1. Family: Fabaceae Lindl.
    1. Genus: Crotalaria L.
      1. Crotalaria trifoliolata Baker f.

        This species is accepted, and its native range is S. Central Ethiopia.

    [KBu]

    Friis, I. & Weber, O. 2014. Crotalaria trifoliolata (Leguminosae: Papilionoideae), a previously incompletely known Ethiopian endemic rediscovered after 120 years. Kew Bulletin 69: 9536. DOI https://doi.org/10.1007/s12225-014-9536-7

    Type
    Type: Ethiopia, ‘Somali-Land, Walenso,’ 26 Oct. 1894 [see discussion of ‘The correct position of the type locality’ above], Donaldson Smith 213 (holotype BM! (BM000843508)).
    Habit
    Shrubby plant with single or several ± 0.8 m high stems from a semi-woody base, most branched in the upper part
    Bark
    Bark on old stems grey, smooth, on young stems covered by a thick grey to ferrugineous tomentum
    Leaves
    Leaves laxly clustered towards the upper part of stems, not long persistent on older parts, often ascending at first, later spreading; internodes ± 1 cm long
    Stipules
    Stipules narrowly triangular to linear-caudate, 4 – 6 × 0.8 – 1 mm, tomentose
    Leaf lamina
    Lamina trifoliolate
    Petiole
    Petioles 2.5 – 4 cm long, with indumentum as on the young stems
    Leaflets
    Leaflets mostly obovate, sometimes elliptic, 2.5 – 5.5 × 2.0 – 3.0 cm, length 1.4 – 1.7 × width; apex rounded or emarginate, sometimes with the midvein ending in a small apical mucro; margin entire; base cuneate; lateral veins 14 – 16, mostly opposite in basal part of the leaflet, becoming alternate in the upper part and forming a lax reticulation near the margin; adaxial side densely and finely pilose with appressed or slightly spreading fine white hairs, margin with longer and more robust white hairs, which are also present on the venation of the abaxial side, shorter and finer half-appressed white hairs between the veins
    Inflorescences
    Inflorescences terminal or leaf-opposed, on peduncles 2 – 4 cm long, with indumentum as on the stems
    Flowers
    Flowers in a raceme with (10 –) 15 – 30 (– 35) flowers, which are densely packed at first (and persistently so at the tip of the inflorescence), becoming laxer during anthesis, with bracts and pedicels 1 – 1.5 cm apart
    Bracts
    Bracteoles appressed to the calyx, often fallen or difficult to see because of the dense ferrugineous tomentum of the calyx, oblong or obovate to narrowly obovate, 1.5 – 2.5 × ± 1 – 1.5 mm, with dense ferrugineous tomentum Bracts linear-caudate, 4 – 6 × 0.8 – 1 mm, finely tomentose on the abaxial side, glabrescent on the adaxial side
    Calyx
    Calyx broadly campanulate, 3 – 4 × 4 – 5 mm excluding calyx lobes, densely ferrugineouslytomentose outside, completely glabrous inside; calyx lobes subequal, narrowly triangular, 3.5 – 6 × 1.5 – 2 mm
    Corolla
    Wings 8 – 9 × ± 3 mm, slightly longer than the keel, of the same colours as the standard Standard broadly elliptic, 8 – 9 × 6 – 7 mm, glabrous outside, yellow, claw 1 – 2 mm long, slightly darker orange-yellow or tinged purplish-brown Keel abruptly rounded a little below the middle, the beak projecting and only slightly incurved at the tip, 8 – 9 mm long from insertion to the round of the up-bent tip, which is 8 – 9 mm long, glabrous except for a line of white hairs along the edge of the proximal half, colour variable from pale yellow to yellow with a purplish-brown; generally the colour of the keel is paler than the standard and wings Corolla pale to dark yellow or yellow-orange; in Friis et al-15074 with the basal parts of the standard, wings and keel sometimes tinged dark orange to brownish-purple, in Donaldson Smith 213 these parts of the flowers are sometimes tinged brighter purplish
    Staminodes
    Staminal tube 7 – 8 mm long
    Ovary
