Flora of Southern Africa - Trees, Grasses, and Wild Flowers

Vocabulary flashcards covering Lowveld catena ecology, tree species, grass ecological classifications, and wild flowers based on FGASA EcoTraining Southern Africa notes.

Catena

A connected series or chain of soil types and associated vegetation along a slope, showing distinct ecological zones from the crest down to the drainage line.

Crest (Catena)

The top and upper parts of a slope characterized by coarse, well-drained, relatively infertile sandy soil, favoring trees like Marula (Sclerocarya birrea) and Red Bushwillow.

Seepline

A waterlogged band located on a contour midway down a slope where rainwater infiltrating sandy topsoil meets denser clay soil and resurfaces; characteristically inhabited by Silver cluster-leaf trees.

Sodic site

A bottomland area adjacent to drainage lines with extremely hard, sodium-rich sub-soils that restrict root growth, creating an erodible, water-impermeable surface dominated by Magic guarri bushes.

Drainage line

A feature formed along linear weaknesses in underlying granite, filled with coarse sand and sometimes crossed by dolerite dykes that trap water underground on their upstream side.

Knob Thorn (Senegalia nigrescens)

A tall tree ($18\,m$) of footslope clay soils with raised woody thorn-tipped knobs on stems, paired hooked thorns, bipinnate butterfly-like leaflets, elongated white flower spikes, and non-splitting flat pods.

Fever Tree (Vachellia xanthophloea)

A $10\text{--}30\,m$ tree of floodplains and swampy river areas with powdery yellow-green bark, long paired white thorns ($< 85\,mm$), feathery bipinnate leaves, and yellow pom-pom flowers.

Umbrella Thorn (Vachellia tortilis)

An $18\,m$ icon of the bushveld with a flattened umbrella-shaped canopy, tiny feathery leaflets, contorted helical pods, and a mixture of small hooked thorns and large straight thorns in opposite pairs.

River Thorn (Vachellia robusta clavigera)

A $25\,m$ robust tree of fertile river clay soils with dark fissured bark showing reddish cracks, excessively long thorns ($10\text{--}15\,cm$) paired with small $5\,mm$ thorns, and creamy flower clusters.

Green Thorn (Balanites maughamii)

A $10\text{--}20\,m$ tree with a deeply fluted lower trunk, smooth grey bark, Y-shaped green spines ($< 7\,cm$), bifoliate leaves, and date-like fruits with seeds containing highly flammable oil.

Baobab (Adansonia digitata)

An iconic long-lived tree ($25\,m$) with a hugely swollen fibrous trunk ($2\text{--}8\,m$ diameter) containing $40\%$ water, digitate palmately compound leaves, and large velvety mango-shaped fruits rich in Vitamin C.

Tree Wisteria (Bolusanthus speciosus)

A $4\text{--}10\,m$ tree of heavy alkaline soils with termite- and fire-resistant wood, asymmetric imparipinnate leaflets, and hanging $30\,cm$ clusters of purple grape-like flowers.

Shepherd's Tree (Boscia albitrunca)

A $7\,m$ evergreen tree of arid sandy soils with a smooth white trunk, flat umbrella canopy, whorled simple leathery leaves ($14\%$ protein), and leafless branch tips giving a spiky appearance.

Mopane (Colophospermum mopane)

A shrub or tree ($< 20\,m$) dominating clay soils, featuring butterfly-shaped bifoliolate leaves that fold in heat and smell of turpentine, hard termite-resistant wood, and resinous kidney-shaped pods.

Red Bushwillow (Combretum apiculatum)

A $10\,m$ tree of upper catena sandy slopes with secondary branches at $90^\circ$, twisted leaves with hooked tips, dense wood ($1230\,kg/m^3$), and 4-winged pods glutinous when young.

Russet Bushwillow (Combretum hereroense)

A multi-stemmed shrub or tree appearing rusty brown from a distance due to small 4-winged pods, with oval leaves covered in russet-coloured hairs on raised veins underneath.

