Kalanchoe benbothae (K. subg. Fernandesiae; Crassulaceae subfam. Kalanchooideae), a new southern African species endemic to KwaZulu-Natal in the Maputaland-Pondoland Region of Endemism
Author
Smith, Gideon F.
0000-0002-5417-9208
Department of Botany, Nelson Mandela University, P. O. Box 77000, Gqeberha [Port Elizabeth], 6031 South Africa. smithgideon 1 @ gmail. com; https: // orcid. org / 0000 - 0002 - 5417 - 9208
smithgideon1@gmail.com
Author
Crouch, Neil R.
Biodiversity Research and Monitoring Directorate, South African National Biodiversity Institute, P. O. Box 52099, Berea Road, Durban, 4007 South Africa. & School of Chemistry & Physics, University of KwaZulu-Natal, Durban, 4041 South Africa.
text
Phytotaxa
2021
2021-09-28
521
2
105
112
http://dx.doi.org/10.11646/phytotaxa.521.2.4
journal article
4191
10.11646/phytotaxa.521.2.4
48cef009-33e4-4cf4-98c3-35f17ad3533f
1179-3163
5533581
Kalanchoe benbothae
Gideon F.Sm. & N.R.Crouch
,
sp. nov.
(
Fig. 1A–E
)
Type
:—
SOUTH AFRICA
.
KwaZulu-Natal province
—2731 (Louwsburg):
Vaalbank
, (–
CA
), rocky grassland to northeast of town, sterile material collected in
February 2017
, flowered in cultivation in Durban,
2 June 2021
,
B
.
S
.
[
Ben
]
Botha
1
(
holotype
PRU
)
.
Diagnosis
:—Plants of
Kalanchoe benbothae
(
Fig. 1B
) are medium-sized to large, glabrous, densely waxy when young, bi- to triennial to perennial succulents that can be separated from
K. luciae
(
Fig. 2
), its closest relative, as follows:
Kalanchoe benbothae
is less robust in all vegetative respects than
K. luciae
, with especially the leaves of the former (90–140 ×
60–100 mm
) not attaining the dimensions of the latter (40–160(–190) × 20–90(–110) mm) (
Fig. 1B
). The flowers of
K. benbothae
are lightly to moderately covered in a waxy bloom (
Fig. 1A
), while those of
K. luciae
have a substantial waxy bloom (
Fig. 2A–B
). The corolla lobes of
K. benbothae
are reddish pink and triangular, while those of
K. luciae
are white to pale yellowish green and oblong (
Fig. 1A, C–D
). The anthers of
K. benbothae
are reddish brown in bud, while those of
K. luciae
are yellow, and the pistil of the former is narrowly elliptic, whereas that of the latter species is prolate.
Kalanchoe benbothae
has transversely oblong nectar scales, while those of
K. luciae
are ± square (
Fig. 1E
).
Description
:—Multiannual to perennial, few- to many-leaved, unbranched at first, pre- and/or post-flowering slowly sprouting from woody base, glabrous, waxy, medium-sized to robust succulent, 0.25–1.00 m tall when in flower.
Stems
light green to reddish-infused, unbranched, arising from sturdy base, erect to leaning, often with few indistinct, lengthwise running ridges.
Leaves
opposite-decussate, light green, infused with red to purplish red along leaf margins only, succulent, erect to slightly erectly spreading, coriaceous and papery-flimsy on drying;
petiole
absent, amplexicaul;
blade
90–140 ×
60–100 mm
, obovate to broadly elliptic, somewhat gracefully and slightly folded upwards lengthwise, sometimes very slightly wavy, flat to slightly curved up along margins;
base
cuneate to narrowly triangular, sometimes very slightly auriculate;
apex
rounded-obtuse;
margins
smooth, slightly saucer-like curved upwards.
Inflorescence
erect to slightly leaning, apically dense, many-flowered, club-shaped to short-branched thyrse consisting of several dichasia terminating in monochasia, flowering portion 100–400(–700) mm long, branches opposite, rarely only one at node, erect to slanted away from main flowering stem at angle of 30°, subtended by leaf-like bracts, very rarely with leafy branchlets in axils, axis light green;
pedicels
3–10 mm
long, slender.
