Talinella tsitondroinensis Appleq., 2005

Applequist, Wendy L., 2005, A revision of the Malagasy endemic Talinella (Portulacaceae), Adansonia (3) 27 (1), pp. 47-80 : 75-76

11. Talinella tsitondroinensis Appleq. , sp. nov.

Haec species Talinellae pachypodae Eggli affinis, sed ab ea habitu minore laxiore sine caudice, foliorum apicibus saepe asymmetricis rotundatis vel breviter acuminatis vel leviter emarginatis, squamis gemmae foliaris acuminatis apicibus fuscatis, inflorescentiis breviter paniculiformibus, bracteis 0.4-0.6(-1.2) mm longis vel sursum ad squamas reductis, floribus maturis lateralibus vel terminalibus, pedicellis 3-7 mm longis, sepalis late ovatis aequalibus, petalis (2 ad) 5 albidis (3.0-)3.6-4.0 mm longis, florum femineorum staminodiis usque ad 4 mm longis roseis interdum antheras gerentiis ac stigmatibus 2 vel 3 usque ad 3 mm longis interdum semel ramosis atque fructu globoso semen solitarium usque ad 3 mm longum continente distinguitur.

TYPUS. — Perrier de la Bâthie 1385, Prov. Mahajanga, rochers basaltiques [de la cime du] Mt Tsitondroina , 16°44’S, 046°24’E, fl., fr., Jan. 1900 (holo-, P!; iso-, P!) .

Shrub to 0.5 m with lax, possibly sarmentose branches. Twigs straight, reddish brown; lenticels on large twigs pale, large and elliptical to small and round; smallest twigs usually papillose with brown and white papillae. Leaves elliptical to oblong, ovate or obovate, (1.5-)2.5-5.0 cm long, (0.9-)1.2-1.8(-2.0) cm broad, sometimes somewhat asymmetrical; apex rounded to roundedacute, occasionally short-apiculate or shallowly emarginate; base tapering, usually somewhat concave; margins frequently slightly revolute, sometimes barely papillose; blade crassulescent, rather thin when dried; midrib conspicuous at least on lower surface, higher-order venation observable beneath. Inflorescences short-paniculiform, borne on short or long lateral twigs, <3 cm long with few fertile flowers; peduncle and rachis slender, glabrous or white-papillate; bud scales below inflorescence (0.6-)0.8-1.0 mm long, dark, acuminate, the base of the lower ones sometimes mottled and papillose like the twig; bracts c. 0.4-0.6(-1.2) mm long or reduced to scales distally, narrowly triangular, usually with inconspicuous darker tip or streak down the midline. Pedicel 3-7 mm long. Sepals 2. 0-2.6 mm long, broadly ovate; apex rounded or obtuse. Petals (2-)5, (3.0-)3.6-4.0 mm long, white, oblong to narrowly obovate; fused petals sometimes suborbicular, convex. Staminodes of female flowers filiform, with lower portion ciliate, to 4 mm long, rose, with occasional anthers 0.4- 0.9 mm long. Stigma branches 2-3, sometimes once-branched, rose, to 3 mm long at maturity, sessile, flattened, ragged-edged. Immature fruit globose, up to 5.8 mm in diameter; perianth and staminode remains frequently persistent; seeds 1 per fruit, broadly elliptical to suborbicular, to 3 mm long, with a shallow ridge around edge. — Fig. 11 .

The single known collection of Talinella tsitondroinensis is from northwestern Madagascar, well outside the known range of any other member of the genus. It is a delicate shrub with few-flowered inflorescences and twigs bearing brown and white papillae, and thus belongs to the group of species including T. dauphinensis and T. pachypoda ; the type was included within EGGLI’ s (1997) concept of T. dauphinensis , but is probably more closely related to T. pachypoda , to which it has the closest geographic proximity, or to T. latifolia , which it most closely resembles (see discussion under that species). It is distinguished from T. dauphinensis by its narrower leaves with visible secondary venation and frequently rounded apices; slightly larger (2. 0-2.6 mm vs 1. 0-2.3 mm) and equal sepals; stamens> 2.5 mm long and probably c. 20 in number; and stigmas that are> 2 mm long, pink and flattened (rather than whitish and terete). It is distinguished from T. pachypoda by its leaf shape (which, though variable, usually is not symmetrically apiculate as is common in T. pachypoda ); larger, white petals; long pink stigmas; and globose, unbeaked fruits. The size and number of the seeds of T. tsitondroinensis (up to 3 mm long, and only 1 per fruit in the type specimen) may also prove diagnostic. Like T. latifolia , T. tsitondroinensis has occasional anthers in female flowers, but is likely to be functionally dioecious.

DISTRIBUTION. — Talinella tsitondroinensis is known only from Mt Tsitondroina , in northwestern Madagascar ( Fig. 6 ), on basalt. One of the duplicates indicates that the type collection was from the summit; one summit of Tsitondroina is c. 391 m.

CONSERVATION STATUS. — Provisional IUCN Red List Category: Data Deficient ( DD). As T. tsitondroinensis is known only from the type collection, and no efforts have been made to relocate it, it is considered to be Data Deficient. However, it may well prove to be endangered. The single known locality is not protected .

Figures

FIG. 11. — Talinella tsitondroinensis Appleq.: A, habit; B, female flower; C, leaf, adaxial surface; D, leaf, abaxial surface. Perrier de la Bâthie 1385.

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