Leadwood (Combretum imherbe)

A long-lived ($> 1000$ years) sweetveld indicator tree ($7\text{--}15\,m$) with extremely heavy wood ($1200\,kg/m^3$), grey bark resembling crocodile skin, and wavy leaves with tiny grey scales.

Zebrawood (Dalbergia melanoxylon)

A $5\text{--}10\,m$ multi-stemmed untidy shrub or tree with purple-black heartwood, pale papery flaking bark, compound leaves, and branchlets modified into ladder-like alternating spines.

Sickle Bush (Dichrostachys cinerea)

A $5\text{--}7\,m$ encroaching shrub or tree with bipinnate feathery leaves, single strong branch spines, bi-colored pink and yellow lantern-like flower clusters, and contorted pod bunches.

Jackal-berry (Diospyros mespiliformis)

A massive tree ($< 25\,m$) along rivers and termitaria with dark bark washed white on top, alternate elliptic tannin-rich leaves, and green sticky berries known as 'pear of the gods'.

Velvet-leaved Cork Wood (Commiphora mollis)

An $8\,m$ tree of hot dry rocky bushveld with thick discs of flaking silvery bark, watery milky sap, soft silky-haired imparipinnate leaves, and fleshy reddish drupes.

Bushveld Gardenia (Gardenia volkensii)

A $3\text{--}8\,m$ tree with smooth pale grey bark, 3-whorled glossy spoon-shaped leaves, large night-opening white star flowers, and longitudinally ribbed fruits with whitish lenticels.

Satin Bark Saucer-Berry (Cordia ovalis)

A shrub or small bushy tree with smooth pale grey to green soap-like bark, sandpaper-rough circular/ovate leaves, and orange-red ovoid drupes cupped in a persistent calyx.

Woolly Caperbush (Capparis tomentosa)

A scrambling shrub, creeper, or small tree with soft velvety hairs on greyish-green simple leaves, paired hooked velvety spines at petiole bases, and globose pinkish to orange berries.

Magic Guarri (Euclea divinorum)

An evergreen shrub abundant on brackish sodic clay soils at catena bases, featuring opposite wavy-margined elliptic leaves, Y-shaped branches used for water divining, and purplish-black single-seeded fruits.

Large-leaved Rock Fig (Ficus abutifolia)

A $10\,m$ gnarled tree growing on boulders with roots that split rocks, featuring white bark, non-toxic milky latex, and heart-shaped leaves ($15 \times 20\,cm$) with prominent venation.

Sycamore Fig (Ficus sycomorus)

A large ($30\,m$) riverine forest tree producing up to four crops of pale pink figs directly on main branches per year, with rough cat's-tongue leaves and soft carveable wood.

Sausage Tree (Kigelia africana)

A $25\,m$ tree with a dense mushroom canopy, deep red trumpet flowers on long hanging stems, and giant woody sausage-like fruits measuring up to $60\,cm$ and weighing $5\text{--}10\,kg$.

Sandpaper Raisin (Grewia flavescens)

A $1\text{--}5\,m$ shrub or tree characterized by 4-angled square branches, serrated sandpaper-rough leaves, yellow star-shaped flowers, and 2-to-4-lobed brown raisin-like fruits.

Apple-leaf (Philenoptera violacea)

A groundwater indicator tree with a meandering trunk, poisonous compound leaves that smell like apple when crushed, and hanging pale violet grape-like flower bunches.

Common Spike-thorn (Gymnosporia buxifolia)

A variable shrub or small tree with deeply fissured bark, rubbery leaves clustered at the base of spines ($< 10\,cm$), and unpleasantly scented small white flower heads.

False Marula (Lannea schweinfurthii)

A $10\,m$ dioecious tree resembling marula, growing on termite mounds and rocky outcrops, with grey bark peeling in stripes, unstalked leaflets, and wine-red grape-like fruits.

Marula (Sclerocarya birrea)

A $7\text{--}18\,m$ dioecious tree of well-drained sandy catena crests, with bark peeling in circular discs with white dots, long-stalked imparipinnate leaflets, and plum-sized yellow fruits rich in Vitamin C.

