Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum ×edinense

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Citation author: 
P. Berthault
Citation: 
Rech. bot. Solanum tub. 142, fig. 41, 42, tab. 8. 1911.
Type: 
Mexico. Tlaxcala: below Pilares, Mount Malinche (from Huamantla), 8500 ft, 17 Oct 1938, N. Balls, E. K. Balls, & W. B. Gourlay 5658 (neotype, designated by Spooner et al., 2004: K!).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M.
Habit: 
Herbaceous tuber-bearing perennials 1-2 m tall. Stems 3-6 mm in diameter at base of plant.
Sympodial structure: 
Sympodial units typically 3-6-foliate.
Leaves: 
Pseudostipules 5-10 mm long, lunate. Leaves odd-pinnate, 10-21 cm long, 6-12 cm wide, puberulent to pubescent adaxially and abaxially; petioles 1-3 cm long; lateral leaflet pairs 3-5, the size of the lateral leaflets diminishing gradually towards the base of the leaf; most distal lateral leaflets 3.5-7 cm long, 2-3.5 cm wide, ovate to broadly elliptic to obovate, apex acute to acuminate, base oblique, cuneate top truncate, sometimes with interjected leaflets on the petiolules; terminal leaflet 4.5-8.5 cm long, 2-3.5 cm wide, broadly elliptical to obovate, apex acute to acuminate, base cuneate, frequently with interjected leaflets on the petiolule; interjected leaflets 5-15.
Inflorescences: 
Inflorescence a dichasially branched, ebracteate, monochasial or dichasial cyme, 2-3 forked, generally in the distal half of the plant, with 8-12 flowers, all flowers perfect, peduncle 4-10 cm long; pedicels 20-35 mm long, articulate between the proximal ¼ and the distal ¼.
Flowers: 
Flowers with the calyx 5-8 mm long, lobes acute to long-attenuate, acumens 2-3 mm long. Corollas 2.8-3.2 cm in diameter, rotate, acumens 3-4 mm long, edges of corolla flat, not folded dorsally, white to dark violet above and below. Anthers 6-8 mm long, connate, yellow, apically poricidally dehiscent and often maturing to a short introrse apical slit, filaments 1-4 mm long. Ovary with style 8-9 mm long, exceeding stamens by 1-3 mm, straight, with stigma globose.
Fruits: 
Fruits 1-2 cm in diameter, globose, medium green throughout.
Seeds: 
Seeds generally not present, but the rare seeds produced are green-white throughout, ovoid, ca. 2 mm long, with a thick covering of “hair-like” lateral walls of the testal cells that make the seeds mucilaginous when wet. Removal of these hair-like lateral walls by enzyme digestion reveals a honeycomb pattern at their base.
Chromosome number: 

2n = ploidy missing =60 voucher missing = (Spooner & Hijmans 2001)

Distribution: 

Mexico, Distrito Federal and states of Guanajuato, Hidalgo, México, Michoacán, Puebla, Tlaxcala, Veracruz, 2050-3560 m; a weed in and at the edges of cultivated potato fields, in areas where S. demissum grows, or spread away from these fields along roadsides or fencerows, or among bushes.

Phenology: 
Flowering and fruiting August through October.
Phylogeny: 

Solanum ×edinense belongs to the potato clade of Solanum (Bohs, in press). Solanum ×edinense is of clear hybrid origin between S. demissum and the cultivated species S. tuberosum (Hawkes 1944, 1963; Ugent 1967; Serquen and Hanneman, in press). Solanum ×edinense is very similar in appearance to S. demissum, and like that species has a high-placed pedicel articulation. Solanum ×edinense can have wider leaves than S. demissum (6-12 cm wide vs. 1.5-10 cm wide), and is generally taller than S. demissum (1-2 m tall vs. up to 0.6 m tall); yet, frankly it is impossible to distinguish with confidence all herbarium specimens as one or the other taxon. Solanum ×edinense is easier to identify in the field. All populations Spooner et al. (2004) sampled in Mexico are taller than S. demissum, and all formed fruits with few to no seeds, suggesting S. ×edinenseis sterile. Like other populations previously reported (Rybin 1929, 1933; Hawkes 1944; Hrubý 1957) our gatherings were pentaploid (2n = 5x = 60).

Commentary: 

Hawkes (1990) recognized two subspecies of S. ×edinense: subsp. edinense of putative hybrid origin between S. demissum and S. tuberosum subsp. tuberosum, and subsp. salamanii, a putative hybrid between S. demissum and S. tuberosum subsp. andigenum (Juz. and Bukasov) Hawkes. He distinguished the two subspecies by plant height and corolla color, but in practice he identified all populations collected in gardens in Europe as subsp. edinense and those collected in Mexico as subsp. salamanii. Spooner et al. (2004) observed a range of corolla colors and sizes in Mexico and cannot distinguish subspecies.

References: 

Serquen, F.C., & R.E. Hanneman, Jr. An analysis of the hybrid nature of Solanum edinense Berth. using molecular, cytological and crossability studies.
Potato Res.

Rybin, V.A. 1929. Karyological investigations on some wild growing and indigenous cultivated potatoes of America [in Russian, English summary].
Trudy. Prikl. Bot. 20: 655-720.

Rybin, V.A. 1933. Results of cytological studies on the South American cultivated and wild potatoes and their importance for breeding.
Trudy. Prikl. Bot. Ser II, 2: 3-100.

Hawkes, J.G. 1944. Potato collecting expeditions in Mexico and South America. II.
Systematic classification of the collections, 1-142. Cambridge: Imp. Bur. Pl. Breed. Genet, Imp. Agric. Bur.

Hrubý, K. 1957. Polyploidie a její Význam v p?irod?.
Vesmír 36, 1: 11-15.

Hawkes, J.G. 1963. A revision of the tuber-bearing Solanums. II.
Scott. Pl. Breed. Sta. Rec. 1963: 76-181.

Ugent, D. 1967. Morphological variation in Solanum × edinense, a hybrid of the common potato.
Evolution 21: 696-712.

Hawkes, J.G. 1990. The potato: evolution, biodiversity and genetic resources.
Oxford: Belhaven Press.

Spooner, D.M. & R.J. Hijmans 2001. Potato systematics and germplasm collecting, 1989-2000.
Amer. J. Potato Res. 78:237-268; 395.

Spooner, D.M., R.G. van den Berg, A. Rodríguez, J. Bamberg, R.J. Hijmans, & S.I. Lara-Cabrera 2004. Wild potatoes (Solanum section Petota; Solanaceae) of North and Central America.
Syst. Bot. Monog. 68: 1-209 + 9 plates.

Bohs, L. 2005. Major clades in Solanum based on ndhF sequences.
Pp. 27-49 in R. C. Keating, V. C. Hollowell, & T. B. Croat (eds.), A festschrift for William G. D’Arcy: the legacy of a taxonomist. Monographs in Systematic Botany from the Missouri Botanical Garden, Vol. 104. Missouri Botanical Garden Press, St. Louis.

Taxonomic name: 
Solanum ×edinense (Solanaceae)
Wed, 2013-11-20 10:57 -- sandy
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