A taxonomic revision of Schoenus cuspidatus and allies (Cyperaceae, tribe Schoeneae) - Part 1 *
Author
Elliott, T. L.
Author
Barrett, R. L.
Author
Muasya, A. M.
text
South African Journal of Botany
2019
2019-03-31
121
519
535
http://dx.doi.org/10.1016/j.sajb.2018.11.021
journal article
10.1016/j.sajb.2018.11.021
1727-9321
10496596
10.
Schoenus purpurascens
T.L.Elliott & Muasya
,
sp.nov.
Type:
South Africa
,
Western Cape Province
, 3419 (
Caledon
): Nidderdale Farm, S.E.- facing slope to N.E. of
Babylon's Tower
peak, near top of peak, (–AD),
5 May 2018
,
Elliott
,
Muasya
and
van Mazijk
TE2016_349
(
BOL
!,
holo
.,
MT
!,
NBG
!,
iso
.).
Caespitose, phyllopodic perennial graminoid.
Culms
terete, slender, (193–)339–528(—732) ×
0.4–0.9 mm
.
Leaves
basal, 2–4(—8), (4–) 54–149(—392) ×
0.2–1.4 mm
, mostly straight, usually not proximally channelled, margin usually serrate above sheath.
Sheaths
membranaceous with reddish-purple streaks, usually loosely clasping culm, longitudinally striate.
Ligule
membranaceous, varying lengths, 0.3–1.1(—9.2) mm long.
In
fl
orescence
a pseudolateral panicle, 9–33(— 45) ×
3–12 mm
, proximal rachis length 4–16(—29) mm.
Proximal primary in
fl
orescence bracts
slender, not channelled, apex acute to acuminate, never widened at base, 29–66(—206) mm long, exceeding length of inflorescence up to several times, without notable longitudinal veins. Proximal and subproximal primary inflorescence bracts never with membranaceous extensions at base.
Spikes
2–11, (4.0–) 7.4–19.0 mm long, usually dispersed along rachis.
Spikelets
ovate, 2.6–4.1 × 1.0–
1.7 mm
, pedicellate, 2–10 spikelets per spike, reddish-brown sometimes with narrow hyaline margins.
Proximal spikelet prophyll
1 per spikelet, with a raised vein extending to mucro,
0.4–1.1 mm
long, prophyll mucro 0.8–2.5(—3.6) mm long.
Rachilla
0.8–2.8 mm
long.
Glumes
4–7 per spikelet, proximal glume
0.4–1.8 mm
long, subproximal glume
0.6–2.2 mm
long, upper glumes longer than basal ones, apex acute to acuminate. Glume mucros relatively short, proximal mucro
0.1–0.8 mm
long, subproximal mucro
0.1–0.3 mm
long.
Stamens
(1–)3(—5) per floret, anthers
1.3–3.7 mm
long.
Stigmas
3-branched, vestigial stigmas of second bisexual floret sometimes present.
Perianth bristles
not observed.
Nutlet
not present on examined specimens (
Figs. 2
and
4
).
Flowering:
November to May
Distribution and ecology:
Schoenus purpurascens
is a relatively narrow-ranged species of mountainous regions of the southwestern part of the
Western Cape
Provinces of
South Africa
, with its distribution centred mostly around the Caledon region (
Fig. 19
). This species can be found growing on mountain slopes ranging from 275 to over
1000 m
, with moisture regimes varying from moist to well-drained.
Diagnosis:
Schoenus purpurascens
is a species with loose membranaceous leaf sheaths (often with small reddish-purple streaks), non-channelled basal leaf blades (leading to the leaves appearing flat), as well as ovate spikelets (<
4.1 mm
long) with relatively short mucros.
Schoenus bolusii
also has membranaceous leaf sheaths with reddish-purple streaks (
Fig. 13A
); however, the leaf blades of the two species differ, as those of
S. purpurascens
are most often not channelled and thus appear flat compared to the channelled, terete leaf blades of
S. bolusii
. In addition,
S. purpurascens
has ovate spikelets (
Fig. 4P
), whereas those of
S. bolusii
are between lanceolate to ovate in shape.
Schoenus calceolus
and
S. prophyllus
also have ovate spikelets; however, those two species do not have the non-channelled leaves of
S. purpurascens
.
Additional collections examined
South Africa
.
WESTERN CAPE
:
3418 (Simonstown):
River Zondereinde Mts.
, (–BD),
Apr 1930
,
Stokoe 2163
(
BOL
)
;
Oudebos, RiverZonderEnd Mts., (–BD),
May 1930
,
Stokoe 2100 c
(
NBG
)
;
Riviersonderend Mtns., (–BD), Apr or
May 1950
,
Stokoe 68,118
(
NBG
)
;
Kogelberg Forest Reserve, N.E.
side of Pringle Peak along path, (–BD),
12 May 1969
,
Boucher 304
(
NBG
)
;
Kogelberg Forest Reserve
, Paardeberg, 30̊ side of kloof facing S.W. on summit of Paardeberg, (–BD),
25 Feb 1970
,
Boucher 1155
(
NBG
)
.
3419 (Caledon):
Grabouw Forest Reserve
,
Valleiberg, E.
slope, (–AA),
20 May 1969
,
Stehle 96
(
NBG
)
;
Lebanon
State Forest
,
Jakkalsrivier Catchment Id.
, (–AA),
12 Apr 1972
,
Haynes 615
(
NBG
)
;
Lebanon
State Forest
,
Jakkalsrivier Catchment Ib.
, (–AA),
26 Mar 1973
,
Haynes 785
(
NBG
[2 sheets])
;
mountains above Kleinmond, (–AC),
1 Apr 1934
,
Stokoe 2694
(
BOL
)
;
Babylon's Tower, on steep peaty S. slopes of ridge and also among rocks on upper slopes, (–AC),
16 Nov 1969
,
Esterhuysen 32,322
(
BOL
, K)
;
Schilpadkop area
, above
Happy Valley
,
R.Z.E. Mts.
, (–AD),
30 Nov 1952
,
Esterhuysen 20,795
(
BOL
, K),
Esterhuysen 20,796
(
BOL
, K)
;
Schilpadkop,
R.Z.E. Mts.
, near Greyton, marshy S. slope, above
Happy Valley
, (–AD),
2 Jan 1953
,
Esterhuysen 21,038
(
BOL
, K)
;
Hermanus,
Fernkloof Nature Reserve
, (–AD),
5 Mar 1974
,
Orchard 65
(K,
NBG
)
;
Rivier Zonder Einde Mts.
, near ZonderEnd, (–BA),
16 Jun 1949
,
Wilman 505
(
BOL
)
;
Kleinmond, (–BD),
Apr 1930
,
Stokoe s.n.
(
SAM
)
;
Kogelberg,
Harold Porter
N.R.
,
Leopards Kloof, W.
of waterfall, (–BD),
4 Aug 2017
,
Helme 9207
(
BOL
,
MT
,
NBG
)
.