A taxonomic revision of the genus Pauridia (Hypoxidaceae) in southern Africa
Author
Snijman, Deirdre A.
Compton Herbarium, South African National Biodiversity Institute, Private Bag X 7, Claremont 7735, South Africa / Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park, Johannesburg, 2006, South Africa;
d.snijman@sanbi.org.za
text
Phytotaxa
2014
2014-10-14
182
1
1
114
journal article
10.11646/phytotaxa.182.1.1
1179-3163
8307173
22.
Pauridia monticola
Snijman
,
sp. nov
.
Fig. 35
New species most similar to
Pauridia affinis
in the firm-leaved habit, but distinguished by corm fibres reticulate in distal half, by somewhat compressed terete or canaliculate, often broader leaves, 1.5–6.0(–13) mm versus 1.5–2.0(–3.0) mm wide, by a predominantly 2- versus 1-flowered inflorescence, and by a shorter, narrowly obconical capsule,
5–10 mm
versus
10–12 mmlong
.
Type:
—
SOUTH AFRICA
.
Western Cape
: (Worcester):
Steenboksberg
, ridge Wof car park in wet sandy hollows [QDS: 3319
CA
],
29 August 1965
,
H.C. Taylor
6436
(
holotype
,
NBG
!; isotype,
PRE
!)
.
Plants 2.5–14(–20) cm tall. Corm ovoid,
6–15 mm
diam., covered with dark brown fibrous tunics; fibres hard, linear proximally, reticulate in distal half, firmly attached to flat or convex basal disc, tips acute, erect to slightly spreading; roots slender, arising near corm base between fibres, contractile roots often developing proximally. Cataphylls membranous, up to
25 mm
long, apex oblique. Leaves 2–6 at flowering, sheathing at base up to
20 mm
long or rarely non-sheathing, suberect to slightly arched, linear to narrowly lorate, 40–170 × 1.5–6.0(–13) mm, shallowly canaliculate to compressed terete, firm, pale to dark green, narrowing to a flattened, thin-textured base, epidermis somewhat papillate, margin often raised, frequently with widely spaced, irregularly-shaped, multicellular teeth towards base; apex subacute, often developing a dark, thickened, U-shaped scar when cut or broken. Inflorescences 1 or rarely
2 in
flower at a time, (1)2-flowered, shorter to longer than leaves; scape (5–)10–33(–70) × ca.
1.5 mm
, compressed adaxially, green to pale reddish; bracts 2, clasping pedicels for up to ca. ¾ of length, lanceolate, canaliculate, 13–33 × 1.5–3.0 mm, firm to leathery, green, margin somewhat membranous, apex slightly carinate, spreading, sometimes bearing a few, erect trichomes. Flowers pedicellate, stellate, yellow or white with a large yellow centre, backed with pale green or pale red on outer tepals, unscented; pedicels erect to slightly spreading, deflexed sideways when fruiting, 20–90 ×
0.8–1.3 mm
, green to reddish; tepals 6, lanceolate to narrowly elliptic,
6–17 mmlong
, outer 2.5–5.0 mm wide, mucronate, inner
1.5–3.5 mm
wide. Stamens 6, suberect to slightly spreading, equal or rarely outer shorter than inner, yellow; filaments inserted on ovary rim, outer
0.5–2.5 mm
long, inner 1.0–
3.5 mm
long, both whorls shorter or rarely slightly longer than anthers; anthers oblong,
2–6 mm
long, latrorse, basal lobes ca.
0.5 mm
long; pollen yellow. Ovary narrowly obconical, 2.5–6.0 × 2.0–3.0 mm, 3-locular, green to red; style 1.0–
2.5 mm
long; stigma branches suberect, oblong, 2.0–4.5 ×
0.5 mm
, shorter than or rarely equalling stamens, yellow, densely papillose. Capsules narrowly obconical, 5–10 ×
2–3 mm
, somewhat curved, dehiscence circumscisile and then lengthwise close to septa, placental ridges remaining attached in a central column. Seeds ellipsoid, ca.
0.5 mm
diam., rusty brown, colliculate, epidermal cells arranged in ca. 25 close-set, longitudinal rows, anticlinal cell walls mostly isodiametric, outer periclinal cell walls almost entirely hemispherical. Flowering period: (June–)July–October(–January).
FIGURE 35
.
Pauridia monticola
subsp. monticola
.
A
, whole plant;
B
, corm in detail;
C
, leaf margin in lateral view;
D
, leaf in transverse section;
E
, two outer stamens;
F
, two inner stamens;
G
, style and stigma branches;
H
, ovary in transverse section;
I
, capsule;
J
, seed. Scale bar A = 15 mm; B = 10 mm; C = 0.25 mm; D = 0.5 mm; E–H = 2 mm; I = 3 mm; J = 0.5 mm. Drawn by Nicci Page-Cairns from
Snijman 2046
(NBG!).
Distribution and habitat
:—This species is restricted to the sandstone mountain chain of the Northern and
Western Cape
, extending from the Bokkeveld Mountains near Nieuwoudtville to the Slanghoek Mountains near Worcester, invariably in seasonally wet places (
Fig. 36A
).
FIGURE 36
. Distribution maps for
A
,
Pauridia monticola
subsp.
monticola
(dots) from Northern and Western Cape;
P. monticola
subsp.
nubigena
(triangle) from Northern Cape;
B,
P
.
affinis
from Western Cape, South Africa.
Distinguishing characters and variation
:—Typical
Pauridia monticola
has hard, thick-textured leaves, which are shallowly canaliculate to somewhat dorsiventrally flattened, without a keel, and the margin often has widely spaced, recurved, multicellular teeth. When cut, the leaves readily exude mucilage and develop a thick, dark U-shaped scar where damaged. The inflorescence bracts clasp the pedicels for about three quarters of their length and although membranous-edged in the lower three quarters they are otherwise thick-textured and inconspicuously nerved. Afew erect trichomes often occur distally on the median keel. The narrow-leaved specimens of
P. monticola
have often been confused with
P. affinis
, and in earlier synopses of the genus the species was treated as part of a widely circumscribed
P. affinis
(
Goldblatt & Manning 2000
,
Manning
et al.
2002
,
Manning & Goldblatt 2012
).
P. affinis
differs in having terete to hemiterete leaves, most often a one-flowered inflorescence, and capsules of more than
10 mm
, rather than
10 mm
or less as in
P. monticola
.
Anotable set of divergent populations occurs on sandstone pavement on the Bokkeveld Escarpment. These consist of plants with somewhat larger flowers than those from elsewhere, the tepals being
10 mm
long or more, and the flowers are often white with a yellow centre, although plain yellow flowers are also known. Because of the small overlap between these northern populations with those lying further south and the comparatively small degree of difference between them relative to that between the species within
Pauridia
, I treat the larger-flowered, northern populations from the Bokkeveld Escarpment as a separate subspecies of
P. monticola
.
Key to subspecies
1. Leaves linear to narrowly lorate, shallowly canaliculate, 40–170 × 1.5–6.0(–13) mm; flowers yellow, tepals
6–10 mm
long, outer tepals 2.5–4.0 mm wide ..............................................................................................................
subsp.
monticola
- Leaves linear, compressed terete, 35–90 ×
1.5 mm
; flowers yellow or white with a large, yellow centre, tepals
10–17 mm
long, outer tepals 4.5–5.0 mm wide ..............................................................................................................
subsp.
nubigena