New and noteworthy species of Indigofera (Leguminosae) from NE Africa

Mats Thulin

Thulin, M. 1982. New and noteworthy species of Indigofera (Leguminosae) from NE Africa. - Nord. J. Bot. 2: 41-50. Copenhagen. ISSN 0107-055X.

Six new species of Indigofera are described: 1. eremophila Thulin from E Ethiopia, I. mooneyi Thulin from the highlands of SW Ethiopia, I. boranica Thulin from SE Ethiopia and NE Kenya, I. gyrafa Thulin and I. ammophila Thulin from NE Kenya, and I. cana Thulin from north-central Ethiopia. 1. cavaNii Chiov., previously known only from the type from S Somalia, is reported also from NE Kenya.

M . Thulin, Inst. of Systematic Botany, Univ. of Uppsala, Box 541, S-751 21 Uppsala, Sweden.

Introduction

During the preparation of the forthcoming paper “Leguminosae of Ethiopia” a number of undescribed taxa of hdigofera L. from NE Africa have come to light. Material and evidence sufficient for their publica- tion is available for some of them and descriptions of these species are given in this paper along with a new record for Kenya of I. cavallii Chiov.

Indigofera was revised for tropical Africa by Gillett (1958) and by this work the classification of the genus in this area was put on a firm basis. Gillett (1971) re- corded 145 species from tropical East Africa (Uganda, Kenya and Tanzania). In Ethiopia about 74 species are now known, some of which are still undescribed.

I. eremophila Thulin sp. nov. Type: Gilbert 2090, Ethiopia, Harerghe Region, 35 km S of Geladi, 6”45’N, 46’20’E, 14 Jun 1971 (K holotype, ETH isotype).

Species nova ab I. vohemarensi Baill. indumento argenteo, inflorescentiis floribus 10-25 pedunculo 2-12 mm longo, foliis foliolis 3-5 obovatis periolo 3-9 mm longo et calyce 2-2.5 mm longo sinu vexillari aliis multo latiore differt.

Slender shrublet up to 50 cm high, silvery strigose throughout with appressed or somewhat spreading hairs; older stems with flaking epidermis, becoming purplish brown. Leaves pinnately 3-5-foliolate; rhachis 5-14 mm long including a petiole of 3-9 mm; petiolules ca. 0.5 mm long; leaflets obovate, 4-9 X 2-5 mm, rounded to emarginate at the apex, cuneate at the base, often folded and with a downcurved tip; stipels filiform, ca. 0.5 mm long; stipules lanceolate-subulate, 2-2.5 mm long. Racemes fairly dense, ca. 10-25-flowered, 1.5-8 cm long, including a peduncle of 0.2-1.2 cm; bracts lanceolate-subulate, ca. 1.5 mm long, caducous; pedicels 1.2-2.5 mm long, k erect in fruit. Calyx 2-2.5 mm long, divided to about the middle into narrowly triangular lobes; the vexillar sinus much wider than the others. Corolla bright pink; standard very broadly ovate, ca. 5.5 mm long, broadly rounded at the apex, truncate at the base, white pubescent on the back; wings ca. 4 x 1.2 mm, sparsely ciliate along lower margin, shortly clawed; keel ca. 5.5 mm long, bluntly spurred at each side, not beaked, pubescent near the apex along the lower margin and ciliate near the middle along the upper margin, with claws ca. 1.5 mm long. Stamens all fertile, ca. 5 mm long; anthers ovate, ca. 0.7 mm long including the ca. 0.2 mm long acute apical appendage. Ovary strigulose, linear, several-ovulate; style ca. 1.6 mm long, upcurved, glabrous; stigma capitate, terminal.

8 NORDIC JOURNAL OF BOTANY

NORD. 1. BOT. 2: 41-50, TROP 031 41

D 0

E d

Young pod linear, straight or slightly curved, ca. 15 X 1 mm, densely strigose with the hairs k spreading at the tips. Seeds not known.

Fig. 1.

Distribution and habitat. The species is known only from the easternmost comer of Ethiopia in the Ogaden (Fig. 7A). It occurs in open plains with sparsely scattered Acacia at about 550 m alt. The ground cover is domi- nated by small shrublets and on the type locality I. eremophila forms a high proportion of coverage to- gether with I. ogadensis Gillett, another endemic of this area.

