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  1. Family: Solanaceae Juss.
    1. Genus: Solanum L.
      1. Solanum phoxocarpum Voronts.

        One of the wild spiny aubergine species of Africa, Solanum phoxocarpum is a shrub or small tree that grows at high altitudes in Kenyan and Tanzanian mountains. It can grow up to six metres tall, and has unusual long, yellow, pointed fruits and mauve flowers. It was recognised as a new species by Kew botanist Dr Maria Vorontsova during fieldwork in Kenya's Aberdare Mountains in April 2009.

    [KSP]

    Kew Species Profiles

    General Description
    Solanum phoxocarpum is a spiny African tree with bright yellow pointed fruits that may have medicinal properties.

    One of the wild spiny aubergine species of Africa, Solanum phoxocarpum is a shrub or small tree that grows at high altitudes in Kenyan and Tanzanian mountains. It can grow up to six metres tall, and has unusual long, yellow, pointed fruits and mauve flowers. It was recognised as a new species by Kew botanist Dr Maria Vorontsova during fieldwork in Kenya's Aberdare Mountains in April 2009.

    Species Profile
    Geography and distribution

    Native to Kenya and Tanzania, Solanum phoxocarpum lives in open montane woodlands at 2,100 - 3,000 metres above sea level.

    Description There is an opening at the tip of each anther and when bees land on the anthers and 'buzz', pollen shoots out. Long-styled flowers produce fruits if they are fertilised by the bees.

    Overview:   Solanum phoxocarpum is a woody shrub or tree measuring 3 to 6 m tall, with several stems growing out of the ground. It is covered in numerous star-shaped hairs barely visible to the naked eye, each hair being around 0.5 mm wide with 11-16 side rays. The main stems bear large curved prickles measuring 0.6-1.5 cm long. Botanically, these are called prickles rather than spines because the structures arise from the epidermis rather than from inner vascular bundles.

    Leaves: The leaves are 6-8 cm long, dark green above and white-grey underneath.

    Flowers:There are 1-7 flowers in every inflorescence. The lowermost flower is larger than the others, 3 cm in diameter when fully open, and when fertilised can develop into a fruit. The other flowers are 1.7 cm in diameter and produce functional pollen but cannot produce fruit. The petals are pale purple and the anthers are 3.5-4 mm long, with openings at the tips.

    Fruits: The fruit is a berry with an unusual conical shape, apically pointed and retaining the same elongated pointed shape throughout development. There is usually one fruit of 2.8-3.7cm long per fruit-bearing branch. The surface of the fruit is usually smooth and shiny but sometimes has small warts. The fruits are yellow when ripe, held erect on the pedicels while they ripen, and start to hang downwards when mature.

    Seeds: Each berry contains about 30 seeds, 4-4.5 mm long, flat and kidney-shaped.

    Threats and conservation

    Solanum phoxocarpum should not be in danger of extinction because its habitat is protected by a network of National Parks in Kenya and Tanzania, including the Aberdare National Park (Kenya), Mount Kenya National Park (Kenya) and the Ngorongoro Conservation Area (Tanzania).

    In spite of the protection offered by these National Parks, populations of S. phoxocarpum are decreasing both inside and outside of protected areas due to the clearing of land for cultivation. 

    During an expedition in April 2009 scientists visited areas where this species had been recorded during the twentieth century, and in place of many forests there are now only villages and fields. Human activities such as cultivation and village-building have expanded in the areas surrounding the National Parks and pose potential threats to this species.

    Uses

    The following uses have been documented by plant collectors on herbarium specimen labels, though have not yet been verified in the field:

    The plants can be used for hedges (Kenya, recorded in 1939)The fruit is eaten (Kenya, recorded in 1965)Roots are boiled in water and the liquid mixed with a broth and taken as a remedy for gonorrhoea. The ripe dry fruits can also be roasted and then ground to a powder, and mixed with butter to give to babies (although the purpose of this has not been recorded) (Kenya, recorded in 1961) Millennium Seed Bank: Seed storage

    Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

    Description of seeds: 4-4.5 mm long, flat and kidney-shaped

    Number of seed collections stored in the Millennium Seed Bank: One

    Germination testing: 100 % germination was achieved on a germination medium of 1% agar at a temperature of 25°C, with 8 hours of daylight followed by 16 hours of darkness.

