Three new species and one new subspecies of Euryops (Asteraceae: Senecioneae) from the Klein Karoo in the Western Cape Province, South Africa.
Author
Vlok, J. H. J.
text
South African Journal of Botany
2020
2020-09-30
133
167
173
http://dx.doi.org/10.1016/j.sajb.2020.07.025
journal article
286104
10.1016/j.sajb.2020.07.025
108593c9-fd23-4fa7-80b2-61df903bb150
1727-9321
10496796
3.1.
Euryops dasyphyllus J.H.J.Vlok,
Sp. nov
ePagEuryops dasyphyllus B.Nord. & Vlok
ms.(
Manning and Goldblatt, 2012
)
Type:
South Africa
,
Western Cape Province
, Ladismith (3320):
Anysberg Nature Reserve
, about
10 km
west of
Touwsfontein
house, (-CB),
650 m
,
19 May 1989
,
J.H.J.Vlok
2121
(
NBG
, holo.;
S
,
PRE
,
iso
.)
.
Single-stemmed, divaricately branched shrub up to
60 cm
tall; young branches densely leafy, leaves persisting a maximum of two years on a branch.
Leaves
erect with tips spreading, 6—16 X
1 mm
, simple, terete with deep, narrow groove adaxially, acuminate with a small, reddish-brown mucro, lanate-pubescent with white, dendritic trichomes.
Peduncles
terminal, solitary,
90—260 mm
long, ca.
1 mm
thick, reddish-brown.
Involucre
widely cup-shaped,
8—10 mm
diam.
Involucral bracts
uniseriate, 11 or 12 glabrous, limbs connate for ca. half their length, lanceolate, 6—7 X
2—3 mm
, 3-veined, membranous along upper margin, minutely ciliate-puberulous towards acuminate tip.
Ray
fl
orets
8 to 10; corolla yellow, tube cylindrical,
2 mm
long; lamina oblong,
10—12 mm
long, 5-veined; style branches recurved, ca.
1 mm
long.
Disc
fl
orets
40 to 50; corolla yellow,
5—6 mm
long; tube cylindrical,
2—3 mm
long; limb campanulate,
3—4 mm
long, with triangular-acute lobes.
Anthers
2 mm
long with lanceolate appendage.
Style
terete with base swollen, style branches recurved, ca.
1 mm
long.
Pappus
0.
Cypselas
obovate, ca. 1.0 X
0.75 mm
, tuberculate, surface densely covered with minute white papillae; ridges not prominent. (
Fig. 1
;
Plate 1
).
Flowering period
: May. Plants respond rapidly to rain and flower within three weeks after rain. Flowering may thus depend on rainfall events, rather than the season.
Distribution and ecology:
Euryops dasyphyllus
is known only from the Ladismith district where it occurs in Succulent Karoo vegetation, more specifically in the Western Little Karoo vegetation unit
sensu
Mucina and Rutherford (2006)
. At a finer scale
Vlok and Schutte-Vlok (2015)
described this vegetation as Scholtzbosveld, a vegetation unit in which
Pteronia pallens
L.f. is the dominant species.
E. dasyphyllus
occurs on a small plateau in dry, clayey soil with some calcrete and quartz pebbles on the surface. It is locally abundant, but populations are localised.
Diagnosis:
Euryops dasyphyllus
belongs to sect.
Psilosteum
as the ray and disc florets lack pappus bristles. It is unique in this section in having simple, entire and lanate-pubescent leaves. Its affinities within the group are not clear but it is most similar to
E. anthemoides
B.Nord.
and
E. tenuilobus
(DC.) B.Nord.
, but these two species differ in having lobed leaves and they do not occur in the Klein Karoo.
Conservation notes:
Despite several searches this species was only observed in a similar habitat about
3 km
south-east of the
type
locality (
Fig. 3
). Part of the
type
locality was severely disturbed when the area was previously ploughed to establish Old-man Saltbush (
Atriplex nummularia
). Following
Raimondo et al. (2009)
,
I
propose a conservation status of Endangered (
B2
(a) & (b)) for this species.
Fig. 1.
Euryops dasyphyllus
, drawn from the type specimen. A, flowering branch; B, ray floret; C, disc floret; D, anther; E, style branches of disc floret; F, mature cypsela. Artist: Tin Sj¨oberg.
Etymology
: The specific name alludes to the woolly hair on the leaves.
3.1.1. Changes to species key
This species can be accommodated in the existing key to sect.
Psiloteum
(
Nordenstam, 1968: 325
) by changing couplet 20 to the following:
(i) Leaves densely hairy...
E. dasyphyllus
(ii) Leaves glabrous... continue with existing key.