Solanaceae Source

A global taxonomic resource for the nightshade family

Revision of Solanum andreanum from Thu, 2013-12-19 16:26

Citation author: 
Baker
Citation: 
J. Linn. Soc. 20: 498. 1884.
Type: 
Colombia. Nariño: between La Unión and Meneses, 2400 m, 29 Apr 1876, E. André 2873 pro parte (holotype, K0000005763 [Correll neg. 58, BM000882147, F-1604856, LL, NY, UC1152166]; isotypes, K [Correll neg. 57, BM000882148, F-1604853, LL, MO-5588716, NY, UC1152166], NY00259402 [Correll neg. 87, BM000882146, F-1604834, LL, NY, UC1152166]).
Last edited by: 
Spooner, D.M.
Written by: 
Spooner, D.M. & M. Ames
Habit: 
Herbs 0.06-0.86 m tall, generally erect but sometimes a rosette. Stems 1-9 mm in diameter at base of plant, generally unwinged, glabrous to glabrescent; tubers typically moniliform (multiple tubers arranged along the stolon like beads on a necklace).
Sympodial structure: 
Sympodial units tri- to plurifoliate, not geminate.
Leaves: 
Leaves odd-pinnate, the blades 3.2-22 x 2.2-13.3 cm, dark green adaxially, light green abaxially, coriaceous, glabrescent adaxially and abaxially, with very short hairs; lateral leaflet pairs 1-4, decreasing in size toward the leaf base, with the terminal leaflet generally subequal to the laterals; most distal lateral leaflets 1.1-7.9 x 0.5-3.2 cm, ovate to elliptic, the apex acute to acuminate, the base typically sessile and attenuate to rounded, asymmetric with more tissue on the basiscopic side, slightly decurrent on the rachis; terminal leaflet 2-8.5 x 1.2-5.5 cm, ovate to elliptic, the apex acute to acuminate, the base generally attenuate; interjected leaflets 0-39, generally sessile, ovate to orbicular; petioles 0.4-3 cm, glabrescent with short hairs. Pseudostipules 1-13 mm long, subglabrous to glabrescent.
Inflorescences: 
Inflorescences 3.2-23 cm, terminal with a subtending axillary bud, generally in distal half of the plant, usually forked, with 2-43 flowers, with all flowers apparently perfect, the axes glabrous to glabrescent with long white hairs; peduncle 0.38-11.3 cm long; pedicels 7-47 mm long in flower and fruit, spaced 3-5 mm apart, articulated in the middle to high in the distal half.
Flowers: 
Flowers homostylous, 5-merous. Calyx 2-10 mm long, the tube 2-5 mm, the lobes 0.3-11 mm, ovate to lanceolate, with linear acumens 0.3-6 mm long, glabrous to glabrescent with white short hairs. Corolla 2-4.9 cm in diameter, pentagonal to rotate, lilac to blue, the tube 1-2 mm long, the acumens 1-5 mm long, the corolla edges flat, not folded dorsally, glabrous adaxially and abaxially, sometimes glabrescent on the corolla acumens with short white hairs. Stamens with the filaments 1-2 mm long; anthers 3-11 mm long, lanceolate, connivent, yellow, poricidal at the tips, the pores lengthening to slits with age. Ovary glabrous; style 3-10 mm x ca. 1 mm, exceeding stamens by 0-7 mm, straight, glabrous; stigma clavate to capitate.
Fruits: 
Fruit a globose berry to ovoid berry, 0.5-2.3 cm wide, 0.7-2.6 cm long, medium to deep green sometimes with dark green stripes when ripe, glabrous.
Seeds: 
Seeds from living specimens ovoid and ca. 2 mm long, whitish to greenish in fresh condition and drying brownish, with a thick covering of “hair-like” lateral walls of the testal cells that make the seeds mucilaginous when wet, green-white throughout; testal cells honeycomb-shaped when lateral walls removed by enzyme digestion.
Chromosome number: 

2n = 2x = 24 voucher: Spooner, Castillo-T & López-J 5152 (PTIS) (Hijmans, et al. 2007)
2n = 4x = 48 voucher: Spooner, Castillo-T & López-J 5007 (PTIS) (Hijmans, et al. 2007)

Distribution: 

Solanum andreanum occurs throughout Ecuador and in adjacent southern Colombia, near creeks, among herbs or shrubs. Diploid populations usually grow between 1900-3700 m and polyploid populations between 2200-4000 m in elevation.

