichomes to 4 mm long, with 4-6 cells, the gland 1-celled, these overtopping shorter glandular simple trichomes ca. 0.5 mm long, the trichomes weak and tangled; new growth densely pubescent with trichomes like those of the stems. Bark of older stems pale yellowish tan, glabrescent, the longer trichomes usually breaking off and only the shorter ones remaining.
Sympodial structure:
Sympodial units plurifoliate.
Leaves:
Leaves simple or pinnatifid, usually only with 2 lyrate lobes at the base, 2-6(-9) cm long, 0.5-5(-7) cm wide, cordate to lyrate, widest in the basal third, thin and membranous, both surfaces uniformly pubescent with weak, translucent simple uniseriate trichomes to 4 mm long, these usually glandular like those of the stems; primary veins 5-7 pairs, usually yellowish in dry material; base cordate, occasionally truncate, not decurrent on the petiole; margins entire or lobed, the lobes usually only a pair at the base, these sometimes completely divided and the leaf apparently pinnate, occasionally with up to 4 pairs of lobes; apex acuminate or acute; petiole 1-3 cm long, pubescent like the stems, twining.
Inflorescences:
Inflorescences terminal or lateral, 2.5-10 cm long, open and many times branched, with 10-40+ flowers, usually only a few open at a time, pubescent with simple uniseriate glandular trichomes like those of the stems; peduncle 2-6 cm long; pedicels 7-11 mm long, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter at the apex, slender and spreading, glabrous or short-glandular pubescent, articulated at the base in a small sleeve 1-2 mm long; pedicel scars irregularly spaced 2-9 mm apart, more congested distally. Buds ellipsoid, the corolla strongly exserted from the calyx tube before anthesis.
Flowers:
Flowers all perfect, 5-merous. Calyx tube 1-1.5 mm long, conical, the lobes 0-1 mm long, deltate or mere enations on the calyx rim, glabrous, papillate on the tips. Corolla 8-13 mm in diameter, white to pale lavender, with green and white spots at the base of each lobe, stellate, lobed ¾ of the way to the base, the lobes 3-6 mm long, 2-3 mm wide, strongly reflexed at anthesis, the tips and margins densely papillose. Filament tube minute, the free portion of the filaments 1-1.5 mm long, glabrous; anthers 3-3.5 mm long, 1-1.5 mm wide, ellipsoid, loosely connivent, often dark blue or black, the base sagittate, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 5-7 mm long, glabrous; stigma capitate, the surface minutely papillate.
Fruits:
Fruit a globose berry, ca. 1 cm in diameter, bright red, translucent and shiny when ripe, the juice staining scarlet; fruiting pedicels 1-1.5 cm long, ca. 0.75 mm in diameter at the base, spreading.
Seeds:
Seeds >30 per berry, ca. 2.5 mm long, ca. 1.5 mm wide, flattened reniform, pale yellowish tan, the surfaces minutely pitted, when mature the seed apparently hairy from the elongate lateral testal cell walls, these to 0.5 mm.
Chromosome number:
Not known.
Distribution:
Solanum lyratum occurs in a wide variety of habitats in China, Japan and north Vietnam, from sea level to 1500 m. Usually growing in secondary situations along roadsides and in waste ground; often in urban areas.
Phylogeny:
Solanum lyratum is a member of the Dulcamaroid clade (Knapp 2013) and is probably related to other Old World members of the group.
References:
For references cited here please see Knapp, S. 2013. A revision of the Dulcamaroid Clade of Solanum L. (Solanaceae). PhytoKeys 22: 1-432.
Common names and uses:
China: bai ying (Zhang et al. 1994); Japan: murasaki-hiyodorijogo (Konta et al. 2007).
Conservation status:
Least Concern (LC); EOO >100,000 km2 (LC) and AOO >10,000 km2 (LC). See Moat (2007) for explanation of measurements.
Like the other temperate zone species in the Dulcamaroid clade (S. dulcamara, S. pittosporifolium), S. lyratum is widely distributed, somewhat weedy and grows in many different habitats. It is sympatric with and very similar to S. pittosporifolium; the species can be differentiated by leaf pubescence. Solanum lyratum always has long glandular trichomes on all vegetative parts, especially the new growth, while S. pittosporifolium is glabrous or has very short uniseriate trichomes on the leaves and young stems. Leaf shape in S. lyratum is extremely variable; most specimens have lyrate leaf bases and ternate leaves with a very large central lobe (see Figure 2 in Knapp 2013), but simple leaves are common and some specimens (e.g., Licent 2286, the type of S. septemlobum var. indutum) have pinnatifid leaves with 5-7 pairs of leaflets. Pubescence, however, is very consistent and is an excellent diagnostic character for S. lyratum. Flower color also varies from dark purple to white, but there are always green spots at the base of the corolla lobes. Although most Solanum species have bright yellow anthers, S. lyratum occasionally has blackish purple anthers; it is not clear whether this is genetic or is due to an environmental effect. Anthers in S. lyratum are never tapered like those of S. dulcamara; due to pubescence differences these two species are not difficult to distinguish (but see S. pittosporifolium).
Two specimens at “herb. Banks” (Macartney s.n. and Staunton s.n. both now at BM) were cited by Dunal in his description of S. dulcamara var. chinense. The Macartney collection (BM000942424) has here been selected as the lectotype in order to preserve usage, as it is a specimen of S. lyratum; the Staunton sheet (BM000942515) is S. septemlobum.