Notes on Acacia species from north-east Tropical Africa

Information relating to a number of miscellaneous from north-east tropical Africa is presented. A lthough an excellent account o f the Acacia species o f tropical east Africa was published some years ago (Brenan in FI. Trop. E. Afr. Legum.-Mimos., 1959), doubt still surrounds the identity o f a number of species described by Emilio Chiovenda from north­ east tropical Africa, particularly from the Somali Republic. Through the kindness o f Prof. Dr C. H. Steinberg, Conservator of the H erbarium Universitatis Florentinae, the type specimens o f most o f these species were received on loan. Those decisions requiring explanation in print form the subject o f this paper. ACACIA BRICCHETTIANA Chiov. Robecchi Bricchetti 533 from the Ogaden, Somali Republic, the type specimen of A. bricchettiana Chiov., in Ann. Bot., Roma 13: 396 (1915), consists o f two flowering twigs. The older twigs of the previous season are reddishto dark brown, sparingly puberulous and with numerous, somewhat transversely-elongated lenticels, while those of the current season are reddishbrown, with fewer lenticels but more densely puberulous. The epidermis has split longitudinally in places to reveal a yellowish inner layer. The paired stipular spines are slender and up to 4 ,5 cm long. The leaves are fairly densely puberulous throughout, with minute, scattered glands along the rhachis, up to 11 pinnae pairs and 10-17 leaflet pairs per pinna. The leaflets are up to 5 x 1,3 mm, the lower surface is paler than the upper, the margins have conspicuous cilia, while scattered hairs sometimes also occur on the lower surface. The midrib (and occasionally a few of the lateral nerves) is conspicuous and slightly raised on the lower surface. The peduncles are very short, up to 6 mm long, densely pubescent and glandular; the involucel is basal. The calyces and corollas appear to be reddish or purple, but this impression may be the result o f the drying process. The calyces are up to 2 mm long and are glabrous or subglabrous except for the lobes which are pubescent. Likewise, the corollas, which are ± 3 mm long, are glabrous except for the lobes which are pubescent. The corolla-Iobes are up to 1,2 mm long, so the corolla is divided almost down to the calyx. As the description o f Acacia gloveri Gilliland in Kew Bull. 6: 139, t.4 (1951) seemed very close to that o f A. bricchettiana, Glover & Gilliland 388, the holotype of A. gloveri from the Ogaden, Somali Republic, was compared with Bricchetti 533. Vegetatively Glover & Gilliland 388 is a good match of Bricchetti 533 agreeing in that the older twig is dark ± purplish-brown, transversely lenticellate and with the epidermis peeling slightly to reveal a yellowish inner layer, while the younger twig is reddish-brown and densely pube­ rulous. Similarly, the leaves agree in being fairly densely puberulous throughout and glandular, and the leaflets are o f a similar size although some in Glover & Gilliland 388 are marginally larger than those o f Bricchetti 533. Leaflet colour, venation and pubesscence in Glover & Gilliland 388 matches that of Bricchetti 533. * Botanical Research Institute, Department o f Agricultural Technical Services, Private Bag XI01, Pretoria. 1 7 7 4 9 -7 Acacia species described by E. Chiovenda Although Glover & Gilliland 388 is a fruiting speci­ men, the remains o f an inflorescence is visible on the holotype in the Kew Herbarium and also on the specimen in the carpological collection. The peduncle is puberulous and the remains o f a basal involucel are evident. The remains o f dark-coloured spatulate bracts, pubescent at the apex, are visible on the inflorescence and these agree well with those on the flowering specimen o f Bricchetti 533. In view o f this general agreement it seems certain that A. gloveri and A. bricchettiana are conspecific. Consequently, I now reduce A. gloveri to synonymy under A. bricchettiana, the earlier name. Acacia bricchettiana Chiov. in Ann. Bot., Roma 13: 396 (1915). Type: Somali Republic, Ogaden, Rob?cchi Bricchetti 533 (FI, holo.!). A. gloveri Gilliland in Kew Bull. 6: 139, t.4 (1951), synon, nov. Type: Somali Republic, Ogaden, between Wardere and Walwal, Glover and Gilliland 