Six new species of Ruschieae (Aizoaceae) and further notes in Ruschia
Author
Klak, Cornelia
Author
Hanáček, Pavel
Author
Bruyns, Peter V.
text
South African Journal of Botany
2023
2023-05-31
156
144
161
http://dx.doi.org/10.1016/j.sajb.2023.02.035
journal article
57639
doi.org/10.1016/j.sajb.2023.02.035
ec74f8c7-0d1d-4ad7-b9d7-3acab1c23ec2
8120978
1
Ruschia rupestris Klak
sp. nov.
(
Fig. 8
)
Type:
South Africa
,
Western Cape
,
5 km east
of
Seweweekspoort
on road to
Bosluiskloof
(-AD),
1110 m
a.s.l.,
3 Apr 2021
,
Klak
2854 (
BOL
,
holo
, barcode:
BOL0232474
)
.
Diagnosis: Differs from
Ruschia altigena
by a more upright habit and height of
15-25 cm
(prostrate and <
15 cm
tall in
R. altigena
). In addition, in
R. rupestris
endocarpal closing bodies are missing and the placentas form broad open hoods (only small closing bodies present in
R. altigena
).
Clump-forming dense succulent shrub
15-25 X 30-50 cm
, with some prostrate branches and with erect flowering branches, basal part very woody, to
9 mm
diam, internodes
4-15 X ± 4 mm
, black or grey. Leaves opposite, trigonous, with rounded keel, tips pointed, dark, dirty green, spreading, fused into a sheath to
9 mm
long, sheath without a line, 12-25 (-36) mm long,
4-6 mm
broad and thick, old, blackened leaves drying up and persisting on plant for several years. Flowers solitary,
15-20 mm
diam., pedicels short,
6-8 mm
long, bracts at base of pedicel, to 4 X ±
1 mm
, sepals
5.7-10 mm
long, subequal, slightly succulent, without membranous margins; petaloid staminodes magenta, 2-3-seriate, ± same length,
6.5-9 X 0.7-0.9 mm
, lanceolate to obtuse, filamentous staminodes few, collected in the center and about the same length as the stamens, 4.5-5.0 X
0.1-0.2 mm
; stamens numerous, outer stamens ±
5 mm
long, in 4-5 rows, papillate at base, pollen white; stigmas 5, short,
3.2-3.5 mm
long, yellowish, top of ovary raised in the center to ±
1.2 mm
; nectary forming green, crenulated ring. Capsule 5-locular,
6-8 mm
diam., top raised to
2 mm
, with low rims, lower part
4 mm
deep and top-shaped, covering membranes firm, with inconspicuous ridge below, keels slender, widely separated at their bases, slightly lacerated in upper parts, long so that valves open into a horizontal position, closing bodies absent, placenta forming broad open hood detached at the top and from which funicles arise, valve wings absent. Seeds ochre, finely colliculate to almost smooth,
0.6-0.7 X 0.5-0.6 mm
.
Fig. 9.
Lampranthus umbraticola
. A. Habit. B. Flowers. C. Side view of open (l) and top view of open fruit (r). D. Seeds.
3.1.19. Distribution and ecology
The species is known from the Montagu and Ladismith districts (
Fig. 4
), on sandstones of the Witteberg-Series, either on lower slopes or on flat rocky areas, typically in the transitional area from sandstones to shales. These spots, at altitudes from
820 to 1060 m
a.s.l, are rich in other succulent species. Flowering occurs from November to December.
3.1.20. Distinguishing features and relationships
Ruschia rupestris
is closely allied to
R. altigena
. The two species differ in their habit:
R. rupestris
forms cushions with some prostrate branches and with erect flowering branches to
25 cm
tall (
Fig. 8A, B
), whereas older plants of
R. altigena
form dense, spreading mats (
Fig. 8C
), where the flowering branches are less than
15 cm
tall.
Ruschia altigena
occurs at higher altitudes, from ±
1300 to 1700 m
a. s.l., on rocky sandstone outcrops within fynbos, where few other succulents are found.
Ruschia karrooica (L.Bolus) L.Bolus
, which is known from Matjiesfontein, near Laingsburg, may be a further close relative. The latter species has an erect habit, but shares the highly fused leaves, solitary flowers and broad open hoods, instead of closing bodies.
3.1.21. Etymology
The epithet refers to the rocky habitats to which the species is confined.
3.1.22. Conservation status
Due to its preference for rocky habitats which are not arable, the absence of any mining activities in the area and the relatively wide occurrence, we suggest a status of Least Concern (LC).
3.1.23. Additional specimens investigated
South Africa
.
WESTERN CAPE
: 3320 (
Montagu
):
Witteberg
, north aspect (-BC),
10 Nov. 1935
, ±
3000 ft
,
F.M. Leighton
s.n. (
BOL
, barcode
39865
)
;
Farm Varsbokkraal
, entrance to
Zuurkloof
(-BD),
857 m
a.s.l.,
4 Apr 2021
,
Klak
2865 (
BOL
)
;
9 Aug 2013
,
Bruyns
12585 (
BOL
)
;
3321 (
Ladismith
):
Farm Vleiland
, entrance to kloof (-AC),
820 m
a.s.l.,
26 Jun 2021
,
Klak
2871 (
BOL
)
;
Bosluiskloofpass
(-AD),
1054 m
a.s.l.,
2 Sep 2008
,
Klak
1716 (
BOL
)
;