Taxonomic remarks. I. eremophila with its pubescent corolla, k erect fruiting pedicels and fruits, short calyx and 1-veined stipules clearly belongs to subsect. Dis- sitij7orae (Bak.) Gillett of subgen. Indigofera. It seems closest related to I. vohemarensis Baill., a widespread species in E Africa from Ethiopia southwards to Mozambique and Madagascar. In Ethiopia I. vohe- marensis is known from Eritrea, Tigray, Shoa, Harerghe, Bale and Sidamo Regions and grows at medium altitudes (1350-2000 m) in grassland and woodland. The distance between the locality for I. eremophila and the nearest known locality of I , vohe- marensis (near Harer) is about 500 km. The most con- spicuous diagnostic character of I. eremophila is its many-flowered racemes, but the species differs from I. vohemarensis also in several other respects. The main differences are summarized in Tab. 1.

I. mooneyi "hub sp. nov. Type: Mooney 5893, Ethiopia, Keffa, Jimma, 7 Oct 1954 (K holot ype).

Fig. 1. Indigofera eremophila. - A: Flowering branch, x 1.5. - B: Calyx, 9. - E: Standard, flattened out, x 4.5. - F Wing, x 4.5. - G: Keel, X 4.5. From Gilbert 2090.

4.5. - c: Young 4.5, - D: Anther, Species nova ab I. atricipiti Hook. f. indumento pilis rnulticellularibus glandulosis fere destituto et inflores- centiis satis laxis floribus mod0 ca. 10-20 differt.

Tab. 1. Differences between Indigofera eremophila and I. vohemarensb.

Characters I . eremophila I. vohernarensis

Indumentum silvery strigose Smell Leaflets obovate, 3-5 in number Petiole 3-9 mm long Racemes

Calyx

probably not smelling of coumarin

10-25-flowered, the floriferous part much longer than the peduncle which is 2-12 mm long

2-2.5 mrn long, with the vexillar sinus much wider than the others

strigose but less densely so and not appearing silvery smelling of coumarin elliptic to cuneate-oblong, (3-)5-7(-9) in number 1-6 mm long 4-7-flowered, the floriferous part equalling or shorter than the peduncle which is 8-20 mm long

ca. 1.5 mm long, with the vexillar sinus not wider than the others

42

Annual or short-lived perennial, ca. 15-100 cm tall; all parts appressed strigose with biramous hairs, many of which are brown or black; glandular multicellular hairs practically absent, but sparse short multicellular hairs usually present on calyces, stipules, leaflet midveins and pods; young stems strigose with mixed white and black hairs. Leaves (3-)5-9-foliolate; rhachis 15-50 mm long including a petiole of 2-12 mm, prolonged 1.5-7 mm beyond the lateral leaflets, strigose with mixed white and black hairs; petiolules ca. 0.8 mm long; leaflets opposite, elliptic-oblong to narrowly obovate, 6-18 x 3-9 mm, the terminal usually slightly larger than the others, rounded and apiculate at the apex, rounded or broadly cuneate at the base, sparsely strigose with slen- der white hairs above, strigose with thicker white hairs and sparse brown or black hairs along midrib and mar- gins on the lower side; stipels absent, but a small in- conspicuous tuft of a few dark hairs often present at the

base of the petioles; stipules subulate, 2-3 mm long. Racemes fairly lax, ca. 10-20-flowered, the floriferous part ca. 2 4 cm long and about equalling the peduncle, with mixed white and dark hairs; bracts erect, 1.2-2.4 mm long, linear-lanceolate, with dark hairs, soon fall- ing; pedicels 1.2-1.6 mm long, ? spreading. Calyx densely brown or black strigose, deeply divided; lobes narrowly triangular with subulate tips, 1.6-2.6 mm long, the lowermost usually somewhat longer than the others. Corolla red; standard broadly ovate, ca. 4 X 3 mm, rounded and mucronulate at the apex, densely dark strigose on the back; wings ca. 3.8 X 1.2 mm, glabrous; keel ca. 4.4 mm long, acutely spurred at each side, not beaked, dark strigose on the outside near the apex. Stamens all fertile, 3.2-4 mm long; anthers ovate, ca. 0.5 mm long including the ca. 0.1 mm long acute apical appendage. Ovary strigose, 4-5-ovulate; style ca. 2.5 mm long, upcurved a little above the middle, glabr-

at! C

Fig. 2. Indigofera mooneyi. - A: Flowering branch,

Calyx, X 4.5. - D: Anther, x 9. - E: Standard, X 4.5. - F: Wing, X 4.5. - G: Keel, X 4.5. From Mooney 5893.

