Ceropegia stylesii (Apocynaceae-Asclepiadoideae) - a novel species with rotate flowers from Ngome, South Africa
Author
Heiduk, Annemarie
0000-0002-7857-6646
Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Private Bag X 01, Scottsville, Pietermaritzburg 3209, South Africa & Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, The Netherlands & annemarie. heiduk @ gmx. net; https: // orcid. org / 0000 - 0002 - 7857 - 6646
annemarie.heiduk@gmx.net
text
Phytotaxa
2023
2023-01-17
579
2
117
124
http://dx.doi.org/10.11646/phytotaxa.579.2.5
journal article
226497
10.11646/phytotaxa.579.2.5
96a01d0b-91b8-43a8-8066-9f761601aa40
1179-3163
7543126
Ceropegia stylesii
Heiduk
,
sp. nov.
(
Figs. 1
and
2
)
Type:
—
SOUTH AFRICA
.
KwaZulu-Natal province
,
Ngome
,
975 m
,
04 February 2021
,
D.G.A. Styles & A. Heiduk
5870 (
holotype
:
NU0092554
!)
.
Diagnosis:
—
Ceropegia stylesii
is vegetatively very similar to
C. gerrardii
. The flowers, however, apart from being considerably smaller (diameter ca.
6 mm
vs.>
20 mm
in
C. gerrardii
), are distinct from
C. gerrardii
with ascending corolla lobe tips (vs. radially spreading to reflexed in
C. gerrardii
) which are densely pilose to tomentose (vs. puberulent in
C. gerrardii
). The staminal corona lobes of
C. stylesii
are adpressed to the stamen and the style-head with their tips covering the style-head (vs. erect, exceeding the style-head and protruding as a bundle from the flower centre in
C.
gerrardii
).
Description:
—Plants
perennial, erect herbs.
Rootstock
composed of fleshy, fusiform roots.
Stems
annual, green, rigid, hirsute to hispid, single or two from rootstock,
250–400 mm
tall,
25–35 mm
in diameter, internodes
13–24 mm
, often branched at some internodes starting from second internode.
Leaves
porrect to spreading, shortly petiolate;
petiole
channelled above, hirsute,
1.2–1.8 mm
;
lamina
ovate, 17–30 ×
11–20 mm
, with 3–5 lateral nerves, base cordate, apex acute to obtuse, green, scabrid to hirsute above and below,
margin
entire, undulate, hirsute to hispid.
Inflorescence
axillary, at upper internodes, uniflorous, semi-pendulous;
bracts
narrowly triangular, 3.2–3.6 ×
0.5 mm
, densely hirsute to hispid;
pedicel
hirsute to hispid, green, sometimes reddish-brown speckled, slender, curved, 14–16 ×
0.5 mm
.
Sepals
narrowly lanceolate, acute, radially spreading and protruding from underneath the flower base, hirsute with densely pilose margins, 5.5–6.2 ×
1.5 mm
, slightly reflexed, green with sparse reddish-brown speckles.
Flowers
superficially resembling miniature versions of
C. gerrardii
flowers, with faint sweet scent.
Corolla
rotate, non-tubular, ca. 6.0 mm in length and diameter.
Corolla lobe bases
glabrous, waxy in appearance, creamish-white inside, greenish-white and dark purple speckled outside, basally fused and forming an annulus surrounding the base of the gynostegial column, then free but forming an inflated, apically slightly constricted basket-like structure around the gynostegium, margins fringed with unicellular, clavate, vibratile, ca. 1.0 mm long purple trichomes.
Corolla lobe tips
free, porrect, 3.7–5.0 mm long, radially spreading from basket-like corolla base, replicate, folded back longitudinally forming a raised median ridge, concave below, underside light purple or greenish and purple speckled, scatteredly puberulent, upper surface convex, deeply dark purple to almost black, velvety in appearance, densely pilose to villose, margins with longer stiffer trichomes
0.5 mm
in length.
Gynostegium
shortly stipitate.
Gynostegial corona
of staminal and interstaminal parts, 2.5–3.0 mm in diam., ca.
3.5 mm
in height, forming a nectar cup underneath each guide rail;
interstaminal corona lobes
erect, 0.7 ×
0.6 mm
, each divided into two short lobules, greenish-purple at base, dark purple at tips, with white ca.
0.2 mm
long trichomes;
staminal corona lobes
adpressed to stamen and style-head, covering the latter with tips overlapping (or rarely connivent), 1.5 ×
0.5 mm
, tips slightly asymmetrically bilobed, whitish-purple with dark purple spots, glabrous.
Pollinarium: pollinia
ovoid, ca. 310 × 230 µm, yellow, insertion crest ca. 150 × 50 µm;
caudicles
ca. 50 µm long;
corpusculum
oblong, 215 × 75 µm, brown.
Follicles
paired, narrowly fusiform, ca. 70 × 5.0 mm, glabrous.
Seeds
ovate, brown with lighter brown margin, coma white.