A review of the Euphorbia schinzii-complex (Euphorbiaceae) in southern Africa
Author
Bruyns, Peter V.
Bolus Herbarium, University of Cape Town, 7701 Rondebosch, South Africa
peter.bruyns@uct.ac.za
Author
Klak, Cornelia
Bolus Herbarium, University of Cape Town, 7701 Rondebosch, South Africa
Author
Hanáček, Pavel
Department of Plant Biology, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czechia
text
Phytotaxa
2020
2020-03-19
436
3
201
221
http://dx.doi.org/10.11646/phytotaxa.436.3.1
journal article
10.11646/phytotaxa.436.3.1
1179-3163
13874448
2b.
Euphorbia clivicola
subsp.
calcritica
Bruyns
,
subsp. nov.
This new subspecies differs from
subsp.
clivicola
by the slightly rhizomatous habit, the longer spines, the pale stripe along the middle of the branches and the brownish yellow cyathial glands.
Type:—
SOUTH AFRICA
.
Limpopo
.
20 km
from Zebediela towards Roedtan (2429AD),
1030 m
,
31 October 2011
,
Bruyns 12045
(
holotype
BOL!).
Slightly rhizomatous succulent forming small clusters of branches to
150 mm
in diam.
Branches
40–60(–150) ×
6−10 mm
, subcylindrical, grey-green to brownish green with pale stripe between rows of tubercles;
tubercles
with spine-shields 5–10 ×
1–3 mm
, ±
3 mm
broad above spines and
4–8 mm
long slender and finely acute below spines, bearing 2 spreading initially reddish brown (later grey) spines
5–12 mm
long;
leaf-rudiments
± 0.5 ×
0.7–1.2 mm
, erect, fleeting, ovate, with irregular tiny stipular prickles ±
0.25 mm
long.
Cyathia
and
glands
slightly brownish yellow with reddish bracts.
Distribution & Habitat:
—
Subsp.
calcritica
has only been recorded between Zebediela and Roedtan (
Fig. 2
), though it is likely to occur more widely in this area. At the
type
locality it grows in flat patches with much calcritic rubble on and beneath the surface, among short bushes (mostly <
20 cm
tall) between larger and scattered clumps of trees.
Discussion:
—This new subspecies has been known since a record made by Frank Bayer in 1942 at PRE (photo only), but there are no specimens other than the
type
. It shares with
subsp.
clivicola
the prominent tubercles which are not joined into angles, differing from
subsp.
clivicola
by the slightly rhizomatous habit, the paler markings on the branches and the brownish yellow cyathial glands.