X 1.5. - B: Pod, X 4.5. - C:

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ous except at the base; stigma capitate, terminal. Pod spreading or erecto-patent, subcylindrical, straight or slightly curved, 5-8 x 1.6 mm, strigose with white and brown hairs, endocarp not spotted. Seeds 2-5, dull yel- lowish or greyish, ca. 1.3 x 1.1 X 0.8 mm, smooth.

Fig. 2.

Distribution and habitat. The species is known only from the highlands of SW Ethiopia (Fig. 7A), where it grows in grassland and scrub at 1650-2000 m alt.

Taxonomic remarks. The type collection of I. mooneyi, as well as QuarrC 1091 from Katanga, was mentioned by Gillett (1958: 80) under I. atriceps Hook. f. ssp. rhodesiaca Gillett in subsect. Atratae Gillett, but the question of their taxonomic status was left open. The material now available proves that the Ethiopian plant is a distinct taxon close to the extremely variable I. af- riceps. This is represented in SW Ethiopia by three subspecies, ssp. atriceps, ssp. setosissima (Harms) Gillett and ssp. kaessneri (Bak. f.) Gillett, all being very differ- ent from I. mooneyi. The most similar subspecies of I. atriceps instead seems to be ssp. rhodesiaca, from which I . mooneyi differs in the following characters: very sparse occurrence of multicellular hairs, 1-4-jugate leaves, usually longer petioles, and more long-pedun- culate racemes. 1. mooneyi is thus fairly easily distin- guished from each of the subspecies of I. atriceps, but when the total variation of this species is taken into consideration I. mooneyi seems to differ only in the very inconspicuous multicellular hairs and the fairly lax and few-flowered inflorescences. Although this is a rather weak distinction I prefer to treat the latter as a species rather than making it another subspecies of I. atriceps. If I. mooneyi is included in I. atriceps this species would be almost impossible to define and a number of other re- lated taxa now treated as distinct species would also have to be drawn into the complex. The collection QuarrC 1091 (BR, K), mentioned above, and some other collections from Katanga, which agree with it (de Witte 3491 BR and MaIaisse 9149 BR, C), cannot be included in I. mooneyi, however. They differ in having more short-pedunculate racemes, uniformly white hairs on stems and leaves, conspicuous tufts of dark hairs at the base of the petiolules, and 6-11 mm long, more dark-strigose pods. Cronquist (1954: 169) included with hesitation Quarr6 1091 and de Witte 3491 in I. shinyangensis Milne-Redh., but probably they represent a still undescribed species, which on account of its partly dark indumentum seems more closely related to I. atri- ceps, I . glaucifolium Cronquist and I. mooneyi than to I . shinyangensis. I . mooneyi is named after the English- man H. F. Mooney, whose extensive collections from Ethiopia form the nucleus of the national herbarium in Addis Abeba.

Collections besides the type. Ethiopia. Wellega, Sajo (Dem- bidolo), Jul 1938, Benedetto 177 (FI'). Shoa, Guder, 15 and 16 Oct 1937, Piovano 112 and 221 (both FT); near Baco, 9"08'N, 37"05'E, Sept 1969, Mogk 270 (EA, K). Keffa, Giren, 7'42'N, 36'53'E, 5 Dec 1972, Friis et al. 1567 (C, K); 90 km on Jimma-Addis Abeba road, 3 Sept 1974, Bos 8652 (WAG); 10 km W of Jimma, 19 Nov 1955, Stewart C-25 (BM, EA); Ghelcam, ca. 12 km SE of Maji, 15 Oct 1957, Smeds sen. (H). Sidamo, 12 km S of Soddu, ca. 6'49'N, 37"50'E, 5 Sept 1975, Gilbert, Thulin and Aweke 556 (ETH, K, MO, UPS, WAG).

I. boranica Thulin sp. nov. Type: Gilbert & Thulin 1517, Kenya, Mandera Distr., 54 km on the Ramu-Malka Man road, ca. 4"10'N, 40"48'E, 6 May 1978 (UPS holotype, C, EA, K, MO, WAG isotypes).

Species nova ab I. lupatana Bak. f. floribus multo majoribus staminibus 7-8 mm longis differt.