    Ovary 6 – 9 mm long, densely white tomentose; style ± 8 mm long, bent downwards at the insertion on the ovary, curving upwards in the lower ⅓, straight in the apical ⅔, glabrous except for a line of white hairs along the upper side in the apical ⅓
    Stigma
    Stigma capitate, ± 0.3 mm in diam- Legume on 1 – 2 mm long stipe, slightly curved cylindrical with rounded ends or slightly narrowing towards the base, 28 – 31 mm long, ± 8 mm in diam., with white to ferrugineous indumentum; densely packed with tomentum of long white hairs inside, nearly filling the space between the (10 –) 12 – 15 seeds and presumably retaining them in the pod when this opens instantaneously along both sutures
    Seeds
    Seeds triangular cordiform, ± 1.6 × 1.2 × 0.5 mm; surface smooth or with very faint parallel or slightly irregularly placed lines, dark brown
    Figures
    Figs 3 & 4.
    Distribution
    Ethiopia, Oromia Regional State, in the BA floristic region of the Flora of Ethiopia (Hedberg & Edwards 1989). So far documented only from mountains near Sheik Hussein.
    Ecology
    According to our field observations Crotalaria trifoliolata seems to be restricted to edges and glades of dry Juniperus forest on limestone at altitudes above ± 1600 m a.s.l. Thulin (1989: 204), assuming that the collecting locality of the holotype was between Ginir and Sof Omar, indicated the habitat as probably dry bushland at ± 1400 m a.s.l. According to information from the type and our observations the species occurs at (?1650 –) 1850 – 2000 m a.s.l. at the edge of and in glades in dry Juniperusprocera forest growing in thin soil over limestone (Table 1; Figs 1, 2). Friis (1992) and Friis et al. (2010) argue that this type of Juniperusprocera-Olea europaea subsp. cuspidata forest on the eastern escarpment of the Ethiopian highlands and in the mountain chain in northern Somalia represents a floristically distinct vegetation type. Friis et al. (2010) called this vegetation ‘Transition between Afromontane vegetation and Acacia-Commiphora bushland on the eastern escarpment (DAF/TR),’ and determined its altitudinal range from 1500 to 2400 m and its annual rainfall range between 400 and 700 mm. Apart from JuniperusproceraEndl. and Olea europaea L. subsp. cuspidata (G. Don) Cif. in the canopy, it is characterised by BarbeyaoleoidesSchweinf., Cussoniaholstii Engl., TinneasomalensisChiov. and a range of other endemic or near-endemic species in the understorey (Lovett & Friis1996).
    Conservation
    Crotalaria trifoliolata is listed as Endangered (EN) in Walter & Gillett (1998), based on information by Edwards & Asfaw (1992) and Thulin (1983, 1989). Vivero et al. (2005) do not mention C. trifoliolata, nor is it included in the Internet-based IUCN Red List of Threatened Species (IUCN 2013). According to our observations Crotalaria trifoliolata occurs locally in small populations at the forest edge and in open glades in Juniperus forest, where we observed it for a maximum of ± 4 km along the road. These localities are all inside the Kubayo National Forest Priority Area, of which only ± 6% is undisturbed or slightly disturbed, the rest is heavily disturbed forest, forest converted to plantations and land converted to other uses (Kidane Mengistu 2003). We observed settlements and plantations of coffee, qat and oranges inside the area of the forest priority area. A piped water supply from the mountains and the construction of the new road to Sheik Hussein will undoubtedly increase the human pressure on the Kubayo National Forest Priority Area. The fact that C. trifoliolata sometimes survives along roadsides (Fig. 2) will probably not protect it from that pressure. Using our field data and the MaxEnt model prediction (which adds the isolated mountains with limestone within the red square in Map 2 to the area), we estimate the Extent of Occurrence to be less than 1500 km2. The Area of Occupancy based on the auto-value of 6 km cell-width is 164 km2, or 32 km2 using the cell size recommended by IUCN. The area-calculations were carried out using the Geo-Cat tool (Bachman et al. 2011), using the distributional data in Table 1. The modelled distribution is fragmented and we assume from our field observations that the sub-populations are limited in size. The habitat in general is degraded or partly destroyed from road building, cattle grazing and growing pressure from settlements. Based on this we evaluate the species as Endangered (EN), meeting IUCN criterion B1ab(iii) and B2ab(iii) (IUCN 2012).