388 (K, holo.!; BM, iso.!). ACACIA CHEILANTHIFOLIA CHIOV. Chiovenda, FI. Somala 1: 168, t. xvii, fig. 1 (1929), based his description of A. cheilanthifolia on five syntypes from the Somali Republic, namely, Puccioni & Stefanini 479 (531), 509 (562), 663 (727), 762 (843) and 1010 (1115). O f the five syntypes, only one, namely Puccioni & Stefanini 663, carries both flowers and pods. The following description is based on Puccioni & Stefanini 663 and any dimensions recorded other than those from this specimen are placed in parenthesis. The bark on the older twigs is ashen to greyishbrown, often with a somewhat mottled effect, flaking off here and there to reveal a yellowish-brown inner layer, while the young branchlets are reddish-brown and sparingly puberulous. The prickles are in threes near the nodes, typically with the two laterals pointing upwards and the median one pointing downward. However, there is some variation in the degree of curvature of the prickles and often they are ± straight and spreading. In Puccioni & Stefanini 1010 and, to a lesser extent and only in some instances, in Puccioni & Stefanini 479 an 762, the median prickle also points upwards so that all three prickles point upwards. The prickles are up to 6 (12) mm long. The leaves are small. The petiole is up to 6 mm long, with a large gland up to 2 mm long, elongated along the length of the petiole (sometimes rounded and only 0 ,5 mm in diameter), glabrous to sparingly puberulous. The rhachis is up to 1,5 (2,4) cm long, glabrous to sparingly puberulous, with recurved prickles on the lower surface and with a fairly large discoid gland at the junction o f the top 1-2 pinnae pairs. The pinnae are in (3-) 6 pairs and the rhachillae are up to 4(7) mm long and are without a terminal, recurved prickle. The leaflets are in 3-4 pairs per pinna, 1,5-2(5) X 1(2.5) mm, oblong to elliptic or rotund-ovate or obovateoblong, glabrous throughout. The inflorescence axes are glabrous or subglabrous and up to 4 cm long. The flowers are sessile and the calyx and corolla are glabrous throughout. The pods are yellowish-brown, 3-4(4,5) x 1 cm, straightish, rounded or m ucronate apically, flattened, dehiscent* venose and densely puberulous throughout. 300 NOTES ON ACACIA SPECIES FROM NO RTH -EAST TROPICAL AFRICA Puccioni & Stefanini 695 (769), the type specimen of A. cheilanthifolia var. hirtella Chiov., differs from typical A. cheilanthifolia in tha t the young stems, petioles, rhachides, rhachillae, leaflets, inflorescence axes and calyces are densely puberulous, and in that it

The leaflets are up to 5 x 1,3 mm, the lower surface is paler than the upper, the m argins have conspicuous cilia, while scattered hairs sometimes also occur on the lower surface. The m idrib (and occasionally a few o f the lateral nerves) is conspicuous and slightly raised on the lower surface.
The peduncles are very short, up to 6 mm long, densely pubescent and glandular; the involucel is basal. The calyces and corollas appear to be reddish or purple, but this impression may be the result o f the drying process. The calyces are up to 2 mm long and are glabrous or subglabrous except for the lobes which are pubescent. Likewise, the corollas, which are ± 3 mm long, are glabrous except for the lobes which are pubescent. The corolla-Iobes are up to 1,2 mm long, so the corolla is divided alm ost down to the calyx.
As the description o f Acacia gloveri Gilliland in Kew Bull. 6: 139, t.4 (1951) seemed very close to that o f A. bricchettiana, Glover & Gilliland 388, the holotype o f A. gloveri from the Ogaden, Somali Republic, was com pared with Bricchetti 533. Vegetatively Glover & Gilliland 388 is a good m atch o f Bricchetti 533 agreeing in that the older twig is dark ± purplish-brow n, transversely lenticellate and with the epiderm is peeling slightly to reveal a yellowish inner layer, while the younger twig is reddish-brown and densely pube rulous. Similarly, the leaves agree in being fairly densely puberulous throughout and glandular, and the leaflets are o f a similar size although some in Glover & Gilliland 388 are m arginally larger than those o f Bricchetti 533. Leaflet colour, venation and pubesscence in Glover & Gilliland 388 matches that of Bricchetti 533.