Slender erect shrublet up to 1-2 m tall; bark on old stems dark purple with circular lenticels; young branchlets strigose, hairs appressed or slightly spreading at the tips, white, sometimes intermingled with scattered short multicellular dark hairs. Leaves pinnately 5-9- foliolate; rhachis 2-4.5 cm long including a petiole of 0.5-1.3 cm; petiolules 0.8-1.2 mm long; leaflets elliptic to obovate, 4-15 x 2.5-10 mm, rounded to emarginate at the apex, rounded to broadly cuneate at the base, strigose on both surfaces with appressed or somewhat spreading hairs; stipels absent but a small tuft of short dark hairs present at the base of the petiolules; stipules triangular with k attenuate tips, sometimes with k scarious margins, 1.5-2.5 mm long. Racemes fairly dense, ca. l0-25-flowered, 3-7.5 cm long, including a peduncle of 0.5-2 cm, f sparsely strigose and with scattered multicellular dark hairs; bracts spreading, narrowly ovate, ca. 1.2 mm long, caducous or subper- sistent; pedicels 1.5-2 mm long, becoming reflexed in fruit. Calyx 3.5-5 mm long, strigose, deeply divided into very narrowly triangular to almost setaceous lobes, the lowermost usually somewhat longer than the others, the sinuses between the 3 lower lobes much narrower than the others. Standard dull greenish red on the back, red on the front, broadly ovate, ca. 8-9 X 7-8 mm, truncate to emarginate at the apex, truncate at the base, white strigose or occasionally glabrous on the outside, densely puberulous on the margin and on a narrow marginal zone of the inner surface; wings red, ca. 7-9 X 2.5-3.5 mm, ciliate at the apex and along the upper margin particularly near the base, shortly clawed; keel greenish, red at the tip, ca. 7-9 mm long, acutely spurred at each side, not beaked, pubescent at the apex and along the upper margin, with claws 1.5-2 mm long. Stamens all fertile, 7-8 mm long; anthers ovate, 0 . 6 4 . 8 mm long including the 0 . 1 4 . 2 mm long acute apical appendage. Ovary strigulose, linear, many-ovulate; style ca. 2.5-3.5

44

L

Fig. 3. Indigofera boranica. -A: Flowering branch, X 1.5. - B: Calyx, x 4.5. - C: Young pod, X 4.5. - D: Anther, X 9. - E: Standard, flattened out, X 4.5. - F: Wing, X 4.5. - G: Keel, X 4.5. From Gilbert & Thulin 1517.

mm long, curved upwards or backwards near the middle, glabrous; stigma capitate, terminal. Young pod linear, straight, somewhat flattened, ca. 15 X 1 mm, white strigose. Seeds not known.

Fig. 3.

Distribution and habitat. The species is known only from SE Ethiopia and NE Kenya (Fig. 7A). It grows in Acacia, Commiphora bushland on limestone (Ash 2434 is said to be from sandstone) at 780-1450 m alt.

Taxonomic remarks. The Ethiopian plants have more

appressed indumentum and somewhat broader calyx- lobes than the type, but otherwise agree with those from Kenya. One of the individuals of Ash 2434 has a glab- rous standard back, lacking the biramous hairs, but where the minute pubescence along the margins is pre- sent.

I . boranica seems to be best placed in subsect. Tinctoriae (Bak.) Gillett of subgen. Indigofera and is probably most closely related to I . lupatana Bak. f. This is a widespread species in arid areas of eastern Africa, from S Ethiopia in the north to Transvaal in the south. Like I . boranica it is a slender shrub with normally 5-9- foliolate leaves. I. boranica differs most markedly in its much larger flowers with stamens 7-8 mm long (ca. 3 mm in I . lupatana). The dark purple stems also seem to be characteristic of I . boranica. I . lupatana has charac- teristic, distinctly tetragonal, almost winged pods, but as at present only young pods are known in I . boranica no comparison can be made in this respect.

Collections besides the type. Ethiopia. Sidamo, 7 5 km on the Negele-Filtu road, 5"20'N, 39"30'E, 16 Apr 1974, Ash 2434 (Kj; near Siro waterholes ca. 30 km NW of Filtu, ca. S017'N, 40 27'E, 12 May 1980, Thulin, Hunde & Tadesse 3.597 (EA, ETH, FT, K, UPS); 49 km on the Negele-Filtu road, ca. 5"13'N, 40"00'E, 12 May 1980, Thulin, Hunde & Tadesse 3629 (ETH, UPS).

