Talinella microphylla Eggli, 1997

Applequist, Wendy L., 2005, A revision of the Malagasy endemic Talinella (Portulacaceae), Adansonia (3) 27 (1), pp. 47-80 : 73-74

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.

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) .

Figures

FIG. 10. — Distribution of Talinella microphylla (●) and T. xerophila ($).