A REVIEW OF THE DIFFERENCES BETWEEN THE SUBSPECIES AND VARIETIES OF TREE SPECIES WHICH OCCUR IN ZIMBABWE by Meg Coates Palgrave
DEFINITIONS ACCORDING to THE KEW PLANT GLOSSARY, (2010) HENK BEENTJE
Species: the Linnaean unit of plant classification denoting a group of populations of similar morphology (external appearance) and constant distinctive character thought to be able to interbreed and produce fully fertile progeny.
Subspecies (subsp.): a subdivision of a species.; each subspecies being geographically or ecologically distinct, isolated from each other and with fewer distinguishing characters than demarcate a species; often used merely in a hierarchical sense of being between a species and a variety.
Variety (var.): a subdivision below the level of subspecies with one or several distinguishing characters, not separated geographically from other individuals of the same taxa.
For photographs and more information about any of the species below, go straight to Flora of Zimbabwe.
Acacia goetzei
subsp. goetzei
Leaflets 5 – 11 pairs per pinna, variable in size usually more than 3mm wide.
subsp. microphylla
Leaflets 8 – 23 pairs per pinna, minute usually less than 3mm wide.
Acacia hebeclada
subsp. chobiensis
Large riverine shrub, the lower branches touching the ground and often half submerged; distance between the nodes up to 4cm; pods more than 2.5cm wide.
subsp. hebeclada
Low spreading shrub to 3m; distance between the nodes up to 1.5cm; pods less that 2.5cm wide.
Acacia robusta
subsp. clavigera
Rachis velvety; pinnae 5-6 pairs; leaflets 13-15 pairs each leaflet about 2-3mm wide; pods sickle-shaped, up to 1.7cm wide.
subsp. robusta
Rachis almost without hairs; pinnae 2 – 4; leaflets about 5mm wide; pods robust, only slightly curved, up to 3cm wide.
Acacia senegal
var. leiorhachis
A slender spindly tree with irregular straggling branches; bark with a conspicuous yellowish papery peel; pod without hairs, longish and narrow (up to 1.9cm wide), apex rounded without a “beak”.
var. rostrata
Growth shrubby, branching low with a dense flattened crown; bark with a pale flaking papery peel; inflorescence axis pubescent; pod, maybe hairy, short and broad (1,2-3,4 cm wide) with a “beak” at the apex.
Acacia sieberiana
var. sieberiana
Leaves and twigs hairless or only sparsely hairy; branches ascending at about 45°, smooth, yellowish or orangish.
var. woodii
Leaves and twigs densely hairy; bark yellowish, flaking off in corky or papery pieces; mature trees often flat topped.
Acacia tortilis
subsp. heteracantha
Pods very twisted, almost hairless and without glands; wide distribution, not confined to riverine or flood plain habitats.
subsp. spirocarpa
Pods, less twisted, with spreading curved hairs and numerous dark red glands (x10 lens) usually occurs in riverine vegetation or on flood plains.
Bridelia cathartica
subsp. cathartica
Leaves seldom longer than 6 cm, usually about 3,5 x 1,5 cm, with up to 14 pairs of closely parallel lateral veins, low-altitude riverine fringe thicket.
subsp. melanthesoides
Leaves up to 12 cm long, with up to 10 pairs of widely spaced lateral veins, mixed open woodland at medium altitudes.
Cassia abbreviata
subsp. abbreviata
Leaves with loose hairs, sometimes curly, pods very velvety.
subsp. beareana
Leaves with very fine straight hairs pressed flat against the surface; pods smooth or only finely velvety.
Carissa bispinosa
subsp. spinosa
Spines stout, numerous up to 4.5cm long; leaves thick broadly ovate to sub-circular; hot dry areas at medium to low altitudes.
subsp. zambesiensis
Spines slender, rather delicate, no longer than 3 cm; leaves, lanceolate, ovate to elliptic; understorey in forest.
Cleistanthus schlechteri
var. pubescens
Ovary and fruit hairy.
var. schlechteri
Ovary and fruit hairless.
Combretum apiculatum
subsp. apiculatum
Mature leaves without hairs except sometimes for tufts in the axial of lateral veins or along the midrib.
subsp. leutweinii
Mature leaves with hairs.
