A revision of the Malagasy endemic Talinella (Portulacaceae)
Author
Applequist, Wendy L.
text
Adansonia
2005
3
27
1
47
80
journal article
http://doi.org/10.5281/zenodo.5370864
1639-4798
5370864
9.
Talinella microphylla
Eggli
Adansonia sér. 3, 19: 56 (1997)
. —
Type
:
Humbert
20221
,
Madagascar
, Prov.
Toliara
, environs du lac
Tsimanampetsotsa
(côte
SW
)
,
bush xérophile des côteaux et plateaux calcaires rocailleux,
2-200 m
, fl., fr.,
14 Feb. 1947
(holo-,
P
!; iso-,
P
!,
MO
!,
K
!,
G
!)
.
Shrub with sarmentose to lianoid branches, to
2 m
high, sometimes appearing lianoid. Twigs straight to contorted; bark on larger twigs sometimes cracked or peeling, pale grayish or dull brown, glabrous; lenticels absent or small; leaves and inflorescences often borne in small clusters on short shoots. Leaves oblong to obovate, the lateral margins deeply revolute so that the blade appears to be narrowly oblong, <
10 mm
long, appearing <
2 mm
broad, to twice that width when unrolled, thick or succulent, sometimes purple-tinged; apex truncate to minutely mucronulate or emarginate or rounded; base tapering; midrib conspicuous beneath. Inflorescences usually lateral on short shoots, small and fewbranched, each branch cymose with 1-2(-3) fertile flowers and few bracts; peduncle and rachis filiform, weakly white-papillose to glabrate; bracts 0.3-0.7(-1.5) mm long, pale with dark tip. Possibly gynodioecious. Pedicel
1-7 mm
long, sparsely papillate to glabrate. Sepals
1.7-2.3 mm
long, greenish to greenish-white. Petals 2, in hermaphroditic flowers 2.5-3.2(-4.0) mm long, white to greenish white. Stamens white; filaments
2.2-2.5 mm
long, the base of the inner whorl papillose or short-ciliate; anthers (0.4-)
0.5- 0.7 mm
long, broadly elliptical. Stigma branches 2-3,
1.4-2.5 mm
long, slightly flattened, slightly papillose, dull pink; style
0.8-1.2 mm
long; ovary green, globose. Immature fruit globose, to
4.5 mm
in diameter, with remnants of calyx and staminodes persisting for some time; mature fruits not known.
FIG. 10. — Distribution of
Talinella microphylla
(●) and
T. xerophila
(
$
).
Talinella microphylla
as originally circumscribed was a rather heterogeneous assemblage of small-leaved, often gnarled plants from the most arid habitats at the western and southern edge of the range of
T. grevei
; the available specimens can be divided morphologically into those from Lac Tsimanampetsotsa, south of Tuléar, and those from further to the south and east, which are described herein as
T. xerophila
Appleq.
Talinella
20°S
21
22
23
24
25
44 45 46
47°E
microphylla
sensu stricto
can be distinguished by its very small, strongly revolute leaves, glabrous twigs, and whitish flowers with two petals. Like
T. grevei
, to which it is probably most closely related,
T. microphylla
appears to be gynodioecious.
Talinella grevei
subsp.
calcicola
has been collected near Tsimanampetsotsa (
Perrier de la Bâthie 19043
), where, despite being rather underdeveloped, it can be distinguished from
T. microphylla
by its larger leaves and sturdier inflorescences. Furthermore,
T. microphylla
has pale petals, whereas
T. grevei
has deep pink petals.
DISTRIBUTION. —
Talinella microphylla
is known only from the vicinity of Lac Tsimanampetsotsa in southwestern
Madagascar
(
Fig. 10
), on limestone substrates at low altitudes (<
200 m
).
V E R N AC U L A R N A M E S. — Dr a k yd r a k y (i n Mahafaly;
Humbert
20229
).
CONSERVATION STATUS. — Provisional IUCN Red List Category: Vulnerable (VU D2).
Talinella microphylla
occurs in only one known location, around Lac Tsimanampetsotsa;
although this area is protected, it remains vulnerable to natural threats.
MATERIAL EXAMINED. —
MADAGASCAR
:
Prov.
Toliara
:
Bosser
15737
, plateau calcaire, RN 10,
Lac Tsimanampetsotsa
, fr.,
Feb. 1962
(
P
,
TAN
,
MO
,
K
)
;
Humbert
20221
, environs du lac
Tsimanampetsotsa
(côte
SW
)
,
bush xérophile des côteaux et plateaux calcaires rocailleux,
2-200 m
, fl., fr.,
14 Feb. 1947
(
P
,
K
,
MO
,
G
)
;
Humbert
20229
, same locality, fl., fr.,
14 Feb. 1947
(
P
,
MO
)
;
Keraudren
1405
, sur les calcaires de la RN 10 au-dessus
du Lac Tsimanampetotsa
, fr.,
Feb. 1962
(
P
)
;
Phillipson
2737
,
Tsimanampetsotsa Reserve
S
of Tuléar
,
N
edge of reserve,
24°04’S
,
043°45’E
,
80 m
, fl.,
28 Dec. 1987
(
P
,
MO
,
TAN
)
.