e-Key v3 - Key to Acanthaceae Genera
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Interactive keys to the identification of seed plants of southern Africa using keys based on plant morphology.
Backtrack a
  • Seeds not borne on retinacula
002
b
  • Seeds borne on retinacula
002
Backtrack a
  • Plants with rosulate leaves and scapose inflorescences
  • Scape covered with alternate bracts from base to tip
Elytraria
b
  • Plants with internodes visible between leaves
  • Bracts in inflorescence opposite
002
Backtrack a
  • Plants prostrate, rooting at the nodes
  • Corolla shorter than 12 mm
Nelsonia
b
  • Plants upright herbs or creepers, not rooting at the nodes
  • Corolla longer than 12 mm
Thunbergia
Backtrack a
  • Corolla 1-lipped, with the adaxial suture slit
  • Stamens 4, all monothecous
002
b
  • Corolla 2-lipped, subregular or regular, adaxial suture not slit
  • If 4 stamens present, then at least 2 are 2-thecous
002
Backtrack a
  • Stamens included in corolla tube
  • Filaments epipetalous for most of their length, slender
  • Corolla yellow, orange or red
Crossandra
b
  • Stamens exserted beyond corolla throat
  • Filaments epipetalous for up to half of their length, stout
  • Corolla white, blue or purple or various combinations of these
002
Backtrack a
  • Calyx with 5 lobes
  • Seed surface convoluted and without hygroscopic structures
Sclerochiton
b
  • Calyx with 4 lobes
  • Seed surface with feathery hygroscopic structures
002
Backtrack a
  • Anticous (outer) filaments branched at tip
  • Ovary with 2 glands at tip
  • Style with 2 unequal short branches
Blepharis
b
  • Anticous (outer) filaments not branched at tip
  • Ovary without 2 glands at tip
  • Anticous style branch enlarged and flattened, posticous branch minute
Acanthopsis
Backtrack a
  • Calyx 2-lipped with one lip of 3 lobes and one of 2, lobes fused for most of their length
  • Corolla rotate above, with induplicate aestivation
  • Filaments bifurcate at apex
Neuracanthus
b
  • Calyx not 2-lipped, or if obscurely so, then lobes free for most of their length
  • Corolla not rotate and not with induplicate aestivation
  • Filaments not bifurcate at apex
002
Backtrack a
  • Seeds with hygroscopic uniseriate hairs
  • Corolla aestivation contorted or occasionally imbricate, but then not ascending
  • Fertile stamens 4, or if 2 then pollen with many pseudocolpi ( Chaetacanthus ) or globose with deep reticulations and pores ( Barleria )
002
b
  • Seeds without hygroscopic, uniseriate hairs (although they may have tubercles or hygroscopic glochidiate hairs)
  • Corolla aestivation ascending
  • Fertile stamens 2, or if 4 then pollen colporate with shallow reticulations ( Asystasia , Salpinctium and Glossochilus )
002
Backtrack a
  • Stamens not didynamous
  • Calyx lobes 4, adaxial and abaxial lobes larger than lateral lobes
Barleria
b
  • Stamens didynamous
  • Calyx usually of 5 lobes or if of 4 lobes, then these are equal in size
002
Backtrack a
  • Corolla distinctly 2-lipped and with rugula in upper lip, either with 2 bosses on lower corolla lip or with more than 2 seeds in each locule
002
b
  • Corolla regular or subregular or if 2-lipped then without a rugula in upper lip, without yellow bosses on lower corolla lip and with 1 or 2 seeds in each locule
002
Backtrack a
  • Seeds 2 in each locule
  • Outer lobe of lower lip of corolla outermost in bud, lower lip without yellow bosses
Lepidagathis
b
  • Seeds 5 or more in each locule
  • Corolla contorted in bud and with 2 bosses on lower lip
Hygrophila
Backtrack a
  • Corolla regular
  • Fruits with inelastic placental bases
002
b
  • Corolla distinctly 2-lipped, or if corolla subregular then fruits with elastic placental bases
002
Backtrack a
  • Corolla contorted in bud
  • Disc cupular
  • Inflorescence a highly congested dichasial cyme surrounded by bracts
Crabbea
b
  • Corolla quincuncial in bud
  • Disc annular
  • Inflorescence not as above
002
Backtrack a
  • Anthers spurred
  • Upper lobe of stigma absent
  • Seeds 1 or 2 in each locule
  • Pollen banded
Ruelliopsis
b
  • Anthers muticous
  • Upper lobe of stigma present, although smaller than lower
  • Seeds 3 or more in each locule
  • Pollen with large reticulations
Ruellia
Backtrack a
  • Fruit with elastic placental bases
  • Corolla obscurely 2-lipped
002
b
  • Fruit with inelastic placental bases
  • Corolla clearly 2-lipped
002
Backtrack a
  • Anticous calyx lobe much bigger than other 4 and bigger than bracts
  • Corolla shorter than 15 mm, white, throat yellowish
Phaulopsis
b
  • All calyx lobes equal in size, usually enclosed by a pair of showy bracts
