New varieties of Trifolium semipilosum in Ethiopia

Mats Thulin

Thulin, M. 1982. New varieties of Trifolium semipilosum in Ethiopia. -Nord. J. Bot. 2: 51-52. Copenhagen. ISSN 0107-055X.

Two new varieties, Trifolium semipilosum Fresen. var. brunellii Thulin and var. in- termedium Thulin, are described from the Ethiopian highlands.

M . Thulin, Inst. of Systematic Botany, Univ. of Uppsah, Box 54I, S-7.51 21 Uppsala, Sweden.

Introduction

Trifolium semipilosum Fresen. (Leguminosae-Papilio- noideae) is distributed in E and N E Africa and Yemen. In many areas, particularly in Ethiopia and Kenya, it is a common and important constituent of the upland grasslands and pastures. Gillett (1952) recognized four varieties within the species, only two of which, var. semipilosum and var. glabrescens Gillett were main- tained in a later treatment (Gillett 1971). Gillett (1952) also discussed some Ethiopian plants which could not be placed in any of the recognized varieties. Owing to the sparse material then available, the taxonomic status of these plants was left undefined. Much more material has now accumulated in the herbaria, showing that two un- described, usually easily recognizable, taxa are in- volved. For the forthcoming paper “Leguminosae of Ethiopia” it seems highly desirable that names are given to these taxa, which are here both described as new varieties of T. semipilosum.

T. semipilosum Fresen. var. brunellii Thulin var. nov. Type: VBtova 717, Ethiopia, Sidamo, Irba Moda, 17 Nov 1937 (FT holotype).

Varietas nova a var. semipiloso et var. glabrescenti foliolis per superficies ambas pilosis et p a t e libera stipularum oblongo-lanceolata ad apicem obtusa cum acumine brevi differt.

Prostrate perennial herb, rooting at the nodes. Leaflets obovate, deeply emarginate at the apex,sparsely to den- sely pilose with & appressed hairs over all of both surfaces; margin usually distinctly toothed. Stipules with the free part oblong-lanceolate, several-nerved, ab- ruptly contracted into a short point. Inflorescences 3-12-flowered. Corolla white to pink, 10-13 mm long. Calyx 4-5.5 mm long; lobes equalling or shorter than the tube, narrowly triangular usually with subulate tips. Ovary & pilose or subglabrous.

Distribution and habitat. T. semipilosum var. brunellii is known from Arssi, Bale and Sidamo Regions in Ethiopia. It occurs in upland grassland and forest mar- gins at 1800-3700 m alt.

Taxonomic remarks. Fiori (1949: 342, Fig. 12) used the name T. brunellii Chiov. ex Fiori (nom. nud.) for this plant. The epithet is retained when the plant is here described as a variety. Reports of the East African T. semipilosum var. glabrescens from Ethiopia by Gillett (1971: 386) and Froman (1975: 65, Fig. 70) certainly refer to var. brunellii. These two varieties agree in the shape of the leaflets, but the indumentum is denser in var. brunellii and both surfaces of the leaflets are pilose all over. The free part of the stipules is also wider in var. brunellii and the flowers are fewer per inflorescence, larger (corolla 10-13 mm versus 8-9 mm), and more often pink.

Locally var. semipilosum and var. brunellii grow to- gether and may then appear to represent distinct species. Nevertheless, as the morphological differences

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4. Nord. J. Bot. 2(1) 1982 51

between these taxa are in most respects bridged by var. glabrescens and var. intermedium, varietal rank seems most appropriate. There are also a few collections from Ethiopia which cannot readily be placed in any of the varieties here recognized.

Ser. ssp. johnstonii (Oliv.) Cuf. ex Gillett). Gillett (1952: 386) regarded the same plants as intermediates of possible hybrid origin between T. semipilosum and T. burchellianum. No chromosome counts have been made on var. intermedium or var. brunellii, but var. semi- Dilosum is a diuloid with 2n=16 (Fedorov 1969). T.

Collections other than the type. Ethiopia. Arssi, above Asella, 20 Dec 1953, Mooney 5157 (K). Bale, Mt Fad, 5 Mar 1954, Smeds 328 (H); Vorkuna, 2 Oct 1957, Smeds s.n. (H), 663 (FT); Rira, 10 Jan 1958, Smeds s.n. (H), 806 m); S Bale, 24 Mar 1958, Eriksson 392 (S); Angasu, 39"52'E, 6"57'N, 15 Dec 1959, Mooney 8300 (FT, K); Tjantjo, 6 Feb 1962, Smeds s.n. (H); 125 km E of Shashemane towards Goba, Chercher Highlands, 4 Feb 1964, Thomas 27 (K); Bale Mts National Park, near the Headquarters, 4 Nov 1973, Hedberg 5715 (UPS), 17 Nov 1979, Mesfin 666 (ETH, UPS). Sidamo, Irba Moda-Agere Selam, 17 Nov 1937, VBtova 33 (FT); S of Wondo, 6"35'N, 38"23'E, 30 Dec 1952, Gillett 14781 (K); Garamba, 6 Feb 1954, Smeds 266 (H), 16 Mar 1958, Eriksson 232 (S); Arbagona, 8 Feb 1954, Smeds 283 (H), 15 Mar 1958, Eriksson 203 (S); Agere Selamdrbagona, 13 Apr 1958, Eriksson 584 (S); Agere Selam, 18 Nov 1967, Westphal 2712 (C, WAG); 43 km S of Agere Selam on the road to Kebre Mengist, 6"12'N, 38"42'E, 1 Nov 1972, Friis et al. 752 (C).

