A study of the genera Justicia L. and Siphonoglossa oerst. (Acanthaceae) in southern Africa
Loading...
Date
1987
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
A comprehensive revision of the genus Justicia L and, the closely
related genera Siphonoglossa Oersted and Aulojusticia Lindau in
southern Africa was undertaken as part of the Flora of Southern
Africa project. Taxonomic characters re-examined include
traditional morphological features and novel characters such as
SEM studies of pollen~ seed and indumentum morphology, as well as
chromatographic work on floral , pigments.
Traditional morphological features examined included habit, the
size and shape of leaves, the corolla, anthers and capsules.
Inflorescence features were thoroughly re-examined. Pollen
morphology was found to be diverse with three types of grain
present in the genus. The number of colpi was either two or three
and there were major differences in the appearance of the sexine.
Pollen and inflorescence type were found to correlate. On the
basis of this a natural infrageneric classification was
proposed.
The seeds showed a number of testa patterns: smooth, papillate,
reticulate or with long scales. These types in many cases also
correlated with the proposed infra-generic classification. The
indumentum of leaves, stems and bracts was examined for each
taxon, and in many cases proved valuable for identification of the
taxon. The floral pigments were analysed using by 2D paper
chromatography but, except in one species, did not prove useful
in species or sectional delimitation.
As a result of these studies, Justicia in southern Africa was
divided into eight sections containing 22 species with six
subspecies. One species and two subspecies were new and there is
one new record for the region. These new taxa and a number of
nomenclatural changes were published by Immelman (1986).
The genus Aulojusticia was reassessed and is here regarded as a
synonym of Siphonoglossa. Siphonoglossa, therefore, is considered'
here to include three species and one subspecies in the southern
African region.
The species and subspecific taxa recognised in this revision are:
Justicia
1. J. glabra Koenig ex Roxb. - N. Botswana, N. Transvaal and
Zululand; also in tropical Africa.
2. J. campylostemon (Nees) T. Anders. - from N.E. Transvaal to E.
Cape. 3. J. bolussi, C.B. Cl. restricted to the E. Cape and the
Transkei.
4. J. betonica L. - from N. Namibia and N.E. Botswana, through
the Transvaal to the E. Cape; also in tropical Africa and
India.
5. J. montis-salinarum A. Meeuse - restricted to the Soutpansberg
(N. Transvaal).
6. J. flava (Vahl) Vahl - from E. Botswana through the Transvaal
and Natal to the Transkei, also widespread in Africa.
7. J. kirkiana T. Anders. - a common species in Africa, occurring
in the region covered only from two localities in N. Botswana.
8. J. petiolaris (Nees) T. Anders. -
(a) subsp. petiolaris from E. Transvaal to the Transkei
(b) subsp. bowiei (C.B. Cl.) Immelman stat. nov. restricted
to the E. Cape
(c) subsp. incerta (C.B. Cl.) Immelman stat. nov. from the
Transvaal and Zululand.
9. J. protracta (Nees) T. Anders. -
(a) subsp. protracta from the Transvaal to the S. Cape
(b) subsp. rhodesiana (S. Moore) Immelman stat. nov. from
Namibia, W. Botswana and the N. and E. Transvaal.
10. J. parvibracteata Immelman sp. nov. - from the N. Cape, with
one record from the N. Transvaal.
11. J. dinteri S. Moore
Transvaal.
N. Namibia, N.E. Botswana and W_o
12. J. odora (Forssk.) Vahl - N. Namibia, N. and E. Botswana, the
Transvaal and Natal, also in tropical Africa.
13. J. capensis Thunb. N. Natal and also, disjunctly, the
Transkei and E. and S. Cape.
14. J. cuneata Vahl -
(a) subsp. cuneata which is restricted to the E. Cape
(b) subsp. latifolia (Nees) Immelman from Namaqualand, W.
Karoo and E. Cape (c) subsp. hoerleinlana (P.G. Mey.) Immelman stat. nov.
from S. Namibia
15. J. Orchioides L. f. -
(a) subsp. orchioides restricted to the E. Cape
(b) subsp. glabrata Immelman subsp. nov. from the S. and
E. Cape, E. Karoo, O.F.S., and S.W. Transvaal.
16. J.thymlfoila (Nees) C.B. C1. - restricted to the N. Cape.
17. J. guerkeana Schinz - mainly in S. Namibia.
18. J. platysepala (S. Moore) P.G. Mey. - mainly in N. Namibia.
19. J. minima A. Meeuse - endemic to the Waterberg (Transvaal).
20. J. a nagalloides (Nees) T. Anders. - Transvaal to Natal.
21. J. crassiradix Burkill & Clarke (new record for southern
Africa) - one record from the E. Caprivi.
22. J. anselliana (Nees) T. Anders. - N. Namibia, N. and E.
Botswana and the Transvaal.
Siphonoglossa
1. S. leptantha (Nees) Immelman -
(a) subsp. leptantha - from Natal to the E. Cape
(b) subsp. late-ovata - (C.B.Cl.) Immelman comb. nov. ined.
from the E. to the S. Cape.
2. S. nkandlaensis Immelman sp.nov. ined. - Central Natal.
3. S. linifolia (Lindau) C.B. Cl. (= Aulojusticia linifolia
Lindau) - endemic to the Barberton area (Transvaal).
A formal taxonomic revision including keys to genera, sections
and species has been included.
Description
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1987.
Keywords
Acanthaceae., Justicia., Siphonoglossa., Theses--Botany.