    Phenology
    Flowering time: Oct. to Dec., possibly longer. Fruiting time: Dec., possibly longer.
    Note
    Our additional information, however, does have relevance for the position of Crotalaria trifoliolata within the subsection. In the key of Polhill (1982: 159), C. trifoliolata keys out in the second lead of couplet 23: ‘Legumes glabrous inside …’ Due to our observation of mature pods, C. trifoliolata must instead key out in the first lead of couplet 23: ‘Legumes (and ovary) packed inside with long hairs …’ and the words ‘stipules absent’ in that couplet must be deleted. C. trifoliolata will then fall in a group of species with long hairs inside the pod (C. leucoclada Baker, C. rhynchocarpa Polhill, C. saltiana Andrews and C. thomasii Harms). This group of species, now also including C. trifoliolata, all occur in or adjacent to the Somalia-Masai regional centre of endemism (White 1983), which extends from Ethiopia and Somalia through Kenya to northern Tanzania. In the protologue (Baker 1896: 53) and in a subsequent taxonomic revision of the genus Crotalaria Baker (1914: 362) compared his new species with the widespread C. incana L. and C. deflersiiSchweinf. C. trifoliolata was accepted and given full treatment in the monograph of the genus in Africa and Madagascar by Polhill (1982: 170), also providing a new description of the holotype. Polhill placed the species in sect. Hedriocarpae Wight & Arn. subsect. Hedriocarpae, next to C. deflersii and C. comanestianaVolkens & Schweinf. The new information does not change the general classification proposed by Polhill (1982: 15). According to our observations C. trifoliolata again keys out as belonging to sect. Hedriocarpae subsect. Hedriocarpae due to the short receptacle, the beak of the keel not being twisted, the simple, curved style and the rather uniformly yellow petals. Given the presence of stipules in Crotalaria trifoliolata, it can be keyed out as the first species after the first lead of couplet 23. C. trifoliolata is somewhat similar to C. leucoclada in habit and stem-indumentum, but differs in the presence of stipules, in having more pilose and larger leaflets (2.5 – 5.5 × 2.0 – 3.0 cm versus 1.5 – 3.5 × 0.6 – 1.8 cm) and in the pods being 28 – 31 mm long, rather than ± 16 mm long. Apart from the presence of stipules, C. trifoliolata differs from the other species in the group with hairs inside the pod in being an erect subshrub with persistent bracts and bracteoles, rather than a spreading bushy plant (C. saltiana) or a plant with long procumbent branches (C. thomasii), or having early caducous bracts and bracteoles (C. rhyncocarpa). Crotalaria leucoclada, the species which morphologically is most similar to C. trifoliolata, has been known only from a few collections made by the end of the 19th century in the mountains of northern Somalia (Polhill 1982: 172; Thulin 1993: 450), but an additional specimen was collected in 1983 from the western escarpment of the AsirMts in Saudi Arabia by Iris Sheila Collenette and annotated by R. M. Polhill as C. leucoclada in 1983 (Collenette 4600; http://elmer.rbge.org.uk/bgbase/vherb/bgbasevherb.php?cfg=bgbase/vherb/zoom.cfg&filename=E00277122.zip&queryRow=1). Comparison of Collenette 4600 and Friis et al. 15074 clearly confirms the distinction between C. trifoliolata and C. leucoclada.
    [ILDIS]