Combretum collinum
subsp. gazense
Leaves medium green to greyish green, with whitish hairs on one or both surfaces; pods rich rusty brown covered with dark, reddish brown scales.
subsp. ondongense
Leaves with undersurface hairless, yellowish green, veins same colour as the leaf and often indistinct; pods pale reddish brown and rather pointed, often shrub-like and occurring mainly on Kalahari sand. This subspecies appears to be the only one which develops galls, which look like small woody fruits without the wings, about 2–3 x 0,5 cm, tapering to both ends and have been recorded as containing small yellow larvae.
subsp. suluense
Leaves drooping, undersurface pale yellowish green, covered with brown scales, midrib and domatia hairy; pods red-brown, densely hairy.
subsp. taborense
Leaves with undersurface pale silvery green, densely covered with white scales; pods hairless, dark red-brown and somewhat pointed.
Combretum psidioides
subsp. dinteri
Leaves with silvery silky hairs, undersurface densely covered with hairs, margin hair-fringed, petiole densely velvety and greyish, tips of petals fringed with hairs.
subsp. glabrum
Leaves hairless below; young leaves glutinous on top; petals not fringed with hairs.
subsp. psidioides
Leaves with sparse hairs on the veins underneath; young leaves not glutinous; petals fringed with hairs leaves densely covered with hairs underneath; young leaves not glutinous; petals fringed with hairs.
Commiphora africana
var. africana
A shrub in mopane; calyx and pedicels hairless.
var. rubriflora
A tree, widespread; calyx and pedicels hairy.
Croton gratissimus
var. gratissimus
Leaves hairless on the upper surface; in a variety of habitats.
var. subgratissimus
Leaves with stellate hairs on the upper surface; sandstone.
Dichrostachys cinerea
subsp. africana
Pinnae 7-19 pairs, 1.5-4.5cm long; leaflets usually less than 6mm long and 2mm wide (2-5 x 0.7-2mm) pods 4-8mm wide.
subsp. nyassana
Pinnae 6-11 pairs, 4-8cm long on the larger leaves; leaflets more than 6mm long and 2mm wide (6-14 2-3mm) pods 4-8mm wide.
Diospyros lycioides
subsp. lycioides
Leaves with secondary veins hardly visible, usually hairless or with a few appressed hairs.
subsp. sericea
Leaves with secondary veins prominently raised, below, usually hairy, sometimes slightly sunken above.
Elephantorrhiza goetzei
subsp. goetzei
Pinnae more than 14 pairs; leaflets 20-48 pairs.
subsp. lata
Pinnae less than 15 pairs; leaflets 9-28 pairs; leaflet width more than 3mm.
Euclea crispa
subsp. crispa
Leaves less than 7 x long as broad.
subsp. lineris
Leaves more than 7 x long a broad.
Euclea natalensis
var. acutifolia
Leaves more than 2.5cm wide.
var. angustifolia
Leaves less than 1.6 cm wide.
Euphorbia confinalis
subsp. confinalis
Single stemmed, 3 – 4 angled.
subsp. rhodesiaca
Stout stem, usually branched; 5 – 6 angled.
Euphorbia cooperi
var. calidicola
Branchlets 3 – 4 winged; wings about 3mm thick. Zambezi Valley.
var. cooperi
Branchlets 4 – 6 winged; wings 5-6m thick.
Ficus natalensis
subsp. graniticola
Sprawling rock-splitter, occurring inland among granite boulders; leaves tending to be truncate or ‘cut off’ at the apex.
subsp. natalensis
Multi-stemmed tree often festooned with aerial roots; distribution more or less coastal, also just into south eastern Zimbabwe.
Ficus sycomorus
subsp. gnaphalocarpa
Figs in ones or twos in the leaf axils, often maturing after the leaves have fallen.
subsp. sycomorus
Figs in heavy, branched masses, shortly stalked, on the trunk and main branches.
Gardenia volkensii
subsp. spatulifolia
Fruit about 6 x 3–5 cm, very shallowly ribbed, with small lenticels; widespread.
subsp. volkensii
Fruit 7–10 cm long, white, with coarse to shallow ribs and conspicuous lenticels occurring in the extreme south east.