A lthough Glover & Gilliland 388 is a fruiting speci men, the rem ains o f an inflorescence is visible on the holotype in the Kew H erbarium and also on the specimen in the carpological collection. The peduncle is puberulous and the rem ains o f a basal involucel are evident. The remains o f dark-coloured spatulate bracts, pubescent at the apex, are visible on the inflorescence and these agree well with those on the flowering specimen o f Bricchetti 533.
In view o f this general agreem ent it seems certain th at A. gloveri and A. bricchettiana are conspecific. Consequently, I now reduce A. gloveri to synonymy under A. bricchettiana, the earlier name.
Acacia bricchettiana Chiov. in Ann. Bot., Rom a 13: 396 (1915). Type: Somali Republic, Ogaden, Rob?cchi Bricchetti 533 (FI, holo.!). Chiovenda, FI. Som ala 1: 168, t. xvii, fig. 1 (1929 The bark on the older twigs is ashen to greyishbrown, often with a som ew hat m ottled effect, flaking off here and there to reveal a yellowish-brown inner layer, while the young branchlets are reddish-brow n and sparingly puberulous. The prickles are in threes near the nodes, typically with the two laterals pointing upwards and the median one pointing downward. However, there is some variation in the degree o f curvature o f the prickles and often they are ± straight and spreading. In Puccioni & Stefanini 1010 and, to a lesser extent and only in some instances, in Puccioni & Stefanini 479 an 762, the median prickle also points upw ards so th at all three prickles point upwards. The prickles are up to 6 (12) mm long.

A. gloveri
The leaves are small. The petiole is up to 6 mm long, with a large gland up to 2 mm long, elongated along the length o f the petiole (sometimes rounded and only 0 ,5 mm in diam eter), glabrous to sparingly puberulous. The rhachis is up to 1,5 (2,4) cm long, glabrous to sparingly puberulous, with recurved prickles on the lower surface and with a fairly large discoid gland at the junction o f the top 1-2 pinnae pairs. The pinnae are in (3-) 6 pairs and the rhachillae are up to 4(7) mm long and are w ithout a term inal, recurved prickle. The leaflets are in 3-4 pairs per pinna, 1,5-2(5) X 1(2.5) mm, oblong to elliptic or rotund-ovate or obovateoblong, glabrous throughout.
The inflorescence axes are glabrous or subglabrous and up to 4 cm long. The flowers are sessile and the calyx and corolla are glabrous throughout. The pods are yellowish-brown, 3-4(4,5) x 1 cm, straightish, rounded or m ucronate apically, flattened, dehiscent* venose and densely puberulous throughout.
O n account o f the prickles in threes at the nodes, A. cheilanthifolia is clearly a m em ber o f the A. Senegal (L.) Willd. com plex. A. cheilanthifolia is a distinct species, differing from A. Senegal chiefly in having fewer leaflet pairs and sm aller pods. A. cheilanthifolia bears a superficial resem blance to some specimens o f A. somalensis Vatke, but the latter differs in having solitary prickles, usually 1 pinna pair per leaf, 2 leaflets per pinna and reddish-brow n pods 1 ,5 -1 ,7 cm wide.

AC ACIA C U FO D O N T II CHIOV.
Cufodontis 114 from Borana Prov., Ethiopia, the type specimen o f A. cufodontii Chiov. in Miss. Biol. Borana Racc. Bot. 4: 55, fig. 5 (1939), consists o f a single flowering twig. The greyish-brown, puberulous twig is arm ed with recurved prickles which occur singly near each node. The leaves have 2-4 pairs of pinnae and the petioles, rhachides and rhachillae are ± densely pubescent. The leaflets are in 9-13 pairs per pinna, up to 3 x 1 m m , and have conspicuous, spreading, m arginal cilia, while some leaflets are also pubescent on the lower surface. The inflorescence axes are ± densely pubescent, especially basally.