    Collaboration leads to discovery

    The discovery of this species was made possible by Tim Pearce of Kew's Millennium Seed Bank Partnership in collaboration with the Kenya 'Seeds for Life' project, the National Museums of Kenya, Patrick Muthoka, and Paul Kirka. 

    During collaborative fieldwork in the Kenyan Aberdare mountains in 2009, seeds of Solanum phoxocarpum were collected for seed-banking at the same time as the distinctness of this species was firmly established by Kew botanist Dr Maria Vorontsova.

    This species at Kew

    There are 17 preserved specimens of Solanum phoxocarpum held in Kew's behind-the-scenes Herbarium. It was these collections that prompted the recognition of S. phoxocarpum as a new species and the expedition to find living specimens in Kenya.

    Distribution
    Kenya, Tanzania
    Ecology
    Open montane woodlands.
    Conservation
    Not yet assessed according to IUCN criteria.
    Hazards

    It seems that the fruits could be poisonous - in 2009 a staff member on the Kenya 'Seeds for Life' project was preparing seeds for storage and became unwell after inhaling the vapours from cut fruits.

    [FTEA]

    Solanaceae, Jennifer M Edmonds. Oliganthes, Melongena & Monodolichopus, Maria S. Vorontsova & Sandra Knapp. Flora of Tropical East Africa. 2012

    Type
    Type: Kenya, Masai District, Lake Naivasha to Nasampolai [Enesambulai] Valley, crest of the Western Rift Wall, Greenway & Kanuri 13869 (EA!, holo.; K!, iso.)
    Habit
    Shrub or tree, erect, 1–3(–6) m, armed, young stems densely stellate-pubescent, trichomes multangulate, white-translucent, irregular and densely matted, sessile, rays 11–16, 0.1–0.2 mm, midpoints same length as rays or up to 0.8 mm long; prickles straight becoming gently curved, 6–15 mm long, 2–7 mm wide at base, rounded to flattened
    Leaves
    Leaf blades drying strongly discolorous, reddish-green above, white-grey underneath, elliptic, 6–8 × 2.5–4 cm, ± 2.5 times longer than wide, base cuneate, usually equal, margin subentire to weakly lobed, the broadly rounded lobes 1–2(–3) on each side, up to 0.5(–1.5) cm long, extending up to 1/3 of the distance to the midvein, apex acute; densely stellate-pubescent abaxially, trichomes on abaxial surface porrect and multangulate, sessile and stalked, stalks ± 0.1(–0.2) mm, rays 11–16, 0.15–0.3 mm, midpoints same length as rays or up to 0.8 mm, adaxially glabrescent; primary veins (4–)5–6 pairs; petiole 0.5–0.9 cm, ± 1/6 or less of the leaf length
    Inflorescences
    Inflorescences 3–5.5 cm long, not branched, with 1–7 flowers; peduncle 0–6 mm long; rachis 0–0.3 cm long; peduncle and rachis unarmed; pedicels 1.8–3 cm on long-styled flowers, 0.8–1.2 cm on short-styled flowers, in fruit 2.5–4 cm long, usually with 2–10 prickles
    Flowers
    Flowers heterostylous, 5(–6)-merous, the basal 1–3 long styled
    Calyx
    Calyx ± 15 mm on long-styled flowers, ± 7 mm long on short-styled flowers, lobes long-deltate, 7–10 mm on long-styled flowers, ± 4 mm long on short-styled flowers, acute to apiculate, unarmed or with up to 15 prickles in long-styled flowers
    Corolla
    Corolla mauve, ± 3 cm in diameter on long-styled flowers, ± 1.7 cm in diameter on short-styled flowers, lobed for 1/2–2/3 of its length, lobes deltate, 10–15 × 4–5 mm on long-styled flowers, 6 × 3–4 mm on short-styled flowers
    Stamens
    Stamens equal; anthers 3.5–4 mm
    Ovary
    Ovary stellate-pubescent in the upper 1/5; style ± 7 mm long on long-styled flowers
    Fruits
    Berries 1–3(–5) per infructescence, evenly green when young, yellow at maturity, conical, 2.8–3.7 × 1.8–2.2 cm, acute; fruiting calyx with 0–10 prickles
    Seeds
    Seeds 4–4.5 × 3–4 mm
    Ecology
    Woodland, moist forest understorey or secondary scrub; 2100–3000 m
    Note
    Fully sympatric with the closely related S. aculeastrum, S. phoxocarpum can be recognised by the unusual cylindrical pointed fruits, subentire leaves on fertile branches, and mauve flowers. Solanum phoxocarpum and S. aculeastrum frequently grow together but no intermediate individuals have been observed. Morphology of S. aculeastrum is reminiscent of typical juvenile Solanum morphology with more leaf lobing and abundant prickles, while the morphology of S. phoxocarpum is more similar to the typical mature Solanum morphology with more entire leaves and fewer prickles. Udo Dammer also recognised the distinctness of these plants and annotated the sheet Scheffler 306 (K) as “ Solanum sepiaceum Dammer var. fructile verrucans spec. nov.” in his handwriting, with a printed label “Brit. Uganda. Station Lamuru. Buschiges Hochland. b.c. 3000 m”. This name does not seem to have been published and the specimen is not cited in the protologue of S. sepiaceum Dammer. “Station Lamuru” refers to Limuru in Kenya.
    Distribution
    Flora districts: K3 K4 K6 T2 T3 Range: Not known elsewhere
    [KSP]
    Use
    Medicinal, hedging, possibly edible.