  • Corolla usually longer than 15 mm and showy
Petalidium
Backtrack a
  • Fertile stamens 2
Chaetacanthus
b
  • Fertile stamens 4
002
Backtrack a
  • Capsule with 1 seed in each locule
Duosperma
b
  • Capsule with 2 or more seeds in each locule
002
Backtrack a
  • Capsule with 2 seeds in each locule
Dyschoriste
b
  • Capsule with 3 or more seeds in each locule
Ruellia
Backtrack a
  • Corolla with a distinct rugula in upper lip
002
b
  • Corolla without or with indistinct rugula in upper lip
002
Backtrack a
  • Pollen spheroidal, with a pusticulate ring of exine around the equator
  • Anthers in species with cream flowers attached at right angles to filaments
Isoglossa
b
  • Pollen prolate
  • Anthers attached parallel to filaments
002
Backtrack a
  • Corolla orange, red or yellowy brown, lower lip longer than 25 mm and narrower than 10 mm
002
b
  • Corolla white, cream, lilac, pink, purple or blue, lower lip shorter than 25 mm or if longer, then broader than 10 mm
002
Backtrack a
  • Capsules with elastic placental bases
Metarungia
b
  • Capsules with inelastic placental bases
Anisotes
Backtrack a
  • Corolla tube longer than lips
002
b
  • Corolla tube shorter than lips
002
Backtrack a
  • Style with branches longer than broad
  • Inflorescences terminal as well as axillary
Rhinacanthus
b
  • Style with very short (broader than long) branches
  • Inflorescences axillary
Siphonoglossa
Backtrack a
  • Seeds single in each locule, smooth and shiny
Monechma
b
  • Seeds paired in each locule, rough and often tuberculate (sometimes a single, smooth, shiny seed is borne in an indehiscent capsule)
002
Backtrack a
  • Calyx lobes shorter than tube
  • Staminal channels present in upper lip of corolla and at least half as long as lip
Duvernoia
b
  • Calyx lobes longer than tube
  • Staminal channels absent or less than half as long as upper lip
002
Backtrack a
  • Inflorescence pedunculate and diffuse
  • Anticous corolla lip deeply divided, palate of 2 smooth tumuli (small mounds)
Justicia
b
  • Inflorescence sessile, or if pedunculate then strobilate
  • Palate rugose
002
Backtrack a
  • Lower anther thecae muticous or shortly tailed
  • Lips of corolla nearly equally long
  • Upper lip deeply hooded
Adhatoda
b
  • Lower anther thecae with short or long tails
  • Upper lip of corolla shorter than lower
  • Upper lip shallowly hooded
Justicia
Backtrack a
  • Corolla not resupinate
  • Seeds usually more than 3 mm in diameter
  • Anther thecae ± parallel
  • Inflorescences terminal thyrses or monochasia or single axillary flowers
002
b
  • Corolla resupinate
  • Seeds less than 3 mm in diameter
  • Stamens only 2 and staminodes 0
  • Anther thecae superposed (except where monothecous)
  • Inflorescences axillary, variously reduced 'umbels' of condensed monochasia
002
Backtrack a
  • Stamens 4
002
b
  • Stamens 2
002
Backtrack a
  • Flowers single in axils
Glossochilus
b
  • Flowers in (usually terminal) monochasia or lax terminal thyrses
002
Backtrack a
  • Corolla 2-lipped
  • Pollen with processes associated with pores
Salpinctium
b
  • Corolla campanulate above, ± 2-lipped
  • Pollen without processes associated with pores
Asystasia
Backtrack a
  • Anthers monothecous in chasmogamous flowers
002
b
  • Anthers 2-thecous in chasmogamous flowers
002
Backtrack a
  • Corolla tube considerably longer than upper lip
Ruspolia
b
  • Corolla tube shorter than or ± as long as upper lip
Ruttya (see also
X Ruttyruspolia )
Backtrack a
  • Corolla with lips much longer than tube, throat narrow
  • Disc shallowly cupular
Chorisochora
b
  • Corolla with lips ± as long as or shorter than tube, throat wide
002
Backtrack a
  • Inflorescence with small bracts
  • Calyx easily visible
002
b
  • Inflorescence with large bracts obscuring calyx
002
Backtrack a
  • Corolla subregular, campanulate
  • No cleistogamous flowers present
Mackaya
b
  • Corolla 2-lipped, tubular below
  • Often with cleistogamous flowers
Pseuderanthemum
Backtrack a
  • Corolla thin-textured, lobes ± as long as or longer than tube, bright or pale blue
  • Staminodes 0
  • Pollen prolate, without pseudocolpi, yellow when fresh
Megalochlamys
b
  • Corolla thick-textured, lobes much shorter than tube, green, lilac or white
  • Staminodes 2
  • Pollen almost spheroidal, with pseudocolpi, white or pink when fresh
Ecbolium
Backtrack a
  • Anthers monothecous
Hypoestes
b
  • Anthers 2-thecous
002
Backtrack a
  • Capsules with inelastic placental bases
Peristrophe
b
  • Capsules with elastic placental bases
Dicliptera

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