Flowers
erectly spreading to slanted horizontally to pendulous at anthesis;
calyx
light green to lightly reddish-infused, very densely white-waxy covered;
sepals
4, ± 3–4 ×
1.5–2.5 mm
, narrowly triangular-lanceolate, succulent, clasping the corolla tube above, basally fused for 1.0–
1.5 mm
, acute-tipped, contrasting against light yellowish green corolla tube;
corolla
12–14 mm
long, enlarged lower down, tapering to mouth, not twisted apically after anthesis;
tube
11–13 mm
long, light yellowish green, fading reddish brown when spent, narrowly urceolate, indistinctly 4-angled, round when viewed from below, longitudinally indistinctly fluted above;
lobes
(3–)5 ×
3 mm
, pink to reddish with margins often paler, triangular, tapering towards acute apex, margins slightly to distinctly in-folded, erecto-patent, rarely recurved, dark pink to red-tipped in bud.
Stamens
8, inserted in two ranks, one rank just above middle of corolla tube, other well above middle of corolla tube towards mouth, all 8 slightly exserted to
1 mm
, visible at mouth;
filaments
2–4 mm
long, light greenish white, thin, tapering upwards;
anthers
0.5–0.6 mm
long, yellow.
Pistil
consisting of 4 carpels, narrowly elliptic;
carpels
6–7 mm
long, dull mid-green;
styles
1.5–2.0 mm long, dull mid-green;
stigmas
very slightly capitate, whitish green, positioned at mouth;
scales
±
1 mm
high, ±
2 mm
broad, transversely oblong, flat to slightly tooth-like rounded and finely cockscomb-like pointed apically, uniformly light yellow.
Chromosome number
: unknown.
Distribution and habitat
:—The earliest known material of
K. benbothae
was collected at Mooiklip near Louwsburg in 1936 by the indefatigable South African botanist Inez Clare Verdoorn (1896–1989), who was employed at the National Herbarium in Pretoria (Herb. PRE) from 1919 until 1951, and later (1967) was awarded an honorary Ph.D. degree by the University of Natal. The species was recently recollected.
This new species is known with certainty so far only from the
type
locality at Vaalbank in
KwaZulu-Natal
and also from Mooiklip some
20 km
distant. However, based on sterile material it is considered to possibly occur also some
110 km
to the north of Vaalbank at Iswepe, situated in KaNgwane Montane Grassland (Gm16) (David Styles pers. comm.;
Mucina
et al
. 2006
). The entire known natural geographical distribution range (
Fig. 3
) of the species falls within the Maputaland-Pondoland Region of Endemism (
Van Wyk & Smith 2001: 82–85
).
Kalanchoe benbothae
occurs in very shallow soils overlying dolomitic bedrock, in open grassland at elevations of
ca
.
1250 m
, in Northern
KwaZulu-Natal
Moist Grassland (Gs4) and Northern Zululand Mistbelt Grassland (Gs 1) (
Mucina
et al
. 2006
). It co-occurs with
Aloe suprafoliata
Pole Evans (1916: 603)
and
Aloe
cf.
minima
Baker (1895: 153)
[both
Asphodelaceae
]. At the Vaalbank site some 50 plants have been observed, whilst at the unconfirmed Iswepe site
ca
. 30 plants were noted. The
type
locality is formally unprotected and subjected to grazing by cattle, whilst the original locality (Mooiklip) at which it was discovered, is presently threatened by coal mining activities.
Additional specimen examined
:—
SOUTHAFRICA.
KwaZulu-Natal province
[as “Natal”].—2731 (Louwsburg):
Ngotshe
,
Mooiklip
near
Louwsburg
(–
CA
),
30 July 1936
,
I
.
C
.
Verdoorn
1720
(
PRE
!)
.
Flowering time
:—
Kalanchoe benbothae
flowers mainly in the winter months, May to August in the southern hemisphere, although in cultivation there as early as January.
Eponymy
:—
Kalanchoe benbothae
is named for Mr B.S. (Ben) Botha (born
4 September 1961
, Elliot,
Eastern Cape Province
,
South Africa
–), a nurseryman and succulent afficionado, especially of aloes across their global range. Ben Botha is apparently the first to have gathered material of
K. benbothae
since Inez Verdoorn collected it some 80 years earlier in 1936; he is credited for recognising it as distinct from
K. luciae
. Within the greater Durban region,
KwaZulu-Natal
,
South Africa
, Ben has been highly active in promoting waterwise gardening with succulents (
Fig. 1F
).