Hexalobus monopetalus
var. monopetalus
Leaves oblong to elliptic, lateral veins and reticulate venation visible above.
var. obovatus
Leaves obovate, lateral veins usually prominent on both surfaces.
Hymenocardia acida
var. acida
Leaves often hairless below, fruits hairless.
var. mollis
Leaves with undersurface often velvety, fruits velvety.
Lannea schweinfurthii
var. stuhlmannii
Mature leaves usually more or less hairless.
var. tomentosa
Mature leaves very hairy on both surfaces, particularly the undersurface.
Maerua juncea
subsp. crustata
Flowers with broadly elliptic petals, fruit with very rough skin, resembling a small lemon.
subsp. juncea
Flowers with almost round petals, fruit with a smooth skin.
Newtonia hildebrandtii
var. hildebrandtii
Leaflets more or less hairless or only slightly velvety.
var. pubescens
Leaflets densely velvety.
Pavetta comostyla
var. comostyla
Leaves hairless.
var. inyangensis
Leaves sparsely hairy on both sides.
Pavetta gardeniifolia
var. gardeniifolia
Young branches and leaves hairless, or if hairy only so on the midrib.
var. subtomentosa
All parts usually hairy and hairs on leaves not confined to the midrib.
Protea angolensis
var. angolensis
Suffrutex with numerous simple stems, up to 50 cm high, flowers Jan-Mar.
var. divaricata
Shrub or small tree, flowers May-Jun.
Pseudolachnostylis maprouneifolia
var. dekindtii
Leaves with under surface uniformly pubescent; male inflorescences usually without a stalk. Kalahari sand.
var. glabra
Young shoots and leaves quite hairless; male inflorescences usually with a stalk.
var. maprouneifolia
Leaves with under surface hairy only on the midrib; male inflorescences with a stalk.
Pterocarpus rotundifolius
subsp. martinii
Leaflets 9-13, ovate, apex tapering to a point.
subsp. polyanthus
Leaflets oval to elliptic, 6-9 pairs, lateral veins not distinct on upper surface and with tawny hairs.
subsp. rotundifolius
Leaflets round, 1-3 pairs; lateral veins conspicuous on upper surface and with fine velvety hairs.
Rothmannia fischeri
subsp. fischeri
Leaves elliptic to broadly elliptic or narrowly obovate, apex rounded to tapering occasionally to a point, base tapering; corolla tube more or less funnel shaped, lobes less than 2.5cm long; calyx lobes 1-9mm long; fruit round; widespread in granite kopjes and also in mixed evergreen forest patches; woodland and rocky kopjes.
subsp. moramballas
Leaves narrowly elliptic to elliptic, apex tapering to a point, base tapering; corolla tube more or less bell-shaped, lobes more than 2.5cm long; calyx lobes very reduced, only 1-3mm long; fruit round to pear shaped; prefers wetter conditions; mixed forest and forest and woodland on sand.
Salvadora persica
var. persica
Plants without hairs.
var. pubescens
Plants hairy.
Ximenia caffra
var. caffra
Leaves remain hairy to maturity.
var. natalensis
Leaves without hairs even when young.
Ziziphus mucronata
subsp. mucronata
Leaf under surface with short soft hairs often only on the veins, or hairless.
subsp. rhodesica
Leaves with pale brown rusty hairs particularly on the under surface.
This list updates the list compiled for Tree Life TREE LIFE 109 : MARCH 1989 with the help of Flora of Zimbabwe www.zimbabweflora.co.zw
Meg Coates Palgrave
In drawing up the notes and lists of subspecies and varieties I have used the list prepared by Mr. Bob Drummond and many sources of literature including various volumes of Flora Zambeziaca, Flora of Tropical East Africa, Kew Bulletin, South African and Jeppe, Trees of Southern Africa by Keith Coates Palgrave. My thanks to Bob Drummond, Bryan Adams, Tom Muller, Jonathan Timberlake and Kim Damstra for their help. I really appreciated it. Meg Coates Palgrave