    International Legume Database and Information Service

    Conservation
    Insufficiently known
    Habit
    Not climbing, Herb

    Distribution

    Native to:

    Ethiopia

    Crotalaria trifoliolata Baker f. appears in other Kew resources:

    First published in J. Bot. 34: 53 (1896)

    Accepted by

    • Govaerts, R. (1999). World Checklist of Seed Plants 3(1, 2a & 2b): 1-1532. MIM, Deurne.
    • Lock, J.M. (1989). Legumes of Africa a check-list: 1-619. Royal Botanic Gardens, Kew.

    Literature

    Kew Bulletin
    • Meckelburg, A. (2014). Smith, Arthur Donaldson. In: A. Bausi & S. Ulig (eds), Encyclopaedia Aethiopica, vol. 5, pp. 515 – 517. Harassowitz Verlag, Wiesbaden.Google Scholar
    • Google Earth (2013). Google Earth. Vers. 7.1.2.2041. (Accessed 30 April 2014).Google Scholar
    • ISRIC (2013). SoilGrids: an automated system for global soil mapping. ISRIC – World Soil Information. http://www.isric.org/content/soilgrids (Accessed 30 April 2014).
    • IUCN (2013). The IUCN Red List of Threatened Species. http://www.iucnredlist.org >. (Accessed 30 April 2014).
    • IUCN (2012). IUCN Red List Categories and Criteria. Version 3.1. Second edition. Gland & Cambridge.Google Scholar
    • Bachman, S., Moat, J., Hill, A. W., de la Torre, J. & Scott, B. (2011). Supporting Red List threat assessments with GeoCAT: geospatial conservation assessment tool. In: V. Smith & L. Penev (eds), e-Infrastructures for data publishing in biodiversity science. ZooKeys 150: 117 – 126. and GeoCAT. Geospatial Conservation Assessment Tool. (Version BETA). http://geocat.kew.org/ (Accessed 17 May 2014).
    • Friis, I. , Demissew, S. & van Breugel, P. (2010). Atlas of the potential natural vegetation of Ethiopia. Biol. Skr. 58.Google Scholar
    • Hedberg, I. (2009). The Ethiopian Flora Project — An Overview. In: I. Hedberg, I. Friis & E. Persson (eds.), Flora of Ethiopia and Eritrea. Vol. 8, pp. 1 – 4. Addis Ababa University, Addis Ababa; Uppsala University, Uppsala.Google Scholar
    • CGIAR-CSI (2008). CGIAR-CSI SRTM 90 m DEM Digital Elevation Database. Version 4. CGIAR Consortium for Spatial Information (CGIAR-CSI). http://srtm.csi.cgiar.org/ Index.asp (Accessed 30 April 2014).
    • Phillips, S. J., Anderson, R. P. & Schapire, R. E. (2006). Maximum entropy modelling of species geographic distributions. Ecological Modelling 190: 231 – 259.CrossRefGoogle Scholar
    • Hijmans, R. J., Cameron, S. E., Parra, J. L., Jones, P. G. & Jarvis, A. (2005). Very high resolution interpolated climate surfaces for global land areas. Int. J. Climatol. 25: 1965 – 1978.CrossRefGoogle Scholar
    • Van Wyk, B. E. (2005). Tribe Crotalarieae. In: G. Lewis, B. Schrire, B. Mackinder & M. Lock (eds), Legumes of the World, pp. 273 – 297. Royal Botanic Gardens, Kew.Google Scholar
    • Vivero, J. L., Kelbessa, E. & Demissew, S. (2005). The Red List of Endemic Trees and Shrubs of Ethiopia and Eritrea. Fauna & Flora International, Cambridge.Google Scholar
    • Kidane Mengistu (2003). Country paper: Ethiopia. In Anonymous (ed.): Workshop on Tropical Secondary Forest Management in Africa: Reality and Perspectives. Nairobi, Kenya, 09 – 13 Dec. 2002. Proceedings. FAO, Rome. http://www.fao.org/docrep/006/j0628e/J0628E50.htm (Accessed 30 April 2014).