A. cufodontii clearly falls within the A. Senegal complex and is not specifically distinct from A. Senegal. W hether the prickles occur singly or in threes near a node in A. Senegal seems to be o f no significance as both arrangem ents m ay occur on one and the same shoot, although some gatherings may show all or nearly all the prickles arranged singly. A lthough A. cufodontii is not specifically distinct from A. Senegal, in the absence o f pods and adequate field notes, it is not possible to refer it to an existing variety o f A. Senegal with certainty. As the inflorescence axes are pubescent, A. cufodontii is not referable to var. Gorini 221 consists o f three twigs, the right-hand one o f which is in fruit while the two others are sterile. There are four pods on the specimen, one attached to a twig, two m ounted on the sheet and one in the capsule on the top left-hand corner o f the sheet. The twigs are yellowish-brown to greyish-white, glabrous o r subglabrous and lenticellate. The paired stipular spines are ± straight and up to 1,3 cm long. The leaves have up to 9 pinnae pairs, up to 13 leaflet pairs per pinna and the leaflets are up to 9 x 2 ,5 mm. The pods are chestnut-brow n, up to 11,8 x 1,4 cm, dehiscent, longitudinally striate and with flattened, ± wing-like margins.
Senni 435 from Lac B adana consists o f four alm ost leafless, flowering twigs. The peduncles are short, up to 6 mm long, pubescent, and the involucel is in the lower half o f the peduncle. The calyx and corolla are pubescent apically. The capsule m ounted above the collector's label contains a single old pod together with several inflorescences and leaf fragments.
Senni 449 from Obe, the third syntype, consists o f two flowering twigs, while the capsule m ounted in the bottom left-hand corner contains the rem ains o f two ancient pods and some seeds. A part from having fewer pinnae pairs and smaller leaflets, Senni 449 is essentially similar to Gorini 221.
As it is quite clear that A. gorinii is conspecific with A. nubica Benth., this opportunity is now taken o f reducing A. gorinii to synonymy.
Acacia nubica Benth. in H ook., Lond. J. Bot The bark on the old twigs is greyish-to purplishbrown, while that on the younger stems is yellowishto reddish-brow n. The prickles are in threes near the nodes, the two laterals pointing slightly upw ards or alm ost at right angles to the twig and the median one pointing dow nw ard. The only leaflets attached to the specimen are 1,2 mm wide. The inflorescence axes are sparingly pubescent basally and the pods are yellowish-brown, up to 7 x 2 ,2 cm, flattened, papery, venose, sparingly pubescent th roughout and distinctly rostrate apically.
There is no reason at all why A. oxyosprion should not be regarded as conspecific with A. Senegal (L.) Willd. The basally pubescent inflorescence axes and the pubescent pods with distinctly rostrate apices in A. oxyosprion var. oxyosprion, m atch those o f A. Senegal var. rostrata Brenan from southern Africa. There is, o f course, a large geographical discontinuity between the specimens with rostrate pods in the Somali Republic and those in southern Africa. The Somali material o f A. oxyosprion var. oxyosprion sometimes has slightly larger leaflets than is found in m aterial o f A. Senegal var. rostrata in southern Africa but, apart from this, there is little difference between the specimens and the differences do not appear worthy o f any form al taxonom ic recognition. U nfortunately, Guidotti 21, the type o f A. oxyosprion var. pubescens Chiov., has not been available for exam ination. From the description, var. pubescens apparently differs from var. oxyosprion solely in having a denser indum entum . If this is indeed the case then there is a possibility th at var. pubescens also belongs to the same taxon as A. Senegal var. rostrata. H ow ever, as it would be unwise to pass judgem ent on var. pubescens w ithout first exam ining the type specimen, no decision on its identity has been taken.
This uncertainty over the identity o f A. oxyosprion var. pubescens is em phasized, because if var. pubescens and A. Senegal var. rostrata prove to belong to the same taxon, then the varietal epithet "pubescens" has priority over " rostrata" and m ust be adopted for this taxon once the new com bination in A. Senegal has been effectively published (but see com m ents under A. Senegal var. pseudoglaucophylla). The type speci men o f A. oxyosprion var. pubescens is thought to be housed in the Instituto Botanico dell' U niversitá, M odena, but efforts to borrow the specimen on loan have failed. Paoli 875, which consists o f three twigs, is sim ilar to Paoli 1052 in having pubescent leaf-rhachides and inflorescence axes. The solitary young pod in the capsule m ounted in the lower left corner is pubescent th ro u g h o u t and distinctly acum inate apically. Once again, in the absence o f field notes, the specimen is hesitantly and provisionally referred to var. rostrata.

