Solanum sarrachoides
Citation:
Fl. Bras. (Martius) 10: 18, tab. 1, fig. 1-8. 1846
Type:
BRAZIL. “Brasilia australis”, F. Sellow s.n. (lectotype, designated by Edmonds 1986, pg. 16: P [P00371162]).
Last edited by:
Sandra Knapp
Written by:
Tiina Särkinen, Peter Poczai, Gloria E. Barboza, Gerard M. van der Werden, Maria Baden and Sandra Knapp
Habit:
Annual erect to decumbent herbs 30-70 cm tall, rarely to 1 m, somewhat branching at base. Stems sprawling, terete, green, not markedly hollow; new growth densely viscid-pubescent with simple, spreading, uniseriate, translucent, glandular trichomes, the trichomes of two lengths, the shorter 1-4-celled, 0.2-0.5 mm long and the longer 5-14-celled, 1-2 mm long, both with glandular apical cells; older stems glabrescent.
Sympodial structure:
Sympodial units difoliate, the leaves not geminate.
Leaves:
Leaves simple, 3.0-7.5 cm long, 3.0-6.0 cm wide, broadly ovate, thin membraneous, concolorous, without smell; adaxial and abaxial surfaces sparsely to densely pubescent with spreading, simple, uniseriate glandular trichomes like those of the stem, evenly distributed on lamina and veins; major veins 3-4 pairs; base truncate to cordate, sometimes asymmetric; margins entire or regularly sinuate-dentate; apex acute; petioles 0.5-3.2 cm long, sparsely pubescent with trichomes like those of the stem and leaves.
Inflorescences:
Inflorescences 0.7-1.7 cm long, usually leaf-opposed but occasionally internodal, simple, subumbelliform, with 2-5(6-7) flowers clustered at the tip, sparsely pubescent with spreading trichomes like those of the stems; peduncle 0.7-1.0 cm long, straight; pedicels 5-7 mm long, 0.1-0.2 mm in diameter at the base, 0.3-0.4 mm in diameter at the apex, straight and spreading, articulated at the base; pedicel scars spaced ca. 0(-1) mm apart. Buds globose, the corolla included within the calyx lobes and only the tip of the bud showing.
Flowers:
Flowers 5-merous, all perfect. Calyx tube 0.5-1.0 mm long, conical, the lobes 1.5-2.0 mm long, 0.5-0.7 mm wide, lanceolate to narrowly ovate with acute apices, sparsely pubescent with 1-4-celled spreading glandular trichomes like those on the pedicels but shorter. Corolla 5-8 mm in diameter, white with a yellow-green central eye, pentagonal-stellate, lobed 1/2-1/3 of the way to the base, the lobes 3.0-4.5 mm long, 5.0-7.0 mm wide, spreading at anthesis, sparsely papillate-pubescent abaxially with glandular 1-4-celled simple uniseriate trichomes and eglandular papillae, the denser along margins, tips and midvein. Stamens equal; filament tube minute; free portion of the filaments 1.0-1.5 mm long, adaxially sparsely pubescent with tangled uniseriate 4-6-celled simple trichomes; anthers 1.2-2.0 mm long, 0.4-0.8 mm wide, ellipsoid, yellow, poricidal at the tips, the pores lengthening to slits with age and drying. Ovary globose, glabrous; style 3.0-3.5 mm long, densely pubescent with 2-3-celled simple uniseriate trichomes in the lower 1/2- 2/3 where included in the anther cone, not usually exserted beyond the anther cone; stigma capitate, minutely papillate, green in live plants.
Fruits:
Fruit a globose berry, 6-9 mm in diameter, green-brownish grey at maturity, the pericarp thin and matte to somewhat shiny; fruiting pedicels 5-9 mm long, 0.2-0.3 mm in diameter at the base and at the apex, spaced 0-1 mm apart, reflexed, dropping with mature fruits, not persistent; fruiting calyx accrescent, becoming papery in mature fruit, the tube 3-4 mm long, the lobes 5.5-8.0 mm long and 3.5-4.0 mm wide, the tips slightly reflexed or spreading.