I. cavallii Chiov. Kenya. Mandera Distr., 30 km on the Ramu-Malka Mari road, ca. 4"04'N, 40"59'E, 6 May 1978, Gilbert & Thulin 1530 (BR, C, E, EA, lT, G, K, KRA, MO, P, PRE, UPS, WAG, Z).

I . cavallii (subsect. Tinctoriae) has previously been known only from the type, Paoli 922 bis (FT) from Aden-Caboba (Edain Caboba) in S Somalia (cf. Chiovenda 1915: 380; Baker 1926: 155; Cufodontis 1955: 263; Gillett 1958: 105). The new find was made along a watercourse and at the roadside in a limestone valley just S of Daua River at ca. 400 m altitude. The vegetation in the area is an Acacia-Commiphora bush- land with scattered trees of Sterculia, Terminalia, etc. The locality is about 200 km NW of the type locality (Fig. 7B). The species was also seen in large quantities in places along the road eastwards towards Ramu.

I. gyrata Thulin sp. nov. Type: Gilbert & Thulin 1372, Kenya, Mandera Distr., 4 km on the Mandera-Ramu road, ca. 3"56'N, 41"50'E, 3 May 1978 (UPS holotype, BR, C, EA, K, KRA, MO, WAG isotypes).

Species nova ab I . wajirensi Gillett leguminibus valde curvatis vel gyratis et pedicellis 2-3 mm longis differt.

Perennial herb, 10-30 cm tall with spreading, some- times almost prostrate branches, covered on all parts

45

Fig. 4. Indigofera gyrata. - A: Flowering branch, X 1.5. - B: Part of fruiting raceme, X 1.5. - C: Calyx, X 4.5. - D: Ovary, ~ 4 . 5 . - E: Anther with basal scale, x 9. - F: Standard, x 4.5. - G: Wing, x 4.5. - H: Keel, x 4.5. From Gilbert & Thulin 1372.

with stiff spreading biramous hairs, which are mostly white but yellowish on the young shoots. Leaves pin- nately 3-5-foliolate, the lower ones often 1-foliolate; rhachis up to 25 mm long including a petiole of 10-20 mm, in 3-foliolate leaves prolonged up to 7 mm beyond the lateral leaflets, in 5-foliolate leaves not prolonged beyond the distal lateral leaflets; petiolules ca. 0.5 mm long; leaflets elliptic, the terminal 12-40 X 4-10 mm, the lateral ones smaller, opposite, rounded and apicu- late at the apex, cuneate at the base, clothed with

spreading hairs on both surfaces ; stipels absent; stipules lanceolate-attenuate, spreading, 5-10 X 0.6-1.2 mm. Racemes lax, many-flowered, up to 15 cm long in the fruiting stage, including a peduncle of up to 3 cm; bracts spreading, lanceolate, 1-2.5 mm long, persistent; pedicels 2-3 mm long, first erecto-patent, in fruit standing at t right angles to the axis of the raceme. Calyx 1.8-2.4 mm long, divided to about the middle into narrow lobes. Corolla glabrous, pink, or occasionally white; standard broadly orbicular, ca. 5 X 6 mm, broadly rounded at the apex, abruptly narrowing into a short claw at the base; wings ca. 4.8 x 1.2 mm, shortly clawed; keel ca. 4.8 mm long including a claw of ca. 1.2 mm, shortly,beaked, not spurred. Stamens ca. 2.8-3.6 mm long; vexillar stamen without anther, the others with anthers ca. 0.4 mm long, broadly elliptic, with a minute hyaline appendage at the apex, and at the base with hyaline scales ca. 0.2 mm long in the 4 shorter stamens and ca. 0.1 mm in the 5 longer stamens. Ovary pubescent; style flattened at the base, 1-1.5 mm long, glabrous; stigma discoid, inflexed, ca. 0.4 mm in diameter. Pod strongly curved or spirally coiled, flat- tened, ca. 20-30 X 1.6 mm, spreading pubescent, ca. 20-25-seeded, endocarp not spotted. Mature seeds not seen.

Fig. 4.

Distribution and habitat. The species is known only from the NE corner of Kenya (Fig. 7C), but almost certainly occurs also in Ethiopia and Somalia as the present col- lections were made within a few kilometers from the borders of these countries. It is locally common in Acacia-Commiphora deciduous bushland on red sandy soil or on limestone at 290-780 m altitude.