African Wattle (Peltophorum africanum)

A $10\text{--}15\,m$ non-acacia tree of sandy bushveld with velvety bipinnate leaves, spectacular erect bright yellow flower clusters, flat tear-shaped pods, and frequent spittle-bug infestations.

Weeping Boer-bean (Schotia brachypetala)

A $25\,m$ tree of riverbanks and termitaria with paripinnate leaves with winged rachises, deep red nectar-dripping flowers, and seeds that can be roasted as a coffee substitute.

Black Monkey-orange (Strychnos madagascariensis)

A $6\text{--}18\,m$ shrub or tree with erect bunched stems, 3 prominent veins originating at leaf bases, and large dull yellow fruits with purgative seeds.

Tamboti (Spirostachys africana)

An $18\,m$ tree of clay drainage lines with grey-black grid-patterned bark, toxic skin-irritating latex, poisonous wood smoke, catkin-like spikes, and jumping 3-lobed seed capsules.

Silver Cluster-leaf (Terminalia sericea)

A $6\text{--}20\,m$ key seepline indicator tree with lance-shaped leaves covered in silvery hairs, 2-winged pinkish-red to brown pods, and bark used for making ropes.

Purple-pod Cluster-leaf (Terminalia prunioides)

A fountain-like shrub or tree of hot drier bushveld with dark green leaves clustered at branch tips, unpleasantly scented white-cream flower spikes, and large wine-red to purple 2-winged pods.

Sourplum (Ximenia caffra)

A sparse shrub or tree ($< 6\,m$) acting as a hemi-root parasite, with spinescent branchlets, folded leathery leaves, and bright red sour edible drupes with oil-yielding seeds.

Buffalo-thorn (Ziziphus mucronata)

A shrub or tree with zigzag branches, paired stipular spines (one straight, one hooked), shiny ovate leaves, and red berry drupes; culturally valued as the 'Tree of life'.

Naboom (Euphorbia ingens)

A succulent evergreen tree ($10\,m$) shaped like a candelabrum with 4- or 5-angled photosynthetic branch segments, paired $2\,mm$ spines, and extremely toxic milky latex.

Sweetveld

A low-altitude grassland type ($250\text{--}500\,mm$ annual rainfall) with frost-free climates, low soil leaching (alkaline soil), and highly palatable grass species that retain grazing value year-round.

Sourveld

A high-altitude grassland type ($> 500\,mm$ annual rainfall) with winter frosts, acidic leached soil, and grasses that become woody and unpalatable past early growth stages.

Increaser 1

A grass species classification that increases in abundance when veld is under-utilized or under-grazed.

Increaser 2

A grass species classification that increases in abundance when veld is over-grazed or over-utilized.

Decreaser

A palatable grass species dominant in good-condition veld that decreases in abundance under over-grazing or under-grazing.

Glume

A boat-shaped bract found at the base of a grass spikelet.

Carrot Seed (Tragus berteronianus)

A short annual Increaser 2 pioneer grass with barbed spikelets that stick to clothes and fur; indicates over-utilized, hard, or drought-stricken soils.

Tassel Three-Awn (Aristida congesta)

A poor-grazing pioneer Increaser 2C grass of sour/mixed veld whose spikelet shaft splits into three corkscrew-twisted awns; helps stabilize disturbed soil.

Natal Redtop (Melinis repens)

A pioneer to sub-climax Increaser 2 grass with fluffy red inflorescences that turn white at maturity, common on disturbed well-drained soils along roads.

Cats Tail (Perotis patens)

A sparsely tufted pioneer Increaser 2a grass ($< 1\,m$) of poor sandy soils, with long slender spikes of densely packed spikelets bearing long hair-like awns.

Blue Seed Grass (Tricholaena monachne)

A sub-climax Increaser 2 sweetveld grass of sandy soils with delicate panicles whose culm nests are used by Blue Waxbills for nest construction.

Couch Grass (Cynodon dactylon)

A perennial creeping pioneer Increaser 2b grass ($< 30\,cm$) with stolons and slender rhizomes, forming dense carpets in nitrogen-rich or disturbed soils.