    Images

    Distribution

    Native to:

    Kenya, Tanzania

    Common Names

    English
    Osigawai

    Other Data

    Solanum phoxocarpum Voronts. appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    May 1, 2009 Greenway, P.J. [13869], Kenya K000441270 isotype
    May 1, 2009 Gillett, J.B. [16766], Kenya K000441257
    May 1, 2009 Bally, P.R.O. [B7438], Kenya K000441263
    May 1, 2009 Bally, P.R.O. [B4141], Kenya K000441272
    May 1, 2009 Glover, P.E. [935], Kenya K000441266
    May 1, 2009 Verdcourt, B. [3725], Kenya K000441267
    May 1, 2009 Verdcourt, B. [3725], Kenya K000441268
    May 1, 2009 Frame, G.W. [229], Tanzania K000441259
    Dec 31, 2008 Saint Clair Thompson, G.W. [1255], Tanzania K000441273
    Dec 30, 2008 Hepper, F.N. [4910], Kenya K000441265
    Dec 30, 2008 Hepper, F.N. [4910], Kenya K000441269
    Dec 30, 2008 Robertson, S.A. [4404], Kenya K000441262
    Dec 30, 2008 Williams, J.G. [63], Kenya K000441260
    Dec 30, 2008 Evans, I.B.P. [1468], Kenya K000441256
    Dec 30, 2008 Tweedie, J. [4315], Kenya K000441261
    Dec 30, 2008 Mbale, M. [NMK844], Kenya K000441258
    Kimeu, J.M. [KARI22/02], Kenya K001157858

    Bibliography

    First published in Syst. Bot. 35(4): 903 (2010)

    Accepted by

    • PBI Solanum Project (2014-continuously updated). Solanaceae Source: a global taxonomic resource for the nightshade family http://www.solanaceaesource.org/.

    Literature

    Kew Species Profiles

    • Edmonds, J.E., Vorontsova, M.S. & Knapp, S. 2012. Solanaceae. In: Flora of Tropical East Africa, ed. H. Beentje, Royal Botanic Gardens, Kew.
    • PBI Solanum Project (2010). Solanaceae Source.
    • Vorontsova, M.S., Christenhusz, M.J.M., Kirika, P. & Muthoka, P. (2010). Three new species of Solanum from Kenya: using herbarium specimens to document environmental change. Systematic Botany 35: 894-906.
    • Lambrechts, C., Woodley, B., Church, C. & Gachanja, M. (2003). Report on the Aerial Survey of the Destruction of the Aberdare Range Forests. United Nations Environment Programme, Nairobi.

    Flora of Tropical East Africa

    • Syst. Bot. 35: 903 (2010).

    Sources

    Flora of Tropical East Africa
    Flora of Tropical East Africa
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Herbarium Catalogue Specimens
    'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2020. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Species Profiles
    Kew Species Profiles
    http://creativecommons.org/licenses/by-nc-sa/3.0