ACACIA P A R A D O X
The varietal epithet pseudoglaucophylla has priority over rostrata (and over A. oxyosprion var. pubescens) but, as the identity o f Paoli 875 and 1052 is not beyond all doubt, it would seem unwise at this stage to adopt the name pseudoglaucophylla for the speci mens with rostrate pods hitherto referred to var. rostrata. Clearly, better and much m ore m aterial with adequate field notes is required from north-east tropical A frica to establish the correct varietal epithet for the plants with distinctly rostrate pods.
Paoli 682, the sixth syntype, is a miserable, sterile specimen o f which the precise identity rem ains in doubt. The prickles near the nodes are solitary or in threes, and the leaves have one or two pinnae pairs.
To sum up, three o f the syntypes o f var. pseudo glaucophylla are referred to var. Senegal, two are hesitantly and provisionally referred to var. rostrata, and one cannot be identified.

ACACIA ST E FA N IN I CHIOV.
Paoli 844 from the Somali Republic, the type specimen o f A. stefanini Chiov. in Ann. Bot., Rom a 13: 395 (1915), consists o f three leafless, flowering twigs. The young branchlets are greyish-to reddishbrown, subglabrous to very shortly puberulous, and the paired, stipular spines are short and distinctly hooked. The peduncles are short, up to 6 mm long, fairly densely puberulous, and the involucel is at the base o f the peduncle, or a short distance above it. The calyces are cupular and m inute, up to 0 ,5 mm long. The corollas are 2 -2 ,5 mm long, th at is, at least four times as long as the calyces. The capsule in the bottom right-hand corner contains a small twig, flowers, and the rem ains o f one rhachilla. This rhachilla reveals th at the leaflets are in 7 pairs, ± 2 x 0 ,5 mm and slightly puberulous.
Paoli 844 is a fairly good m atch o f Hildebrandt 1394, the isotype o f A. reficiens W aw ra subsp. misera (Vatke) Brenan in the Kew herbarium . It agrees with Hildebrandt 1394 in the colour and indum entum o f the young branchlets, the short, hooked spines, the short, puberulous peduncles, the small, cupular calyces, and the tubular corolla which is ± 4 times as long as the calyx. Consequently, I have no hesitation in reducing A. stefanini to synonymy under A. reficiens subsp. misera.
Acacia reficiens Wawra subsp. misera ( Vatke) Brenan in Kew Bull. 12: 90 (1957 Some years after describing A. stefanini, Chiovenda, in FI. Som ala 2: 197 (1932), referred the specimens Senni 711 and 813 to this species and provided a description o f the pods. A pod o f Senni 813 is illustrated in Fig. 119. The pods were described as turgid and cylindrical with strongly convex valves. As the description o f the pods and the illustration are at variance with the pods o f typical A. reficiens subsp. misera, Senni 711 and 813 were borrow ed on loan from Florence.
Senni 711 and 813, which are both flowering speci mens, are referable to A. reficiens subsp. miser a. However, the capsule m ounted on the sheet o f Senni 813 contains eight old pods. All o f the pods have been extensively galled, which accounts for their atypical appearance and C hiovenda's description.

ACACIA U N ISPIN O SA (F lO R l) CHIOV.
W hen Fiori described A. asak (Forsk.) Willd. var. unispinosa in L 'Agric. Coloniale 5: 93, Fig. 67/3 (1911), he om itted to cite any specimens or to nom inate a type specimen, citing merely " Nel Sam har alia stazione di Mai Atal e U akiro (F )" . U nder the circum stances, all o f the specimens in FI collected prior to the date o f publication and determ ined by him as var. unispinosa, are regarded as syntypes.
A m ong the m aterial received on loan from Florence, were three specimens collected by Fiori and deter mined by him as " Acacia asak W. var The branchlets are greyish to purplish-grey or greyish-brown, glabrous or sparingly pubescent on the young extremities, and arm ed with a solitary recurved prickle near each node. All leaves have one pinna pair, sparingly puberulous petioles up to 7 mm long, rhachillae up to 1,5 cm long, and 4-7 pairs o f glabrous glaucous leaflets per pinna which are up to 6 x 2 ,5 mm. Some o f the leaflets are galled. The inflorescence axes are sparingly pubescent throughout or basally only and are up to 5 cm long. The calyces are glabrous or very sparsely puberulous. The pods are yellowish-brown, up to 4 ,8 X 1,1 cm, ± straight, glabrous or very sparingly pubescent, especially on the margins and near the stipe, venose and longitudinally dehiscent.
