Solanaceae Source

A global taxonomic resource for the nightshade family

Solanum lesteri

Primary tabs

Citation author: 
J. G. Hawkes & Hjerting
Citation: 
Scott. Pl. Breed. Stat. Rec. 1963: 126, 171. 1963.
Type: 
Cultivated from MEXICO. Oaxaca: Mpio. Miahuatlán, road from Oaxaca to Puerto Ángel, 16 mi S of Miahuatlán, very damp bank above road in shade of bushes and trees, rich soil, 2300 m, 19 Oct 1958, J. G. Hawkes, J. P. Hjerting, & R. N. Lester 1714 (lectotype: a fruiting specimen cultivated in greenhouse and labeled as sheet 1, K, bearing a young fruit!; isolectotype: specimen labeled as sheet 2, K!, bearing flowers!).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M.
Habit: 
Herbaceous tuber-bearing perennials 0.4-1.5 m tall. Stems 4-7 mm in diameter at base of plant.
Sympodial structure: 
Sympodial units typically 3-6-foliate.
Leaves: 
Pseudostipules to 3-10 mm long, lunate. Leaves odd-pinnate, 9-22 cm long, 6-14 cm wide, pubescent to pilose, densely covered with short-stalked “type A” glands adaxially and abaxially and with short spreading hairs; petioles 1-5 cm long; lateral leaflet pairs 3-6, the size of the lateral leaflets not diminishing towards the base of the leaf, the second pair of laterals often longer than the first; most distal lateral leaflets 2.5-8 cm long, 1-2.6 cm wide, ovate to elliptical, apex acute to acuminate, base oblique, cuneate to cordate, typically sessile, rarely short-petiolate or decurrent; terminal leaflet 4-10 cm long, 1.6-3.5 cm wide, ovate to elliptcal, apex acute to acuminate, base attenuate; interjected leaflets 2-11.
Inflorescences: 
Inflorescence a dichasially branched, ebracteate, monochasial or dichasial cyme, 2-3 forked, generally in the distal half of the plant, with 5-24 flowers, all flowers perfect, peduncle 5.5-9 cm long; pedicels 14-50 mm long, articulate between the proximal ¼ and the distal ¼.
Flowers: 
Flowers with the calyx 4-7 mm long, lobes acute to long-attenuate, acumens 2-3 mm long. Corollas 1.8-3.5 cm in diameter, pentagonal to rotate, acumens 3 mm long, edges of corolla flat, not folded dorsally, white. Anthers 4-6 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 2-4 mm, straight, with stigma globose.
Fruits: 
Fruits 2.2-3 cm in diameter, triangular in outline, widest near the base, 1.7-2.2 times as long as wide, green, sometimes with longitudional dark purple stripes.
Seeds: 
Seeds from living specimens 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 =24 voucher missing = (Spooner & Hijmans 2001)

Distribution: 

Mexico: Oaxaca, 2100-2390 m; in areas of alder, pine and oak woods, in clearings along roadsides or in shade.

Phenology: 
Flowering and fruiting September through October.
Phylogeny: 

Solanum lesteri belongs to the potato clade of Solanum (Bohs, in press). Spooner and Sytsma (1992) placed S. lesteri and all other North and Central American diploids (exclusive of S. bulbocastanum, S. cardiophyllum, and S. verrucosum) in the basal “clade 1” of section Petota based on chloroplast DNA restriction site data. Spooner et al. (2004) placed S. lesteri and S. polyadenium in the Polyadenia group. Solanum lesteri and S. polyadenium clearly are sister taxa that are united by cpDNA data (Spooner and Sytsma 1992), morphological data (Lara-Cabrera and Spooner, in press a) and AFLP data (Lara-Cabrera and Spooner, in press b). As a group they are very easily distinguished in the field by their highly glandular leaves with Type A (short-stalked glandular) trichomes, their characteristic strong “mousy” odor, and on herbarium specimens with a yellowish or yellow-brown color to the foliage (green in other species).

Commentary: 

Solanum lesteri is easily distinguished in the field by its highly glandular leaves with a dense covering of Type A trichomes, its characteristic strong “mousy” odor, and on herbarium specimens with a yellowish or yellow-brown color to the foliage. It could be confused only with S. polyadenium but the two species are distinguished by fruit shape. Solanum lesteri has fruits triangular in face view (1.7-2.2 times as long as wide) and S. polyadenium has fruits globose or if triangular only up to 1.7 times as long as wide.

Hawkes (1963) designated a collection of S. lesteri at K as “type” and listed another possible isotype at JGH (his personal herbarium, later sent to K). It is unclear what specimen, if any, represents this possible JGH isotype. At K are three specimens from plants cultivated in a greenhouse; two are labeled as sheet 1 (our lectotype, bearing a young fruit) and sheet 2 (bearing flowers), and a third sheet is unlabeled (large leaves, flowers in a packet).. A note showing through the isolectotype label sheet 2 indicates it was cultivated in a greenhouse. The time and date of cultivation are not listed on the type sheets or in Hawkes (1963). Other specimens at K and other herbaria sometimes bear dates of cultivation that differ and could have been cultivated later. It is unclear if these other specimens represent later gatherings; because of this ambiguity Spooner et al. (2004) only considered as type material the lectotype and isolectotype.

References: 

Lara-Cabrera, S. & D.M. Spooner Taxonomy of Mexican diploid wild potato (Solanum sect. Petota) species: AFLP data.
Plant Syst. Evol.

Lara-Cabrera, S. & D.M. Spooner Taxonomy of Mexican diploid wild potato (Solanum sect. Petota) species: morphological and microsatellite data.
Monogr. Syst. Bot., Missouri Bot. Gard.

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

Spooner, D.M. & K.J. Sytsma 1992. Reexamination of series relationships of Mexican and Central American wild potatoes (Solanum sect. Petota): evidence from chloroplast DNA restriction site variation.
Syst. Bot. 17:432-448.

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

Lara-Cabrera, S.I. 2001. Taxonomy of Mexican diploid wild potato (Solanum sect. Petota) species: a morphological and molecular study.
Ph.D. Thesis, Plant Breeding and Plant Genetics Program, University of Wisconsin-Madison.

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.

Genetics: 

Chloroplast DNA restriction site data available in: Spooner and Sytsma (1992). AFLP, morphological, and microsatellite data listed in: Lara-Cabrera (2001).

Taxonomic name: 
Solanum lesteri (Solanaceae)
Wed, 2013-11-20 11:00 -- sandy
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith