Talinella boiviniana Baill.

Applequist, Wendy L., 2005, A revision of the Malagasy endemic Talinella (Portulacaceae), Adansonia (3) 27 (1), pp. 47-80 : 57-58

3. Talinella boiviniana Baill.

Bull. Mens. Soc. Linn. Paris 1 (72): 569 (1886). — Type: Boivin 2576, Madagascar, Prov. Antsiranana, Baie de Diégo-Suarez , fl., Dec. 1848 (holo-, P!) .

Shrub to 3 m high with sarmentose branches, sometimes appearing lianoid; bark greenish brown to gray, sometimes with prominent lenticels. Twigs straight to somewhat crooked, with few or no lenticels, glabrous, dark brown to ruddy or dull olive, often with peeling waxy outer layer. Leaves broadly elliptical or obovate to rarely suborbicular, 2.0- 6.5 cm long, (1.5-)2.0-4.0(-5.0) cm broad, occasionally asymmetrical, glabrous; apex rounded to emarginate, acute or short-apiculate; base tapering, somewhat concave; margins entire or slightly undulate; midrib conspicuous, secondary venation not visible or barely visible. Inflorescences terminal or lateral, the largest at maturity up to 20(-30) cm long and 15 cm wide, usually broadly to narrowly ovoid to oblong, with numerous maturing flowers; peduncle and rachis sturdy, glabrous; bracts (0.5-)0.7-2.0(-2.5) mm long, linear to narrowly triangular or triangular in the smallest, apex brown-tipped or pale. Dioecious, rare flowers possibly hermaphroditic. Pedicel 2.0- 4.5 mm long. Sepals 2-2.5 mm long, orbicular, usually thickened, sometimes bullate. Petals (3-)5, 2.2-4.0 mm long, whitish to cream, pale green or yellowish, with varying degrees of petal fusion; single petals oblong, often hooded, sometimes borne directly inside another petal; apices of lobes of fused petals sometimes acute; female flowers with smaller petals (2-3 mm). Stamens largely enclosed within petals, attached to ring-shaped nectary disk; inner filaments 3- 4 mm long, the lower two-thirds heavily ciliate and cohering, the upper portion filiform and lax; anthers pale, c. 0.35-0.40 mm long; pollen yellow, released before anthesis. Male flowers with small deep pink ovary. Female flowers with sterile, purplish staminodes, green ovary; stigma branches at maturity (2-)3, c. 0.8-1.1 mm long, nearly sessile and rarely persisting; some female flowers with ovary enlarging in young buds, elliptical and rugose, the stigmas small (<0.2 mm), appressed. Fruit bacciform, green, globose, 6- 8 mm in diameter; remnants of calyx often persisting on developing fruit; seeds (1-)3-4(-6), 2.4- 2.8 mm long, broadly reniform to suborbicular, papillate.

Talinella boiviniana occurs in the extreme north of Madagascar, where it has been observed primarily in two areas, one from the Bay of Diégo Suarez to Orangéa and the other in the vicinity of Lac Sahaka, farther south along the eastern coast. Collections from the Ankarana reserve, previously identified as T. boiviniana , are segregated here as T. ankaranensis (see above). Collections from the region of Lac Sahaka are described as lianoid by label data; while this may not be technically accurate, the southeastern population appears to be more strongly sarmentose, and to have larger leaves and often longer, narrower lateral panicles. The sepals of T. boiviniana are usually thickened, and may present a lumpy or bullate appearance. Hand sectioning of a rehydrated thickened sepal sometimes releases globular clear, cohesive gelatinous blobs, indicating that the observed bumps are glands probably containing some mucilaginous substance of unknown function; this character has not been observed in any other species.

DISTRIBUTION. — Talinella boiviniana is known only from extreme northern Madagascar ( Fig. 4 ). It is restricted to sites near sea level, usually on sand, once reportedly on calcareous substrate at a mostly sandy locality.

CONSERVATION STATUS. — Provisional IUCN Red List Category: Vulnerable (VU D2). Known collections come from only three locations, with most collections from the areas around Orangéa and Lac Sahaka; area of occupancy is estimated at 12 km 2. However, T. boiviniana is flourishing in both of these subpopulations, the latter of which was discovered only recently. More thorough field work along the northeastern coast might reveal a wider distribution.

MATERIAL EXAMINED. — MADAGASCAR: Prov. Antsiranana: Applequist et al. 153, forêt d’Orangéa , along path, sandy soil, 12°14’05”S, 049°21’38”E, 30 m, fl., 17 Jan. 2003 ( MO, P, TAN) ; Applequist et al. 154, same locality, fl., 17 Jan. 2003 ( MO, P, TAN) ; Applequist et al. 160, same locality, fl., 17 Jan. 2003 ( MO, P, TAN) ; Applequist et al. 167 ,

same locality, fl., 17 Jan. 2003 ( MO, P, TAN); Applequist et al. 170 , same locality, fr., 17 Jan. 2003 ( MO, P, TAN); Boivin 2576, Baie de Diégo-Suarez ,

fl., Dec. 1848 ( P) ; Cours & Humbert 5428, District de Diégo-Suarez, Orangéa, roches calcaires, 12°15’S, 049°23’E, fl., 22 Jan. 1960 ( P) ; Humbert & Cours 32237, environs de Diégo-Suarez, forêt d’Orangéa, forêt tropophile sur calcaire et sable, 1-100 m, 12°15’S, 049°23’E, fl., 22 Jan. 1960 ( P, K, MO, G) ; McPherson et al. 18856, 40 km N of Vohémar, near N end of Lac Sakaha, Firaisana: Nosibe, Fokontany: Anjiabe, littoral forest on sand, 13°04’45”S, 049°54’17”E, 20 m, fl., 3 Nov. 2002 ( MO) ; Rabenantoandro et al. 1311, Fivondronana : Vohémar , Firaisana : Nosibe , Fokontany : Anjiabe , village le plus proche: Anaborano près du lac Sahaka , forêt littorale sur sable d’Anaborano (Analabe), 13°04’43”S, 049°54’04” E, 10 m, fr., 23 Feb. 2003 ( MO) ; Rabenantoandro et al. 1330, Fivondronana : Vohémar , Firaisana : Nosibe , Fokontany : Anjiabe , forêt littorale sur sables d’Analabe (Anaborano) près du lac Sahaka, 5 m, 13°04’53”S, 049°54’03”E, fl., 25 Feb. 2003 ( MO) ; Rabevohitra et al. 4501, Fivondronana : Vohémar , Commune rurale: Nosibe, forêt sublittorale d’Analabe sur sables blancs, 13°04’45”S, 049°54’17”E, fr., 22 Feb. 2003 ( MO, TAN) ; Rogers et al. 158, Orangéa, c. 1.5 km NE of military camp on sandy road along trail to ocean, 12°14’18”S, 049°21’49”E, 20-75 m, fl., 15 Feb. 2003 ( MO) ; Rogers et al. 159, Orangéa, same locality, fr., 15 Feb. 2003 ( MO) ; Service Forestier ( Capuron ) s.n., district de Diégo- Suarez, Orangéa, 12°15’S, 049°23’E, fl., s. date ( TEF) .

Figures

FIG. 4. — Distributions of Talinella species from the extreme north: T. ankaranensis (●), T. boiviniana (▲), T. pachypoda ($).