Herringbone Grass (Pogonarthria squarrosa)

An erect sub-climax Increaser 2C grass of sandy seepline soils with red-brown racemes shaped like the cleaned bones of a fish.

Sawtooth Love Grass (Eragrostis superba)

An Increaser 2a pioneer/sub-climax grass featuring large, flat, heart-shaped spikelets resembling wheat kernels; palatable when young.

Guinea Grass (Panicum maximum)

A high-value climax Decreaser grass growing up to $2.5\,m$ in shady, damp, nutrient-rich soils under acacia trees and along rivers.

Turpentine Grass (Cymbopogon excavatus)

An Increaser 1 climax grass containing aromatic citronella oils that smell like turpentine when crushed, rendering it unpalatable to grazers.

Red Grass (Themeda triandra)

A premier climax Decreaser grass turning red at the end of growth periods; serves as an indicator of good veld condition and is highly palatable.

Yellow Thatch Grass (Hyperthelia dissoluta)

A tall ($< 3\,m$) tufted sourveld climax Increaser 1 grass with stiff narrow panicles, grazed early before becoming woody; utilized for thatching.

Finger Grass (Digitaria eriantha)

A fast-growing perennial climax Decreaser grass ($1.4\,m$) with a digitate panicle of 3 to 15 finger-like racemes, providing high grazing value.

Southern Common Reed (Phragmites australis)

A tall ($< 4\,m$) wetland climax Decreaser reed forming dense stands near water, purifying waterways and providing dry-season grazing for large herbivores.

Spear Grass (Heteropogon contortus)

A sub-climax Increaser 2/3 sourveld grass with dark, velvety, twisted awns that easily penetrate skin, grazed mainly early in the season.

Leopard Orchid (Ansellia africana)

An epiphytic orchid found on riverine trees in Kruger National Park with sweetly scented flowers that attract hawk moths at night.

Mistletoe (Tapinanthus spp.)

An obligate hemiparasitic plant genus of order Santalales endemic to Africa, characterized by tubular flowers frequently visited by sunbirds.

Impala Lily (Adenium multiflorum)

A succulent plant considered a subspecies of Adenium obesum, producing a toxic milky latex traditionally used as arrow poison.

Black Stick Lily (Xerophyta retinervis)

A fire-resistant perennial plant with black fibrous stems that flowers rapidly after rain or fire, commonly found on rocky outcrops.

Wild Basil (Ocimum americanum)

An annual herb with white or lavender flowers, native to Africa, Asia, and parts of South America despite its species name.

Mother-In-Law's Tongue (Sansevieria trifasciata)

An evergreen perennial plant native to tropical West Africa with creeping rhizomes and upright, banded leaves.

Blue Commelina (Commelina erecta)

A perennial herb featuring bright blue flowers that bloom for only a single day, used medicinally for wound treatment.

Red Star Zinnia (Zinnia peruviana)

An annual herb up to $70\,cm$ native to South America; acts as an invasive weed in Southern Africa with low ecological impact.

Wild Dagga (Leonotis leonurus)

An herbaceous perennial ($1\text{--}2\,m$) attracting sunbirds and butterflies, known for its calming, psychedelic, anti-inflammatory, and cardio-protective effects.

Ruby Gnidia (Gnidia rubescens)

A multibranched shrub ($< 1.5\,m$) with multi-coloured flowers and a strong night fragrance adapted for moth pollination; toxic to cattle.

Flannel Weed (Sida cordifolia)

An erect perennial ($50\text{--}200\,cm$) covered in white flannel-like hairs, native to India and naturalized in Africa, used medicinally for respiratory conditions.

Wild Hibiscus (Hibiscus engleri)

A shrub or small tree with rough lobed leaves and short-lived one-day yellow/pink flowers with dark centers, producing cotton-like silky seeds.

One Day Lily (Pancratium tenuifolium)

A bulbous herbaceous perennial pollinated by hawkmoths, representing the only Pancratium species native to southern Africa.