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
2.
Schoenus graminifolius
(Levyns)
T.L.Elliott & Muasya, S.
African J. Bot.
112: 359 (2017).
Tetraria graminifolia
Levyns, J. S.
African Bot.
13: 85 (1947)
.
Type
:
South Africa
,
Western Cape Province
, 3318 (
Cape
Town
):
Lion's Head
, western slopes, (–CD),
29 Jul 1946
,
Levyns
7917
(BOL!, holo. [
BOL139426
]).
Caespitose, phyllopodic perennial graminoid.
Culms
terete, 290–650 ×
0.6–1.4 mm
.
Leaves
basal, up to height of culm, 2–5, (150–)283–410 × 0.2–0.6(—1.9) mm, usually straight, proximally channelled or not, margin serrate above sheath.
Sheaths
firm, reddish-brown but paler above, longitudinally striate.
Ligule
ranging from scarcely membranaceous to membranaceous with small reddish-purple streaks, 2-lobed, varying in length, (0.5–)1.1–2.5(—5.6) mm long.
In
fl
orescence
a contracted pseudolateral panicle, 20–39 ×
7–15 mm
, proximal rachis length usually relatively short, (1–)
4–15 mm
.
Proximal primary in
fl
orescence bracts
sometimes channelled proximally, apex acute to acuminate, widened at base,
90–165 mm
long, exceeding length of inflorescence up to several times, notable longitudinal veins. Proximal and subproximal primary inflorescence bracts with membranaceous extensions at base.
Spikes
2–5, (3.0–)7.0–
19 mm
long, overlapping.
Spikelets
lanceolate, 5.2–7.1 ×
1.1–1.4 mm
, pedicellate, 2–11 spikelets per spike, membranaceous or chaffy in texture.
Proximal spikelet prophyll
often indistinguishable from lower glumes, with a raised vein extending to mucro, 1.4–3.0(— 4.4) mm long, chaffy, prophyll mucro
1.3–3.6 mm
long.
Rachilla
0.1–2.4 mm
long.
Glumes
4–7 per spikelet, proximal glume relatively long, (2.0–)
3.4–4.4 mm
long, subproximal glume
3.6–5.3 mm
long, upper glumes longer than basal ones, apex obtuse. Glume mucros absent or short, proximal mucro
0.1–1.6 mm
long, subproximal mucro 0.1–0.4(—1.7) mm long, lower glumes and mucros usually over half the length of spikelet.
Stamens
(2–)3(—4) per floret, anthers not measured due to lack of specimens at anthesis.
Stigmas
3-branched, vestigial stigmas of second bisexual floret not observed.
Perianth bristles
about half the length of nutlet.
Nutlet
broad elliptic, trigonous, yellowish in colour, 1.4–2.3 × 1.0–
1.1 mm
.
Nutlet beak
, 0.3–1.0 mm long, hispid (
Figs. 2
and
3
).
Flowering:
Flowering specimens not observed, but fruiting occurs from July to November
Distribution and ecology:
Schoenus graminifolius
has been collected from slopes on Lion's Head and Chapman's Peak on the
Cape
Peninsula (
Fig. 8
). This species has been mostly found on granitic soils at elevations greater than
120 m
.
Diagnosis:
The spikelets of
S.graminifolius
differ from other species in the group as the glumes are papery (or chaffy) with reddish-purple streaks throughout and the apices are usually obtuse. The glumes of the other species in this group are firmer (see
Fig. 3
), without distinct reddish-purple streaks throughout. The primary inflorescence bracts of
S. graminifolius
are conspicuously widened at the base, which is similar to
S. auritus
; however, the notable differences in the glumes can be used to distinguish the two species from each other.
Additional collections examined
South Africa
.
WESTERN CAPE
:
3318 (
Cape Town
):
W. slopes below
Lion's Head
, (–CD),
Oct 1946
,
Levyns
8092
(
BOL
,
K
,
SAM
);
Signal Hill
, circular path below Lion's Head, N.W.-facing aspect above
Clifton
, (–CD),
5 Nov 2005
,
Verboom
905
(
BOL
);
c.
600 m
from
Signal Hill Rd.
along hiking path to
Lion's Head
, at least
100 m
away from large granitic outcrop, (–
CD
),
15 Nov 2017
,
Elliott
&
Laidler
TE2016_282
(
BOL
),
Elliott
&
Laidler
TE2016_283
(
BOL
).
3418 (
Simonstown
):
Chapmans
peak drive, just before the day pass turn around point, below the road, permanent monitoring site # 11, (–AB),
25 Jan 2017
,
Euston-Brown
5194
(
MT
).