Olax pseudaleioides subsp. sabulicola Madagascar Olax antsiranensis O. thouarsii A synoptic revision of Olax L. (Olacaceae) in Madagascar and the Comoro Islands Rogers, Zachary S. Malécot, Valéry Sikes, Kendra G. Adansonia 2006 3 28 1 71 100 492KB Rogers & Malécot & Sikes, 2006 Rogers & Malécot & Sikes 2006 [294,494,1261,1287] Magnoliopsida Olacaceae Olax Plantae Santalales 4 75 Tracheophyta species antsiranensis sp. nov.  Z.S.Rogers, Malécot & Sikes, sp. nov.( Fig. 1)   “  Olax pseudaleioidessubsp. sabulicola” Capuron, Olacacées, Opiliacées et Santalacées arbustives ou arborescentes de   Madagascar: 13 (1968), nomen inval. [ineffective publication].  Olax antsiranensis a O. thouarsii in laminis 1.5-4 (haud 5-12) cm longis (n.b.: bracteis interdum foliaceis!) plus minusve concoloribus et apicibus emarginatis (haud paginis abaxialibus glaucis et apicibus acutis acuminatis vel raro obtusis vel rotundatis), et ligulis petalorum 0-0.3 (haud 0.6-1) mm longis indumento pubescenti sparso (haud dense) praeditis, differt.   TYPUS. —  Madagascar.Prov. Antsiranana, au Sud du Mont Raynaud, sur sables, [ 12°30’S, 49°27’E],  26.IV.1963, fl., Service Forestier (Capuron) 22719(holo-, P!; iso-, P- 00418010!, TEF!).   PARATYPES. —  Madagascar. Prov. Antsiranana, souspréfecture de Vohémar, commune rurale de Daraina, forêt de Bekaraoka, partie sud Andranostimaty, 13°11’S, 49°42’E,  130 m,  10.III.2003, fl., Gautier et al. 4305(G, INH!). —  Ramena, Andavakoera, à 8 kmau Suddu village Andavakoera, forêt sèche sur sable, 12°20’53”S, 49°21’27”E,  50 m,  11.VIII.2004, imm. fr., Guittou et al. 75(K!, MO!). —  Analabe forest, Fivondronana Vohémar, Fokontany Anjiabe, 13°04’14”S, 49°53’40”E,  26.II.2003, fl.,  Rabevohitraet al. 4554(K!, MO!, P!, TEF). — Fivondronana Diego II, Commune Ramena, Fokontany Andavakoera, forêt sèche d’Andranonankomba, Montagne des Français, 12°20’48”S, 49°21’28”E,  88 m,  7.IX.2004, fr., Randrianaivo et al. 1074(G!, MO!, P, TAN, TEF). — Same locality, 12°23’02”S, 49°20’12”E,  310 m,  28.III.2004, fl., Ratovoson et al. 735(MO!, P, TAN). —  Tendrombohitr’Antsingy[= Montagne des Français], [ 12°22’S, 49°21’E],  26.XI.1958, fr., SF (Capuron) 20103(P!, TEF!). —  SakaramySTF, forêt d’Analandriana, près de Sakoramy( Diégo-Suarez), [ 12°26’S, 49°16’E],  17.XII.1963, fr., SF (Capuron) 23017(P!, TEF!). —  Ambongoabomassif, à l’Ouest de Diégo-Suarez, [ 12°15’S, 49°10’E],  26.I.1966, fr., SF (Capuron) 24442(P!, TEF!). —  Vohémar, [ 13°22’S, 50°00’E],  14.X.1966, fr., SF (Capuron) 24867(P!, TEF!). DESCRIPTION Trees to 10 mtall. Branches glabrous; young branches 4-sided, winged; older branches terete, darker; bark cracked, exfoliating. Leaves alternate, distichous, elliptic or ovate, rarely obovate, 1.5- 4 cmlong, 9-23 mmwide, c. 2-2.5 times longer than wide; leaf blades chartaceous, glabrous, surfaces smooth, rarely slightly wrinkled, usually darker in color adaxially, base acute-cuneate (decurrent with petiole), margin slightly revolute, more obvious in lower half, apex apparently emarginate, sometimes with a short mucron in the sinus; midrib depressed or slightly raised adaxially, raised abaxially, glabrous; venation usually conspicuous on both surfaces, less pronounced abaxially, secondary veins c. 5 pairs per side; petioles 0-0.5 mmlong, c. 1 mmin diam., glabrous. Inflorescences racemose or pseudosolitary; axes 4-sided, c. 0.5 mmin diam., reaching 7 mmlong, proliferating with up to 5 flowers; floral