Talinella dauphinensis Scott-Elliot

Applequist, Wendy L., 2005, A revision of the Malagasy endemic Talinella (Portulacaceae), Adansonia (3) 27 (1), pp. 47-80 : 59-61

5. Talinella dauphinensis Scott-Elliot

J. Linn. Soc. Bot. 29: 4 (1891). — Type: Scott-Elliot 2717, Madagascar, Prov. Toliara, Fort Dauphin, thickets on sandy soil, 25°03’S, 047°00’E, fl., May (s. year) (neo-, K [photo seen]; isoneo-, P!, here designated).

Small shrub or liana, to 2 m high with sarmentose branches. Twigs straight to crooked, dark reddish to pale brown, usually with plentiful pale elliptical to fusiform lenticels, glabrous or occasionally papillate with white and brown papillae. Leaves broadly elliptical or ovate to narrowly ovate, rarely obovate or broadly lanceolate, 2.50- 7.75 cm long, (1.0-) 1.3-3.3 cm broad, glabrous or visibly bullate, sometimes moderately coriaceous on drying; apex short-apiculate to acute or

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42 43 44 45 46 47 48 49 50 51°E rarely rounded, frequently asymmetrically apiculate; base rounded-tapering; midrib conspicuous at least beneath, secondary venation not visible. Inflorescences terminal, loose, with up to 2-3 dozen buds, few mature flowers, clustered empty bracts; peduncle and rachis filiform, glabrous or occasionally white-papillose; bud scales below inflorescences infrequent, usually small and dark, sometimes recurved, 0.3-1.1 mm; bracts 0.5-0.9- 1.3(-3.0) mm long, narrowly triangular, apical portion or whole bract brown, sometimes with pale tip. Dioecious or possibly gynodioecious, female flowers with antherless staminodes but “male” flowers sometimes with well developed ovaries and stigmas. Pedicel 2-9(-18) mm long. Sepals 1. 0-2.3 mm long, pale green, orbicular, usually unequal, apex rounded. Petals 2-4, 3.0- 4.5 mm long, white to greenish white, often unequal or partly fused, single petals often oblong, convex. Stamens usually reduced to 10- 15, attached to ring-shaped nectary disk; filaments 2. 0-2.3 mm long, pale pink, the lower third or fourth ciliate; anthers yellow, c. 0.7- 0.8 mm long. Stigma branches 2, 1.1-1.8 mm long, terete, irregular at apex, papillose, sessile or on short style especially in “male” flowers. Immature fruit globose.

Talinella dauphinensis has previously been quite broadly defined; most included collections were from the extreme southeastern portion of Madagascar near Fort-Dauphin, ranging from Petriky (on sand at sea level) to the Mandrare River basin (on granite at over 1000 m), with scattered disjunct collections far to the north and northwest of Fort-Dauphin. These specimens share several features, including few-flowered, slender, open inflorescences, twigs often with white and brown papillae, and small whitish or pink flowers; however, when they are separated according to geography and habitat ( Fig. 6 ), correlated morphological differences can be observed. Several segregate species, including T. bosseri , T. humbertii Appleq. , T. latifolia Appleq. , and T. tsitondroinensis Appleq. , are herein described; other species that share the features mentioned and appear to fall into the same group include T. xerophila Appleq. and T. pachypoda Eggli. With the recognition of these taxa as distinct, T. dauphinensis is more narrowly circumscribed here to include plants from sandy soils at low elevations around Fort-Dauphin. It may be distinguished from related species by its broad leaves (often over 5 cm long) with a frequently asymmetrical tip and without visible venation; large inflorescence bracts; small, unequal orbicular sepals; petals whitish and varying from two to four in number; stamens usually reduced in number and attached to a nectar disk; and stigma branches two, terete and often papillose.

EGGLI (1997) did not select a lectotype from among the four indicated syntypes of T. dauphinensis (Scott-Elliot 2972a, 2716, 2551 and 2679). He suggested that the only SCOTT- ELLIOT collection at P, Scott-Elliot 2717, was probably one of the syntypes and that there had been a typographical error in the protologue. However, at the time of writing EGGLI had not seen the material at K, and most of SCOTT- ELLIOT’ s types were deposited at K or BM ( STAFLEU & COWAN 1985). A second duplicate of Scott-Elliot 2717 is one of two SCOTT- ELLIOT specimens at K, the other being Scott-Elliot 2821, and enquiries at BM have not located a specimen numbered 2616, so EGGLI’ s assumption was probably correct. As Scott-Elliot 2717 is the only located probable syntype collection, yet cannot be indisputably proven to be the specimen referred to by SCOTT- ELLIOT (1891), it is here conservatively designated as a neotype rather than a lectotype, a designation that can be overridden should any other syntypes be located.

DISTRIBUTION. — Talinella dauphinensis is known from southeastern Madagascar in the vicinity of Fort-Dauphin ( Fig. 6 ), around Petriky and Vinany Be, in sublittoral or littoral forests or thickets on sand from sea level to <100 m.

CONSERVATION STATUS. — Provisional IUCN Red List Category: Vulnerable (VU D2). Fewer than five locations are known, and all are within a restricted area (estimated extent of occurrence 30 km 2) near the coast, so that a single environmental threat such as a major storm could affect all populations simultaneously.

MATERIAL EXAMINED. — MADAGASCAR: Prov. Toliara: Dumetz & McPherson 1110, Petriky, 25°05’S, 046°52’E, 0-10 m, fl., 5 Dec. 1989 ( MO, TAN); Gereau et al. 3209, Préfecture de Tôlanaro (Fort- Dauphin), Canton de Manambaro, Petriky Forest c. 15 km WSW of Tôlanaro (Fort-Dauphin) on stabilized dune sand, 25°04’S, 046°51’E , 0-10 m, fl., 9 Mar. 1989 ( MO, TAN, TEF); Humbert 20758, forêt de Vinanibe près Fort-Dauphin, forêt ombrophile littorale sur sable siliceux , 5-50 m, 25°03’S, 046°56’E,

fl., 2 Apr. 1947 ( P, MO) ; Humbert 20785, same locality, fl., fl., 2 Apr. 1947 ( P) ; Lowry et al. 5021, Petriky, WSW of Fort-Dauphin along main QMM road, 25°04’25”S, 046°50’15”E, 5 m, fl., 13 Mar 1998 ( P, MO) ; Rabevohitra 2112, Préfecture de Tôlanaro (Fort Dauphin), Petriky, 25°04’S, 046°52’E, 10 m, fl., 12 Jan. 1990 ( TEF) ; Scott-Elliot 2717, thickets on sandy soil, Fort Dauphin , 25°03 ’S, 046°52’E, fl., May (s. year) ( P, K [photo seen]) ; Scott- Elliot 2821, Fort Dauphin , thickets etc. on white sand, 25°03’S, 046°52’E, June (s. year) ( K [photo seen]) ; Service Forestier 11755, forêt sublittorale, sur sables, près du Vinany Be, au SW de Fort-Dauphin , 25°03’S, 046°56’E, fl., Feb. 1955 ( P, K, G, MO, WAG) .

Figures

FIG. 6. — Distributions of Talinella dauphinensis and segregate species: T. bosseri ($), T. dauphinensis (N), T. humbertii (▲), T. latifolia (★), T. tsitondroinensis (✚).