Seeds:
Seeds (23-)59-69(-93) per berry, 1.3-1.7 mm long, 1.0-1.5 mm wide, flattened and tear-drop shaped with a subapical hilum, pale yellow, the surfaces minutely pitted, the testal cells pentagonal in outline. Stone cells 4-6 per berry, (0.5) 0.8-1 mm in diameter.
Chromosome number:
2n=2x=24 (Edmonds 1972, 1977; Bukenya 1996; Moyetta et al. 2013; Olet et al. 2015).
Distribution:
Solanum sarrachoides is native to southern South America, but has been introduced globally as an agricultural weed. It grows in urban areas, along riversides, and other disturbed areas; between 0 - 2,300 m elevation in its native range, between 0 - 800 (1,400) m in the introduced range.
References:
Common names and uses:
Old World: South Africa: umrobe wezinja; Sweden: Klibbnattskatta (Mossberg et al. 2003); United Kingdom: leafy-fruited nightshade (Stace 2010).
Conservation status:
Preliminary conservation status (IUCN 2016). Solanum sarrachoides is not a weedy species and has not spread far despite various introductions across the world; in its native range it is widespread (EOO 2,089,288 km2) and can be assigned a preliminary status of LC (Least Concern; Table 7 in Sarkinen et al. 2018).
Solanum sarrachoides is morphologically similar to S. nitidibaccatum. The two taxa can be distinguished based on generally truncate leaf bases, leaf-opposed inflorescences that are umbellate to sub-umbellate with fewer flowers (2-5, rarely 6-7), shorter calyx lobes 1.5-2.0 mm long, and a corolla with yellow-green central eye in S. sarrachoides, compared to S. nitidibaccatum which has attenuate to cuneate leaf bases, internodal inflorescences that are racemose with more flowers (4-8, occasionally up to 9-10), longer calyx lobes 1.7-2.5 mm long, and a corolla with yellow-green central eye with black-purple V- or U-shaped margins. The buds of S. sarrachoides are included in the calyx until just before anthesis and the berries are usually matte instead of shiny as they are in S. nitidibaccatum.
Solanum sarrachoides is a diploid species native to north-eastern and central Argentina, Paraguay and southernmost Brazil. The introduction of the species to Europe and North America is largely due to trade with South America and the importation of seeds and grain together with the practice of spreading wool waste (‘shoddy’) as manure, and based on herbarium records seems to have been introduced some time at the beginning of the 20th century. Despite its introduction in the early 1900s, the species remains relatively uncommon in both Europe and North America, with sporadic records from elsewhere, including South Africa (e.g., Eastern Cape, Phillipson & Hobson 5256). Solanum sarrachoides has not spread to Australasia; all literature records (e.g., Healy 1974; Henderson 1974; Ogg et al. 1981; Schilling 1981; Symon 1981) suggest that material from Australasia refers to material we recognise as S. nitidibaccatum.
Within the Old World, S. sarrachoides has often been confused with S. nitidibaccatum and records of S. sarrachoides or S. nitidibaccatum in the literature should be taken with caution due to common misidentification of voucher material. Many regional treatments do not separate between these morphologically very similar species (e.g., Stebbins and Paddock 1949).
Edmonds (1986) provides a discussion of the complex synonymy and lectotypification of S. sarrachoides. The species epithet is often seen spelled as “sarachoides”, because Sendtner was thought to have named this species after the genus Saracha Ruiz & Pav. (after the taxa now part of the genus Jaltomata Schltdl.), but in Flora Brasiliensis (Sendtner 1846) he used both “Saracha” and “Sarracha”, and Edmonds (1986) determined that the name is correctly spelled S. sarrachoides following the original publication.