Taxonomic remarks. I . gyrata belongs to the very natural group of species which is now usually treated as subgen. Microchuris (Benth.) Gillett (1958: 127). The group which was formerly given generic rank, is characterized mainly by having glabrous corolla, keel without spurs, vexillar stamen nearly always without an anther, and anthers, at least those of the 4 shorter sta- mens, with hyaline scales at the base. The group com- prises some species more or less restricted to the de- ciduous bushlands of E and S Ethiopia and NE Kenya, such as I. stipulosa Chiov., I . cufodontii Chiov. and I . wajirensis Gillett. It i s also with these species that I. gyrutu is most closely related, although it differs mar- kedly from them all in the strongly curved or coiled pods. It also differs from I. stipulosa and 1. cufodontii in the pinnately (1-)3-5-foliolate leaves (leaves 1 -folio- late in I. stipulosa and digitately 3-foliolate in I. cufodontii). The remaining species, I. wajirensis, seems to be that which is most closely allied to I. gyrata. It has similar leaves to this species, but has almost straight pods on 4-5 mm long pedicels. I. wajirensis is only known from an area of flat bushland on deep sand near

46

Wajir, some 280 km SW of the known localities of 1. gyrata.

Collection besides the type. Kenya. Mandera Distr., 54 km on the Ramu-Malka Mari road, ca. 4"10'N, 40"48'E, 6 May 1978,Gilbert &Thulin 1515 (BR, C,E, EA, G, K, KRA, MO, P, PRE, UPS, WAG).

1. ammophila Thulin sp. nov. Type: Gilbert & Thulin 1672, Kenya, Mandera Distr., 12 km S of El Wak on Wajir road, ca. 2"44'N, 40"55'E, 11 May 1978 (UPS holotype, BR, C, EA, K, KRA, MO, WAG isotypes).

Species nova a b I . wajirensi Gillett staminibus 4-5 mm longis, leguminibus ca. 2.5 mm latis apicem versus haud curvatis, pedunculis racemi parte florifera circa aequantibus et stipulis 3 4 mm longis differt.

Perennial, slightly woody, up to 0.5 m tall, with spread- ing branches, covered on all parts with spreading biramous hairs, which are mostly white but yellowish on the young shoots. Leaves pinnately 3-foliolate, the lower ones sometimes 1-foliolate; petiole 3-23 mm long; rhachis prolonged 2 4 mm beyond the lateral leaflets; petiolules ca. 0.5 mm long; leaflets rather tough and hard in texture, elliptic-oblong; terminal leaflet 9-21 x 4-8 mm, lateral ones somewhat smaller, opposite, rounded and apiculate at the apex, cuneate at the base, pubescent with spreading hairs on both sur- faces; venation prominent beneath; stipels absent; stipules lanceolate-attenuate, spreading, ca. 34.5 x 0.4-0.7 mm. Racemes lax, ca. 10-20-flowered, up to 14 cm long in fruit, including a peduncle of up to 7 cm; bracts spreading, lanceolate, 1.2-2 mm long, persistent; pedicels 5-8 mm long, first erecto-patent, in fruit some- what reflexed or standing at ? right angles to the axis of

Fig. 5. Indigofera ammophila. - A: Flowering branch, x 1.5. - B: Pod, X 1.5. - C: Calyx, X 4.5. - D: Ovary, X 4.5. - E: Anther with basal scale, X 9. - F: Standard, X 4.5. - G: Wing, X 4.5. - H: Keel, X 4.5. From Gilbert & Thulin 1672.

G: Wing, X 4.5. - H: Keel, X 4.5. From Gilbert & Thulin 1672.

47

Tab. 2. Differences between Indigofera ammophila and 1. wajirensis.