Two other specimens, namely, Baldrati 4147, 4148, were also determ ined by Fiori as var. unispinosa but, as they were collected subsequent to the publication o f var. unispinosa, they are o f lesser interest. They are both appalling specimens and their chief interest must surely be the num erous galls on the inflorescences and leaflets. The prickles on each o f the specimens are either solitary or else in threes near the nodes.
It is clear that var. unispinosa is specifically distinct from A. asak, as the latter has much larger leaves with 3-6 pinnae pairs, 6-17 pairs o f leaflets per pinna and usually larger pods. Var. unispinosa is also specifically distinct from A. Senegal Senni 822, however, clearly belongs to a different taxon. The prickles are in threes near the nodes, or solitary. The leaves have a spreading indum entum , 3-4 pinnae pairs, and each pinna has up to 12 pairs o f leaflets which have spreading m arginal cilia. The leaflets are o f two different sizes and both occur on the same twig. The smaller leaflets attain a size o f 3 X 0 ,8 mm and the larger 5 x 2,25 mm. The inflorescence axes are pubescent throughout and the pods are up to 4 .7 x 1,4 cm, densely puberulous, and vary from rounded to acute or rostrate apically. Senni 822 is clearly referable to A. Senegal and, as the specimen was collected from a small tree and some o f the pod apices are rostrate, it is hesitantly and provisionally referred to var. rostrata Brenan. Now th at it is established th at A. unispinosa is specifically distinct from A. asak and from A. Senegal, it rem ains to discuss its relationship to A. oliveri Vatke. A. oliveri Vatke in Oest. Bot. Zeit. 30: 274 (1880), was based on Hildebrandt 729c from the Danakil in Ethiopia. Despite repeated attem pts I have not succeeded in tracing a type specimen. However, the description o f A. oliveri is fairly detailed and agrees well with the m aterial o f A. unispinosa except for one im portant discrepancy, namely, the pods o f A. oliveri were described as " legumen adultum 1,2 dm longum , ad 3 cm latum " . The pods o f A. unispinosa are much smaller and only attain a size o f ± 4 ,8 X 1,1 cm.
There is, however, some significant evidence which suggests th at the pod described by V atke did not in fact belong to the specimen o f Hildebrandt 729c. This evidence is in the form o f a sketch in the British M useum of the Berlin specimen o f Hildebrandt 729c, draw n during E. G. Baker's visit to the Berlin H erbarium in 1926. The life-size drawing, which consists o f a vegetative shoot, one inflorescence and three pods, carries the com m ent " pods 2-3-seeded. flat" . The pods are up to 3 ,5 cm long and 1,1 cm wide and these dim ensions are in keeping with the pods o f A. unispinosa. On the strength o f the draw ing o f the Berlin specimen o f Hildebrandt 729c in the British M useum, it seems reasonable to assume that the adult pod described by Vatke did not in fact belong to Hildebrandt 729c and that it inadvertently came from some other source.
Vatke recorded the colloquial nam e o f A. oliveri as " Tikible" . On Bally 7044 (a fairly good m atch o f Fiori 135b, the lectotype o f A. asak var. unispinosa) in the Kew H erbarium , from 15 miles south o f M assawa in Ethiopia, the colloquial nam e is recorded as " Tikkiville" . A lthough spelt som ewhat differently, the two names are phonetically similar and the differences in spelling could perhaps be partially explained by the lapse o f some seventy years between the time when Hildebrandt 729c and Bally 7044 were collected.
As the m aterial at present referred to A. unispinosa matches the draw ing o f the Berlin specimen o f Hilde brandt 729c in the British M useum, agrees with V atke's description o f A. oliveri (with the exception o f the m ature pod), and has a sim ilar colloquial nam e to the one recorded by Vatke, I am reasonably satisfied that A . unispinosa and A . oliveri are one and the same taxon. A. oliveri, being the earlier name, must be adopted for this taxon and A. unispinosa is now reduced to synonymy.