burchellianum iH known to be a poiyploid with 2n=48 or 96 (Fedorov 1969, Hedberg & Hedberg 1977). Bath these numbers have also been counted in Ethiopian material of T. burchellianum (Ryding unpubl.). Hybrids between T. semipilosum and T. burchellianum therefore should have a reduced fertility. The pollen of var. inter- medium as well as of var. brunellii, however, is perfectly fertile and also the seed-setting seems normal. With their deflexed pedicds in fruit stage, pubescent leaflets and white, pink or purplish flowers both these varieties are morphologically connected with T. semipilosum. In the shape and pubescence of the leaflets as well as in the shape of the stipules, var. intermedium is intermediate between var. semipilosum and var. brunellii, but the flowers are more strongly coloured than in the other two varieties mentioned.

Collections other than the type. Ethiopia. Shoa, Entoto, 3 May 1909, Negri 288 (FT); Mussolini Pass above Debre Sins, 15 T~semi~iloswnFresenOvar~intermediumThulin Vgr*nov*

Type: W. de Wilde 7400, Ethiopia, Shoa, Mussolini Pass, be- tween Debre Berhan and Debre Sina, 23 Jul 1965 (WAG holotype, C, K, UPS isotypes).

Varietas nova a var. semipiloso et var. glabrescenti

Jun 19375 Senni 956'(FTh 18 1937, Semi 895 (m, K fragment), 29 Oct 1937, Semi 1954 (m), 7 SePt 19619 Ouren 21208 (BG), 23 Jan 1963, Hagos 218 (K); Jetabon daget, 5 Sept 1957, Smeds s.n. (H). Arssi, 25 km SE of Asella, W slope of Mt Boruluccu, 11 Sept 1965, W. de Wilde 8084 (C, K, UPS, ,,,,,,-,, nnu J,

foliolis per superficies ambas pilosis et a var. brunellii foliolis ad apicem non profunde emarginatis, parte lib- era stipularum apicem versus gradatim angustata et calycis lobis subulatis plerumque tub0 longioribus dif- fert.

Prostrate perennial herb, rooting at the nodes. Leaflets oblong-elliptic to obovate, shallowly emarginate at the apex, sparsely pilose with 2 appressed hairs on both sides or subglabrous above; margin usually distincfy toothed. Stipules with the free part narrowly triangular, few-nerved, tapering f gradually towards the apex. In- florescences (5-)10-15-flowered. Corolla 10-13 mm long, purplish, at the apex pale purple or whitish. Calyx 5-6.5 mm long; lobes subulate, usually longer than the tube. Ovary without long hairs.

Distribution and habitat. This variety is known from Shoa and Arssi Regions in Ethiopia, where it occurs in upland grassland in rocky places at 2800-3800 m alt.

Taxonomic remarks. Fiori (1949: 342) treated some specimens from near Debre Sina, here referred to var. intermedium, as T. johnstonii Oliv. (= T. burchellianum

Acknowledgements - I am indebted to the Directors and Curators of the Herbaria in BG, C, ETH, FT, H, K, S and WAG, for placing material at my disposal. Financial support has been given by the Swedish Natural Science Research Council.

References Fedorov, A. (ed.). 1969. Chromosome numbers of flowering

plants. - Academy of sciences of the USSR, Leningrad. Fiori, A. 1949. Chiave analitica ed illustrazione delle specie di

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Froman, B. 1975. An illustrated guide to the pasture legumes of Ethiopia. -Rural development studies No. 3. College of Agriculture, Uppsala.

Gillett, J. B. 1952. The genus Trifolium ih southern Arabia and in Africa south of the Sahara. -KewBull. 7: 367404.

- 1971. Trifolium. - In: Milne-Redhead. E. & Polhill, R. M.

335-346.

(eds.), Fiora of Tropical East Africa, Leguminosae (Part 4) subfamily Papilionoideae (2). -Crown Agents for Oversea Governments and Administrations, London.

Hedberg, I. & Hedberg, 0. 1977. Chromosome numbers of afroalpine and afromontane angiosperms. - Bot. Notiser 130: 1-24.

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