Phenology: 
Flowering and fruiting mainly from April to July although some flowering and fruiting collections have been made throughout the year.
Phylogeny: 

Solanum andreanum is a member of Solanum sect. Petota Dumort., the tuber-bearing cultivated and wild potatoes. Within sect. Petota, Solanum andreanum is a member of a distinctive clade of southern Ecuadorian and Peruvian species formerly classified in series Piurana and some other series that frequently possess moniliform tubers and shiny coriaceous leaves. On a higher taxonomic level, it is a member of the informally-named Potato Clade, a group of perhaps 200-300 species that also includes the tomato and its wild relatives (Bohs, 2005).

Commentary: 

Solanum andreanum is morphologically diverse, with some of the tetraploid cytotypes sometimes being more robust. Based on field work in Colombia and Ecuador and comparative morphological data from herbarium specimens, Spooner et al. (1993) synonymized under S. andreanum the diploid species S. baezense, S. cyanophyllum, S. pichinchense, S. serratoris, and S. suffrutescens. Subsequently, we also discovered S. baezense, S. correllii, and S. regularifolium to also be synonyms. Based on unpublished molecular data from single-copy DNA sequences and morphological data from Ames and Spooner (2008), we also synonymize under S. andreanum the names S. paucijugum, S. solisii, and S. tuquerrense that refer to tetraploid populations. These are morphologically indistinguishable from S. andreanum and related to it, although S. paucijugum and S. tuquerrense are supported as of allopolyploid origin with other species farther to the south in Peru. Their common occurrence in southern Colombia and Ecuador, their morphological similarity, and common relationships (despite allopolyploid origins of the tetraploids) lead us to subsume all these names into one.

Our concept of S. andreanum includes diploids and allopolyploids of S. andreanum and very closely related members of clade 3 (the Piurana clade) that are impossible to distinguish morphologically from S. andreanum. To distinguish S. andreanum from the other related wild potatoes within clade 3 (Piurana clade) it is necessary to consider two factors, geographical distribution and morphological habit. Solanum andreanum is restricted to southern Colombia and Ecuador and overlaps with S. olmosense, S. chilliasense, S. minutifoliolum, S. albornozii, and S. chomatophilum. Solanum olmosense has leaves widely decurrent onto the rachis and S. andreanum has leaves without a decurrent rachis. Solanum chilliasense has terminal leaflets considerably larger than the lateral leaflets and S. andreanum has terminal leaflets equal to or slightly larger than the lateral leaflets. Solanum minutifoliolum has densely hairy leaves and S. andreanum has glabrous to subglabrous leaves. Solanum albornozii has narrow leaflets and more revolute margins and S. andreanum has wider leaflets and straight margins. The morphological distinction between some populations of S. chomatophilum and S. andreanum is difficult but S. andreanum is often a larger plant and has slightly pubescent to subglabrous leaves whereas S. chomatophilum is a smaller plant and can have completely glabrous leaves.

References: 

Spooner, D. M., R. Castillo-T. & L. E. López-J 1993. Synonymy within wild potatoes (Solanum sect. Petota: Solanaceae): the case of Solanum andreanum.
Syst. Bot. 18: 209-217.

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.

Hijmans, R., T. Gavrilenko, S. Stephenson, J. Bamberg, A. Salas & D.M. Spooner 2007. Geographic and environmental range expansion through polyploidy in wild potatoes (Solanum section Petota).
Global Ecol. Biogeogr. 16: 485-495.

Ames, M., A. Salas & D.M. Spooner 2008. A morphometric study of species boundaries of the wild potato Solanum series Piurana (Solanaceae) and putatively related species from seven other series in Solanum sect.
Petota. Syst. Bot. 33: 566-578.

Taxonomic name: 
Solanum andreanum (Solanaceae)
Wed, 2013-11-20 10:57 -- 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