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
12.
Schoenus calceolus
T.L.Elliott & Muasya
,
sp. nov.
Type:
South Africa
,
Western Cape Province
, 3420 (
Bredasdorp
):
De Hoop Nature Reserve
,
1 km
S
. of entrance gate on W. side of park, near start of bicycle trail, (–AD),
30 Sep 2016
,
Elliott
&
Muasya
TE2016_121
(
BOL
!,
holo
.,
MT
!,
NBG
!,
iso
.)
.
Caespitose, phyllopodic perennial graminoid.
Culms
terete, slender, 273–490 ×
0.2–0.9 mm
, culm bases flattened and held grouped together by a thin sheath.
Leaves
basal, distichously arranged so that base appears flat, 2–4(—7), (36–)65–115(—207) ×
0.2–0.9 mm
, straight, proximally channelled, margin serrate above sheath.
Sheaths
membranaceous and often shredding with age, loosely to firmly clasping the culm and translucent, longitudinally striate.
Ligule
firm, varying lengths,
0.2–2.7 mm
long.
In
fl
orescence
a pseudolateral panicle, 19–40 ×
4–11 mm
, proximal rachis length
4–18 mm
.
Proximal primary in
fl
orescence bracts
slender, brittle, not channelled, apex acute to acuminate, never widened at base,
60–112 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
3–11, 4.0–12.0 mm long, usually dispersed along rachis.
Spikelets
ovate, 2.4–4.0 ×
1.1–1.4 mm
, pedicellate, 2–8 spikelets per spike, reddish-brown sometimes with narrow hyaline margins.
Proximal spikelet prophyll
1 per spikelet, prophylls with a raised vein extending to mucro,
0.3–1.3 mm
long, prophyll mucro
0.8–2.4 mm
long.
Rachilla
0.4–2.8 mm
long.
Glumes
6–8 per spikelet, proximal glume
0.5–1.4 mm
long, subproximal glume
0.5–1.3 mm
long, upper glumes longer than basal ones, apex acute to acuminate. Glume mucros relatively short, proximal mucro
0.1–0.6 mm
long, subproximal mucro
0.2–0.7 mm
long.
Stamens
3 per floret, anthers
1.9–3.3 mm
long.
Stigmas
3-branched, vestigial stigmas of second bisexual floret sometimes present.
Perianth bristles
not observed.
Nutlet
not mature on examined specimens (
Figs. 2
and
4
).
Fig. 21.
Documented locations of
Schoenus calceolus
.
Flowering:
May
Distribution and ecology:
The recorded specimens of
S. calceolus
have been collected from sites below
150 m
in the southern Agulhas Plain region of
South Africa
(
Fig. 21
).
Schoenus calceolus
mostly grows on limestone-derived soils; however, a specimen has been collected from a site on calcrete overlying shale.
Diagnosis:
A unique character differentiating
Schoenus calceolus
from other species in this group is that its culm bases are flat (and sometimes twisted), with several culms grouped or held together by a thin translucent sheath (
Fig. 5
). The spikelets of
S. calceolus
,
S. prophyllus
and
S. purpurascens
are all ovate; however,
S. calceolus
has slender, channelled leaves compared to the wider, often non-channelled leaves of
S. purpurascens
.
Furthermore,
S. prophyllus
has firm, shiny prophylls and relatively long prophyll mucros (> 3.0 mm), whereas
S. calceolus
has less firm and not shiny prophylls, with shorter prophyll mucros (<
2.4 mm
).
Additional collections examined
South Africa
.
WESTERN CAPE
:
3419 (
Caledon
):
Spitzkop, W.
of
Baardskeerdersbos
, (–DA),
26 Apr 1975
,
Oliver
5816
(
NBG
,
PRE
)
.
3420 (
Bredasdorp
):
Vander Stelskraal
, c.
500–1000 m
S.E. of homestead, (–AC),
2 Oct 2016
,
Elliott
&
Muasya TE
2016_128
(
BOL
)
;
De Hoop Nature Reserve
, coastal fynbos on limestone, (–AD),
6 Apr 1976
,
Burgers
147
(
NBG
)
;
De Hoop Nature Reserve
,
5 km
S. of gate, (–AD),
30 Sep 2016
,
Elliott
&
Muasya TE
2016_120
(
BOL
)
;
De Hoop Nature Reserve
,
1 km
S. of entrance gate on W.side of park, (–AD),
30 Sep 2016
,
Elliott
&
Muasya TE
2016_121
(
BOL
)
,
Elliott
&
Muasya TE
2016_122
(
BOL
)
,
Elliott
&
Muasya TE
2016_123
(
BOL
)
;
Duinefontein
farm between
Bredasdorp
and
Skipskop
, near road, (–CB),
2 May 1981
,
Boucher
5035
(
NBG
,
PRE
)
.