    • Walter, K. S. & Gillett, H. J. (1998). 1997 IUCN Red List of Threatened Plants. Compiled by the World Conservation Monitoring Centre. IUCN — The World Conservation Union, Gland and Cambridge.Google Scholar
    • Lovett, J. C. & Friis, I. (1996). Patterns of endemism in the woody flora of north-east and east Africa. In: L. J. G. van der Maesen, X. M. van der Burgt & J. M. van Medenbach de Rooy (eds), The Biodiversity of African Plants, pp. 582–601. Kluwer, Dordrecht.CrossRefGoogle Scholar
    • Thulin, M. (1993). Fabaceae (Leguminosae). In: M. Thulin (ed.), Flora of Somalia, vol. 1: 341 – 465. Royal Botanic Gardens, Kew.Google Scholar
    • Edwards, S. & Zemede Asfaw (1992). The status of some plant resources in parts of Tropical Africa. Botany 2000: East and Central Africa. NAPRECA Monograph Series No. 2.Google Scholar
    • Friis, I. (1992). Forests and Forest Trees of Northeast Tropical Africa: Their Natural Habitats and Distribution Patterns in Ethiopia, Djibouti and Somalia. Kew Bull. Addit. Ser. 15.Google Scholar
    • Hedberg, I. & Edwards, S. (1989). Flora of Ethiopia, vol. 3. Addis Ababa and Asmara, Uppsala.Google Scholar
    • Thulin 1989: 204
    • Thulin, M. (1989). Fabaceae (Leguminosae), Subfamily 3: Papilionoideae (Faboideae). In: I. Hedberg & S. Edwards (eds), Flora of Ethiopia. Vol. 3: 97 – 251. Addis Ababa University, Addis Ababa, and Asmara University, Asmara; Uppsala University, Uppsala.Google Scholar
    • Thulin 1983: 163
    • Thulin, M. (1983). Leguminosae of Ethiopia. Opera Bot. 68.Google Scholar
    • White, F. (1983). Vegetation of Africa: a descriptive memoir to accompany the Unesco/AETFAT/UNSO vegetation map of Africa. Nat. Resources Res. no. 20. Unesco, Paris.Google Scholar
    • Polhill 1982: 170
    • Polhill, R. M. (1982). Crotalaria in Africa and Madagascar. A. A. Balkema, Rotterdam.Google Scholar
    • Kazmin, V. (1973). Geological Map of Ethiopia. Geological Survey of Ethiopia, Ministry of Mines, Addis Ababa.Google Scholar
    • Baker 1914: 362
    • Baker, E. G. (1914). The African species of Crotalaria. J. Linn. Soc. Bot. 42: 241 – 425.CrossRefGoogle Scholar
    • Sprague, T. A. (1910 – 1911). Loranthaceae. In: W. T. Thiselton-Dyer (ed.), Flora of Tropical Africa. Vol. 6 (1): 255 – 411. Reeve & Co., Ashford.Google Scholar
    • von Erlanger, C. F. (1904). Berichtübermeine Expedition in Nordost-Afrika in den Jahren 1899 – 1901. Z. Ges. Erdk. Berlin 1904: 89 – 117.Google Scholar
    • Smith, A. D. (1897). Through Unknown African Countries. Edward Arnold, London.Google Scholar
    • Baker 1896: 53
    • Baker, E. G. (1896). New African plants. J. Bot. 34: 49 – 57.Google Scholar
    • Smith, A. D. (1896). Expedition through Somaliland to Lake Rudolf. Geogr. J. (London) 8: 120 – 137, 221 – 239, maps after p. 200. Available at http://www.jstor.org/stable/1773613 (Accessed 30 April 2014).
    Kew Backbone Distributions
    • Lock, J.M. (1989). Legumes of Africa a check-list: 1-619. Royal Botanic Gardens, Kew.

    Sources

    International Legume Database and Information Service
    International Legume Database and Information Service (ILDIS) V10.39 Nov 2011
    http://creativecommons.org/licenses/by/3.0

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. 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 Bulletin
    Kew Bulletin
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. 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