Talinella latifolia Appleq., 2005

Applequist, Wendy L., 2005, A revision of the Malagasy endemic Talinella (Portulacaceae), Adansonia (3) 27 (1), pp. 47-80 : 70-72

8. Talinella latifolia Appleq. , sp. nov.

Haec species Talinellae tsitondroinensis Appleq. affinis, sed ab ea foliis late ellipticis (2.3-) 3.5-6.5 cm longis glandulari-maculatis apices plerumque mucronulatis, squamis gemmae foliaris saepe curvatis apicis pallidis, floribus maturiscentibus plerumque terminalibus, bracteis late deltoideis vel absentibus, pedicellis 5-9 mm longis, sepalis 2.5-3.0 mm longis, petalis 4 vel 5 roseis 3.0- 4.5(-5.5) mm longis atque stigmatibus 1.4-1.6 mm longis plus minusve papillosis stylo brevi insidentibus distinguitur.

TYPUS. — Perrier de la Bâthie 12533, Bassin de la Mania, granite, rocailles, 700 m, fl., Mar. 1919 (holo-, P!).

Shrub. Twigs straight to slightly crooked, light brown, sometimes with small pale circular lenticels; the smallest twigs papillose with white and brown papillae. Leaves broadly elliptical to suborbicular, (2.2-) 3.5-6.5 cm long, (1.0-)2.0- 3.5(-4.3) cm broad, often somewhat asymmetrical; apex usually mucronulate to apiculate, rarely acute or rounded or emarginate and sometimes with mucron; base tapering; texture crassulescent in vivo, papery when dry; surface dark-spotted and somewhat translucent; midrib conspicuous, higher order venation visible beneath. Probably dioecious. Inflorescences terminal or lateral, open, the fertile portion 2.0- 4.5 cm long; peduncle and rachis slender, white-papillate; bud scales below inflorescences 0.4-0.9 mm long, sometimes inward-curving or recurved and with pale apex; bracts 0.3-0.8 mm long, sometimes absent or reduced to small ridge, broadly triangular with the base prominently curved in a semicircle around the rachis, apical portion or whole bract somewhat darkened. Pedicel 5-9 mm long. Sepals 2.3-3.0 mm long, broadly oblong, apex rounded to apiculate. Petals 4-5, 3.0-4.5(-5.5) mm long, pink or white, frequently unequal, often narrowly oblong, sometimes with an acute apex. Filaments c. 2.5-3.0 mm long, flattened and slightly ciliate below; anthers c. 0.5 mm long; staminodes of female flowers bearing occasional anthers 0.2- 0.5 mm long. Stigma branches 2-3, 1.4-1.6 mm long, somewhat flattened at apex, sometimes irregularly short-ciliate and developing a warty appearance; style <0.5 mm long; ovary round. Immature fruit globose, to 5 mm in diameter, with remnants of perianth and staminodes persisting; mature fruit not known. — Fig. 9 .

The type of T. latifolia was placed by EGGLI (1997) within the southeastern T. dauphinensis , which differs in having leaves without dark spots, visible secondary venation, or mucronulate apices; smaller and unequal sepals; and petals that are whitish rather than pink. Talinella latifolia also closely resembles the northern species T. pachypoda , with which it may share unusual pink corollas, and T. tsitondroinensis , but may be distinguished from these by leaf morphology. The leaves of T. pachypoda are usually symmetrical and slightly narrower than those of T. latifolia ; the margins are often minutely papillate, the upper surface is not dark-spotted, and the apex is less variable, frequently apiculate but not mucronulate. The petals of T. pachypoda are <3.5 mm long, and the bracts are sometimes> 1 mm long and narrowly triangular; the immature fruit has an apical beak, and the mature fruit may dehisce apically. Talinella tsitondroinensis has narrower leaves than T. latifolia , usually with rounded apices; narrower bracts (which in both species are sometimes reduced to scales or ridges); and larger stigma branches (up to 3 mm, sometimes branching). Petal number varies within a single individual in both species (4-5 in T. latifolia and (2-) 5 in T. tsitondroinensis ). These two species are otherwise quite similar. The holotype of T. latifolia has small anthers on a few staminodes, but is probably functionally female; related species ( T. pachypoda , T. dauphinensis ) are apparently dioecious.

DISTRIBUTION. — Talinella latifolia is known from three collections in two widely separated areas ( Fig. 6 ). The type was collected in central Madagascar, near the Mania River on granite at about 700 m. If the label data are accurate, the location of the collection would be limited to the portion of the Mania east of the juncture with the Ankotrofotsy or Tsiribihina River, but west of about 046°30’E, as the elevation of the river basin farther east exceeds 700 m. RAZAFIMAN- DIMBISON & ANDRIANANTOANINA collected material of both T. pachypoda and T. latifolia under the same number at Ankarana, indicating that these species sometimes share similar habitats and that the potential habitat of T. latifolia may be rather diverse, since this collection was probably on limestone rather than granite. A photograph of another specimen from the extreme north (Ramananjanahary et al. 9) also appears to represent T. latifolia ; the petals are reported to be white rather than pink.

CONSERVATION STATUS. — Provisional IUCN Red List Category: Vulnerable (VU D2). As only three collections of T. latifolia have been seen, population data are inadequate to draw firm conclusions. The original range may have been large, given the considerable distance between the Mania River and the northern habitat, but much of the original vegetation between these locations h a s b e e n d e s t roye d. Re m a i n i n g ve g e t a t i o n patches around central population centers have long been accessible to collectors, so the absence of other collections suggests that the species may be sparsely distributed. Talinella latifolia also seems to be a rare plant within its northern range: RATOVOSON (pers. comm.) reports seeing only two individuals in 11 days of collection near Montagne des Français.

PARATYPES. — MADAGASCAR: Prov. Antsiranana: Ramananjanahary et al. 9, Ampitiliantsambo, sur rochers, 12°23’01”S, 049°23’09”E, 289 m, fl, 13 June 2004 ( TAN [photo seen]); Razafimandimbison & Andrianantoanina 97b, District d’Ambilobe, Canton de Mahamasina , N de Mahamasina , Réserve Spéciale d’Ankarana , route de la Grotte des chauves-souris, 12°58’S, 049°08’E, 50 m, fl., 15 June 1995 ( MO) .

Figures

FIG. 9. — Talinella latifolia Appleq.: A, habit; B, diagram of entire inflorescence; C, female flower; D, leaf (abaxial surface); E, leaf (adaxial surface). Perrier de la Bâthie 12533.

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