Talinella xerophila Appleq., 2005

Applequist, Wendy L., 2005, A revision of the Malagasy endemic Talinella (Portulacaceae), Adansonia (3) 27 (1), pp. 47-80 : 76-78

12. Talinella xerophila Appleq. , sp. nov.

Haec species Talinellae microphyllae Eggli similis, sed ab ea ramunculis papillosis papillis albis et brunneis, foliis late ovatis usque ad 6 mm longis et 3 mm latis marginibus non revolutis, bracteis paucis pallidis plerumque minus quam 0.5 mm longis, pedicellis 4-6 mm longis insuper dilatatis atque petalis 3 ad 5 saepe inaequalibus et irregulariter connatis post maturitatem fructus persistentibus differt.

B mm 0 2A C D

mm 2 mm 3 mm 2

TYPUS. — Service Forestier 28983, Prov. Toliara, environs de Sihanamavo, au S d’Ampanihy, sur sables roux, 24°50’S, 044°43’E, fl., fr., 10 Dec. 1969 (holo-, P!; iso-, P!, TEF!) .

Shrub, 0.5-1.0(-2.5) m high. Twigs frequently contorted; bark on larger twigs wrinkled, cracked or peeling, gray-brown to dull brown, glabrous; lenticels absent to numerous; small twigs densely papillose with white and brown papillae or rarely glabrous; leaves and inflorescences clustered on very short shoots or borne singly on small slender lateral twigs. Leaves broadly obovate, to 6 mm long and 3 mm broad, thick or succulent; apex rounded, usually minutely apiculate; midrib usually visible but not prominent beneath. Inflorescences small cymes, borne in leaf axils or terminal on short shoots, reduced to 1-2 flowers or up to 3 times branched with several buds; peduncle filiform, white-papillate; bracts and bud scales very few, pale, 0.2-0.5(-0.8) mm long. Probably dioecious. Pedicel 4-6 mm long, sparsely papillate to glabrate. Sepals 1.2-1.8(-2.0) mm long, thicktextured, somewhat warty. Petals 3-5, irregularly fused, sometimes partly connate, often unequal or with one borne inside another, (1.5-)2. 0- 3.5 mm long, pink to pinkish green, greenish or white. Filaments c. 1.5 mm long, filiform; anthers 0.5 mm long, oblong. Female flowers sometimes with short, ciliate-edged staminodes. Stigma branches (2-)3, 1.1-1.6 mm long, slightly flattened, somewhat papillose or irregular along one edge, sessile. Fruit bacciform, elliptical to globose, reddish, 3.5-5.0 mm high, thin-fleshed, often with remnants of calyx and staminodes persisting, occasionally sparsely papillose; seeds 2-6, broadly reniform or elliptical, 1.7-2.2 mm long, with or without shallow obtuse ridge. Remains of perianth sometimes persist after fruit has fallen. — Fig. 12.

The material here classified as Talinella xerophila was included in EGGLI’ S (1997) concept of T. microphylla . Both species are adapted to dry depauperate southern habitats, and they bear an extraordinary superficial resemblance. However, T. xerophila typically has 3-5 petals rather than 2, its stigmas are sessile, and its twigs are often densely pubescent with white and brown papillae; it may be dioecious rather than gynodioecious, although existing material is limited. These characters suggest that T. xerophila is more closely related to the widespread group of species including the southeastern T. dauphinensis and T. humb e r t i i t h a n t o T. m i c ro p h y l l a a n d T. g re ve i. Talinella xerophila may be further distinguished by its leaves, which are broadly obovate (to 6 mm by 3 mm) and usually not strongly rolled up as in T. microphylla , and by its tiny inflorescences with fewer, paler bracts. The petals may be pink to green or white in T. xerophila , but are never reported to be pink in T. microphylla . Dry portions of the perianth sometimes linger on the pedicel after the sexual parts have been lost and the fruit perhaps dispersed, a state that has not been observed in any other species of Talinella . Talinella xerophila has a much wider distribution than T. microphylla and is found on sand, whereas T. microphylla occurs on limestone around Lac Tsimanampetsotsa.

DISTRIBUTION. — Talinella xerophila is known from the arid region at the southern tip of Madagascar ( Fig. 10 ); it grows primarily on sand at low altitudes.

VERNACULAR NAME. — Sohy (Bosser 4101).

CONSERVATION STATUS. — Provisional IUCN Red List Category: Least Concern (LC). It should be noted that, although the distribution of T. xerophila is broad, only seven localities are known, and the habitat is not protected.

PARATYPES. — MADAGASCAR: Bosser 3752, Prov. Toliara, Ifotaka , bush sur sables roux, 24°48’S, 046°08’E, fl., Nov. 1952 ( P) ; Bosser 4101, Prov. Toliara, Ifotaka ( Mandrare ), bush xérophile sur sable, 24°48’S, 046°08’E, fl., fr., Nov. 1952 ( P, MO, K, TAN) ; Bosser 14436, Prov. Toliara, environs d’Ambovombe (sud), bush dégradé, 25°10 ’S, 046°05’E, Mar. 1960 ( P, MO) ; Chauvet 414, Prov. Toliara, route de Tsihombe à Beloha , 3 Apr. 1953 ( P, TEF) ; Peltier 5871, Prov. Toliara, Tranoroa , 24°42’S, 045°04’E, fl., 2 Apr. 1966 ( P) ; Randrianaivo et al. 884, Fiv. Fort-Dauphin , Com. Ranopiso, Fkt. Andranomainty, Forêt de Mangatsiaka à 52 km W de Fort-Dauphin , RN 13, forêt sèche à Alluaudia , 24°58’33”S, 046°32’46”E, 90 m, fr., 3 Dec. 2002 ( MO) ; Service Forestier 22463, Antanimora , près du terrain d’aviation, bush dégradé sur sables, 24°49’S, 045°40’E, 26 Jan 1963 ( TEF) .

UNCLASSIFIABLE SPECIMENS

MADAGASCAR: Bosser 17406, Prov. Fianarantsoa, district Ihosy, route de Ranotsara, vestige de forêt tropophile, fl., Feb. 1963 ( P) . — Bosser 17900, Prov. Fianarantsoa, environs d’Ihosy, fr., Feb. 1968 ( P) .

These specimens from the central part of southern Madagascar fall into the group of species affiliated with T. dauphinensis . Bosser 17406 was collected at the same locality as Bosser 17406bis (the type of T. bosseri ; cf. Fig. 4 ) but has leaves of a very different shape (broader, shorter, and more symmetrical), smaller inflorescences, and smaller flowers. It was suggested by EGGLI (1997) to represent a disjunct locality of T. pachypoda , otherwise known only from the extreme north, but this identification is inconsistent with floral morphology. A fruiting specimen from the nearby Ihosy region, Bosser 17900, has similar broad, papery leaves and small infructescences. These two specimens appear different from the large-leaved southern specimens (especially Hu m b e r t 1 3 1 1 5) t e n t a t i ve l y p l a c e d w i t h i n T. humbertii , and cannot be identified with any other species herein recognized. Both are in poor condition, with little fertile material and most of the leaves broken or suffering from precollection insect damage, so that an adequate description could not be produced. As the habitat around Ihosy is greatly degraded, these populations, if still present, may be in imminent danger of extinction and their relocation would be highly desirable.

Figures

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

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