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 pseudocrassa Klak
sp. nov.
(
Fig. 5
)
Type:
South Africa
,
Northern Cape
,
Kamiesberg
(3018),
Farm Uitval
(-DB),
1 Sep. 2022
,
850 m
a.s.l.,
Bruyns
14124 (
BOL
,
holo
, barcode:
BOL0232476
,
K
iso
)
.
Fig. 4. Distribution of new species of
Ruschia
:
R. variabilis
(circle),
R. pseudocrassa
(triangle),
R. rupestris
(inverted triangle).
Diagnosis: Differs from
Ruschia crassa
by having smooth leaves and erect to tangled branches, whereas leaves are velvety from long papillae and branches are erect in
R. crassa
.
Densely branched succulent shrub,
30-50 X 40-100 cm
, branches erect to tangled, old stems grey and woody, basal part very woody, internodes
14-15 X 6-7 mm
. Leaves opposite, grey, fused into a sheath and clasping the branch, without a line, free parts spreading, somewhat heart-shaped, keeled on the back,
8-10 mm
long,
5.5-7 mm
broad and thick, with inconspicuous tooth, epidermis smooth, with dark dots below the epidermal surface. Flowers solitary, white, to
20 mm
diam., sessile, calyx lobes 5, to
5 mm
long, about equal length, 2 slightly succulent, pedicels short, petaloid and filamentous staminodes filiform, in 1-2 rows, petaloid staminodes ±
8 X 0.5 mm
, filamentous staminodes and stamens free to bases, of about equal length and collected into a cone around the centre, some curling backwards, ±
5 X 0.3 mm
, with hair-like papillae, stamens numerous, in 3-4 rows, papillate from middle towards bases, pollen yellow, stigmas 5, feathery, green, ±
4.5 mm
long, top of ovary with raised lobes, nectary in a green, crenulated ring. Capsule 5-locular, ±
9 X 10 mm
, rims raised to
2 mm
, lower part funnel-shaped, covering membranes thick and spongy, with ledge below, keels short, diverging and not touching at bases, only open into an erect position, closing bodies hook-shaped, valve wings absent. Seeds ochre, smooth, 1.1-1.2 X
0.9 mm
, somewhat D- shaped.
3.1.10. Distribution and ecology
This species is widespread across Bushmanland and some of the eastern parts of Namaqualand and is known from the Gamoep, Kamiesberg and Louriesfontein districts (
Fig. 4
). It occurs on gravelly, calcareous or gneissic flats, at altitudes of
750-1000 m
a.s.l. It flowers between August and September.
3.1.11. Distinguishing features and relationships
Ruschia pseudocrassa
forms spreading shrubs
30-50 X 40-100 cm
. The free parts of the leaves are short, and the leaves clasp the stem to form a sheath. Thus, the plants superficially appear to be “stem”-succulents, like members of
Mesembryanthemum subg. Juncea
. There are several largish species in
Ruschia subg. Ruschia
such as
R. grisea
and
R. abbreviata
, which have developed this trait, but these have a less conspicuous, 1-toothed keel on their leaves than is typical for
R. crassa
and
R. pseudocrassa
. In addition, the branches are thicker in
R. crassa
and
R. pseudocrassa
compared to both
R. grisea
and
R. abbreviata
. An important character which distinguishes species in subg.
Ruschia
is whether the leaf-surface is smooth or distinctly papillate.
Ruschia pseudocrassa
and
R. crassa
are similar, particularly in herbarium specimens. However, they can be easily separated by the distinctly velvety leaves of
R. crassa
, which contrast with the much smoother leaves of
R. pseudocrassa
.
Fig. 5.
Ruschia pseudocrassa
. A. Habit. B. Leaves. C. Flowers and fruits. D. Side view of closed (l) and top view of open fruit (r). E. Seeds.
3.1.12. Etymology The epithet refers to its similarity to
Ruschia crassa
.
3.1.13. Conservation status
The species is widespread and the area where it occurs is not arable, except for grazing. As yet, no mining activities are present in this area. For these reasons, we suggest a status of least concern (LC).
3.1.14. Additional specimens investigated
South Africa
.
NORTHERN CAPE
: 2918 (Gamoep):
Kamiesberg
, S of
Paulshoek
(-AD),
5 Oct 2021
,
1000 m
a.s.l.,
Klak
2992 (
BOL
)
;
Bushmanland
, farm
Kouberg
(-CD),
12 Jul 2008
,
930 m
a.s.l.,
Klak
1678 (
BOL
)
;
Gamoep
, farm
Vaalkoei
(-CD),
16 Jul 2021
,
974 m
a.s.l.,
Klak
2896 (
BOL
)
;
3018 (
Kamiesberg
):
At turn-off from Pofadder to Kliprand
,
Farm Boonstevlei 398
(-BC),
21 Aug 1990
,
A. Le Roux
4154 (
NBG
)
;
10 km north
of
Kliprand
(-BC),
4 Aug 2022
,
926 m
a.s.l.,
Klak
3108 (
BOL
)
;
3019 (
Louriesfontein
):
Farm Taaiboshoek
(-CA),
13 June 1999
,
750 m
a.s.l.,
Bruyns
7876 (
BOL
)
;
Calvinia
, along
Brandvlei
road, farm
Witputs
(-DB),
950 m
a.s.l.,
22 Mar 2019
,
Klak
2663 (
BOL
)
;
9 Sep 1999
,
Bruyns
7957 (
BOL
)
.