Characters I. ammophila 1. wajirensis

Stipules 34 .5 mm long Peduncles

Pods

Stamens 4-5 mm long ca. 3 mm long Habit

up to 7 mm long, at least some more than 5 mm long up to 3(4) cm long, half or less of the length of the floriferous part of raceme 1-1.5 mm wide, slightly upcurved at the apex

stems herbaceous from a somewhat woody taproot; leaf texture thin and membranous

up to 7 cm long, about as long as floriferous part of raceme ca. 2.5 mm wide, straight

stems slightly woody from a woody base; leaf texture rather tough and hard

the raceme. Calyx ca. 2.8 mm long, divided to about the middle into narrowly triangular lobes. Corolla glabrous, pale red; standard broadly orbicular, ca. 6.5 X 6.5 mm, broadly rounded at the apex, abruptly narrowing into a short claw at the base; wings ca. 6.5 X 1.6 mm, shortly clawed; keel ca. 6.5 mm long, including a claw of ca. 1.5 mm, scarcely beaked, not spurred. Stamens 4-5 mm long; vexillar stamen without anther, the others with anthers ca. 0.5 mm long, broadly elliptic, with a minute hyaline appendage at the apex, and at the base with hyaline scales ca. 0.2 mm long on the 4 shorter stamens and ca. 0.1 mm on the 5 longer stamens. Ovary pubes- cent; style flattened at the base, ca. 1.5 mm long, glabr- ous; stigma discoid, inflexed, ca. 0.5 mm in diameter. Pod straight, flattened, ca. 30-55 X 2.5 mm, spreading pubescent, ca. 15-25-seeded, endocarp not spotted. Seeds rectangular-reniform, ca. 1.6 X 1 mm, minutely warty with the warts arranged in f longitudinal lines.

Fig. 5 .

Distribution and habitat. The species is known only from a single locality in the NE corner of Kenya close to the Somalian border (Fig. 7C). It is quite common in an area of open flat bushland on deep sandy soil with widely spaced trees of Delonix, Acacia and Com- miphora at ca. 420 m alt. Endostemon ctenoneurus R. Harley 1980: 547 (Labiatae) has been described from the same locality.

Taxonomic remarks. Like I . gyrata, I. ammophila is closely allied to 1. wajirensis in subgen. Microcharis with which it agrees in having pinnate leaves and straight pods. Still, I. ammophila differs in many respects from 1. wajirensis. The main differences between the two species are summarized in Tab. 2.

I. cana Thulin sp. nov. Type: Mooney 9620, Ethiopia, Wello Region, below Bati on Assab road, ll"lO'N, 39"55'E, 18 Sept 1962 (ETH holotype, UPS isotype).

Species nova ab I . stipulosa Chiov. foliolis circa duplo longioribus quam latis, stipulis 1 4 mm longis, pedun-

culis 1 . 5 4 mm longis, pedicellis usque ad 3 mm longis et floribus minoribus staminibus 3-3.5 mm longis dif- fert.

Perennial much-branched herb with prostrate to as- cending, rather woody, k zigzag stems up to at least 20 cm long, densely covered on all parts with f appressed to somewhat spreading biramous hairs and appearing greyish white or, on the youngest shoots, yellowish. Leaves 1-foliolate; petiole 1-6 mm long; petiolules ca. 0.5 mm long; leaflets rather tough and hard in texture, narrowly obovate to elliptic, 8-25 X 3-12 mm, sub- acute at the apex, cuneate at the base, indumentum on both surfaces dense, greyish white, closely appressed; stipules linear, spreading to recurved, 1 4 mm long. Racemes fairly dense, ca. 1030-flowered, 10-50 mm long, including a peduncle of 1.5-6 mm; bracts spread- ing, lanceolate, 1-1.6 mm long, persistent; pedicels 1-1.5 mm long, first erecto-patent, in fruit elongating to

h

Fig. 6. Indigofera cana. - A: Portion of flowering branch, x 1.5. -B: Ovary, x 4.5. -C: Anther with basal scale, X 9. - D: Calyx, x 4.5. -E: Standard, X 4.5. -F: Wing, X 4.5. -G: Keel, x 4.5. From Mooney 9620.

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Fig. 7. Known distributions of some species of lndigofera. - A: 1. eremophila (W), 1. mooneyi (0 ) and 1. boranica (*). - B: 1. cavallii. - C: 1. gyrara (O) , 1. ammophila (W) and 1. cana (*).

