Southern A frica has one of the highest known concentration of
threatened plant species in the world (Cowling & Hilton-Taylor
1(94). This is a consequence of the very large number of species
all the subcontinent (>20 000), es pecially endemics, and possibly
a greater diversity and severity of threats to their persistence.
Many threatened plant species are not represented in present
nature rese rves. The four provinces making up the fanner Transvaal
Province are host to over 400 threatened plant species
(W.M. Boyd unpublished; Hillon-Tay lor 1996). Many were the
focus of cons iderable research effort under the 'Transvaal
Threatened Plant Programme' (TT??; Hall et al. 1984; Fourie
1986). With the divi sion of the Transvaal into four separate provinces
in 1994, the conservation authorities within each of the
new provinces have been restructured. Many of the activities of
the ITPP, such as monitoring of endangered species, are curren
tly ( 1994-97) not being undertaken. For many threatened species.
conse rvation plans have been developed which emphasize
the need for more detailed autecological studies on Vulnerable
and Endangered species. One of these Vulnerable species is
Hmvorthia koelmaniorum Oberm. & Hardy (Boyd 1994; Hilton-
Taylor 1996; family- Asphodelaceae), which is protecled
under Transvaal Nature Conservation Ordinance No. 12 of 1983.
Thirty-five percent (40 of approx imately 115 taxa) of Hall'ol'lhia
in so uthern African are threatened (Hi lton-Taylor & Smith
1994). In the recent Red Data List update, no Hall'orlhia, indeed
no Asphode1aceae, were placed in the 'Out of Danger' category
(H ilton-Taylor 1996), implying that there have been no effective
conservati on measures to safeguard these taxa and the threats are
sti ll operating.
H. koelrnaniorllnl is a small rosulate leaf succulent species
(full description in Obermeyer 1967) resl ricted to 7 populations
occurring on the slopes of quartzite ridges, none of which are situated
within a nature reserve. Taxonomically, H. koelmaniorum
is close to H. !imi/olia Mar loth var. !imi/olia, but geographically
it is closest to H l1u.·ll11trll yi c.L. Scott (Scott 1985); all three
making up the section Limifo liae. A distinctive feature is that
they are all sto loniferous. These are also the only three known
Hmvorthia species in the 'Transvaal' . The widespread H IimUolio
has been extensively collected fo r tradi tional medicine
(Hutchings 1989), resulting in serious depletion of wild populations
and consequently greater collecting pressure 0 11 related species.
Threats to most Hall'orlhia spp. are exacerbated by small
population size (Hilton-Taylor 1996). The distribution pattern of
Haworthia Duval, which is near endemic to South Africa (a lso
reported from Mozambique and Nami bia), is largely restricted to
the summer dry, semi-arid coastal regions below th e inland
escarpment, with outl iers in the arid valleys of KwaZulu-Natal,
Swaziland and Mpumalanga (Hillon-Taylor & Smith 1994).
The conservation report for H koeill10llioruI7I determined that
there were 1800- 2000 plants (Boyd 1994) . Perceived threats to
the conservation of H koe/1I10niol'lIl11 incl uded the removal of
plants by succulent collectors and for traditional medicine or
(Boyd 1994). Furthermore, the Japanese s licculent plant co ll ec~
tors in particular have become very keen on the diminutive
Haworthia spp. in recent years.
The aim was to study the population structure, habitat profile
and regeneration of H koeinumiontJ1l , within the context of its
landscape to aid it's conservat ion (s ellsu Pi ckett el at. 199:!). The
approach to the study follows that of Lamont et 01. (1993), Witkowski
and Lamont ( 1997) and Witkowski el af. ( 1997). jvlany
studies of threatened species describe the habitat of the species
from sampling only where it is presently found , without cons idering
similar habitat where it is not found. Thus, an additional
aim was to compare the habitat of H. koe/llumiorllfll where it is
found with similar complimentary sites where it does not occur.
Despite the large number of threatened taxa in th e Transvaal,
very few detailed studies have been published (Raal 1988;
Scholes 1988)) and none have yet been published on olher
HalVorthia spp. in southern Africa.