ca. 1.5-3 mm and standing at k right angles to the axis of the raceme. Calyx 1.5-2.5 mm long, divided almost to the middle into narrowly triangular lobes. Corolla glabrous, pale lilac-red to bright red; standard subor- bicular, 4-4.5 x 4-4.5 mm, broadly rounded at the apex, abruptly narrowing into a short claw at the base; wings ca. 4 X 1 mm, auriculate, shortly clawed; keel ca. 4.5 mm long, including a claw of ca. 1.5 mm, scarcely beaked, nor spurred. Stamens 3-3.5 mm long; vexillar stamen without anther, the others with anthers 0.3-0.4 mm long, broadly elliptic, with a minute hyaline appen- dage at the apex, and with hyaline scales at the base; the latter 0.15-0.2 mm long on the 4 shorter stamens and slightly shorter on the 5 longer stamens. Ovary pubes- cent; style ca. 1.5 mm long, glabrous; stigma discoid, inflexed, 0.3-0.4 mm in diameter. Pod straight or slightly curved, ca. (7-)15-20 x 1.5 mm, appressed strigose, ca. 3-9-seeded, endocarp not spotted. Mature seeds not seen.

Fig. 6.

Distribution and habitat. The species is known only from the escarpment west of the Danakil Desert in the Wello Region in Ethiopia (Fig. 7C). It grows in Acacia scrub on stony or rocky ground at 1200-1800 m alt.

Taxonomic remarks. The two collections known of I. cana are rather different in habit. W. de Wilde et al. 7348 represents prostrate, dwarfed plants, while Mooney 9620 is more lush with ascending stems. Un- doubtedly these differences are environmentally con- ditioned, the first-mentioned collection being from an “exposed rocky place”. The species belongs to subgen. Microcharis and its closest affinities seem to be with I. stipulosa Chiov., which is likewise endemic in Ethiopia

Tab. 3. Differences between lndigofera cana and 1. stipulosa.

Characters 1. cana 1 sripulosa

Leaflets ca. twice as long as more than three wide times as long as

wide Stipules 1 4 mm long 6-11 mm long Peduncles 1.5-6 mrn long 20-150 mm long

Pedicels up to 3 mm long in 5-10 mm long in fruit fruit

Stamens 3-3.5 mm long ca. 4 mm long

and known with certainty only from Sidamo Region. Gillett (1958: 127f) stated that the petioles in I. stipulosa are not separated from the lamina by a joint. This is not in accordance with my own observations. In both I. stipulosa and I . cana there is a distinct joint between petiole and lamina. Diagnostic to I. cana are its broader leaflets about twice as long as wide, the shorter stipules, the shorter peduncles, the denser and more many-flowered inflorescences, the shorter pedicels, the flowers which are smaller in all parts, and the denser and more silvery-grey indumentum (see Tab. 3).

There is one problematic collection, Gilbert 2028 (ETH, K) from Harerghe Region, 48 km S of Jijiga. This agrees with I. stipulosa in most respects but has more closely appressed indumentum and narrower, only 3-7 mm long stipules, and thus somewhat approaches 1. cana. The collection may represent a still undescribed species closely related to I. stipulosa but may also prove to be merely a form of this species. In the latter case the difference in stipule length given in Tab. 3 would be less pronounced.

4 Nord. J. Bot. 2(1) 1982 49

Collection besides rhe rype. Ethiopia. Wello Region, ca. 10 km References Baker, E. G. 1926. The Leguminosae of tropical Africa 1. -

Ghent. Chiovenda, E. 1915. Plantae novae vel minus cognitae a re-

gione aetiopica. - Ann. di Bot. 13: 371410. Cronquist, A. 1954. Indigofera. - In: Flore du Congo Belge et

Acknowledgements - 1 am indebted to the Directors and du Ruanda-Urundi 5: 117-173. Institut National pour Curators of the Herbaria in BM, C, ETH, FT, H, K and WAG I’fitude Agronomique du Congo Belge. Bruxelles. for working facilities and loan of material. Financial support Cufodontis, G. 1955. Enumeratio plantarum Aethiopiae for the study has been given by the Swedish Natural Science Spermatophyta (sequentia). - Bull. Jard. Bot. fitat. 25,

Gillett, J. B. 1958. Indigofera (Microcharis) in tropical Africa with the related genera Cyamopsis and Rhynchorropis. - Kew Bull. Add. Series 1.

- 1971. Indigofera. -In: Milne-Redhead, E. & Polhill, R. M. (eds.), Flora of Tropical East Africa. Crown Agents for Oversea Governmepts and Administrations. London.

Harley, R. M. 1980. A new Endosremon (Labiatae) in Kenya. - Kew Bull. 34: 547-549.

Of Bati’ 22 Jul 1965’ w* de Wilde et al‘ 7348 (WAG)’

Research Council. Suppl.

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