pedicel 2.2-2.8 mmlong, c. 0.5 mmin diam. Flowers hermaphroditic, tubular, heterostylous; calyx cupuliform, green, 1-1.2 mmlong, semimembranous, glabrous, margin truncate; petals 5, white, oblong, 5.8-7.7 mmlong, glabrous adaxially; petal lobes c. 3 mmlong, 1.1-1.7 mmwide; petal ligule absent or up to 0.3 mmlong, sparsely puberulent or glabrous; free portion of filaments 1-2 mmlong; fertile stamens (5) 6 (7); anthers oblong, c. 1.5 × 0.7 mm, longitudinally dehiscent; staminodes 4 or 5, each bifid portion narrowly elliptic, c. 2 × 0.5 mm, membranous, glabrous, base thick, dark, articulate with filament; nectary disc annular, 0.1-0.2(-0.3) mm tall, glabrous; ovary ovoid-spheroid, c. 1.2 × 1 mm; style c. 0.4 mmin diam., articulate above ovary in immature fruit; long style not seen; short style 2.3-2.7 mmlong; stigma capitate, 3-lobed, 0.4- 0.6 mmin diam., papillate. Drupes transversely ellipsoid, uniformly depressed at both poles, 1.1-1.2 cmlong, 1.5-1.7 cmin diam., yellow, glabrous; accrescent calyx surrounding base of fruit, thin and chartaceous, 7-8 mmin diam., margin tearing irregularly into 4-8 lobes; stylar remnants c. 0.2 mmlong.  REMARKS The flowers of  Olax antsiranensishave 5 petals, (5) 6 (7) stamens, 4 or 5 staminodes, and a weakly accrescent calyx in fruit.  Olax antsiranensisis distinguished from  O. thouarsiiby its 1.5-4 (vs. 5- 12) cm long leaves, the more or less concolorous leaf blade with an emarginate apex (vs. abaxially glaucous blade with an acute, acuminate, or rarely obtuse or rounded apex), and by the 0-0.3 (vs. 0.6-1) mm long, sparsely (vs. densely) pubescent petal ligule. Please note that leaves of  O. thouarsiishould not be confused with its foliose bracts (see species no. 8 for further discussion). The placement of this taxon was not addressed in the Flore( Cavaco & Keraudren 1955a) because no collections were available at that time. Capuron (1968)collected  Olax antsiranensison five occasions, considering it to be a subspecies of  O. thouarsii(though he regarded  O. pseudaleioidesto be the correct name for the species). We believe that  O. antsiranensisdeserves recognition at the rank of species.  DISTRIBUTION AND PHENOLOGY   Olax antsiranensisoccurs in a few dry forest fragments in northern Madagascarnear Diégo-Suarez and Vohémar from 0 to 310 melevation (Fig. 11). The species grows on sand, calcareous limestone, and lateritic soil on basaltic rock. It flowers February through April and fruits from August to January.  VERNACULAR NAME Kombimba ( Ratovoson et al. 735); Sarinkombimba ( Guittou et al. 75).  FIG. 1. —  Olax antsiranensisZ.S.Rogers, Malécot & Sikes: A, flowering branch; B, flower (two petals, two stamens and two staminodes removed); C, fruit. A, Service Forestier 22719(type); B, Rabevohitra 4554; C, Service Forestier 20103. Scale bars: A, 1 cm; B, 3 mm; C, 4 mm. USE “Fakaboka” ( Ratovoson et al. 735). In Malagasy, Fakaboka means the plant is used by sorcerers to curse people (F. Ratovoson pers. comm.). CONSERVATION STATUS   Olax antsiranensisgrows in one protected area (Sakaramy). The EOO of the species is 1400 km 2, a figure which easily meets the requirements of B 1 inthe EN category (i.e. EOO < 5000 km2). AOO for the species is 600 km 2(grid cell size 10 × 10 km) and does not quite qualify as EN in the B2 category (i.e. AOO < 500 km2). Therefore, the spe- cies is assigned a provisional conservation status of Vulnerable (VU B1ab + 2ab). 1963-04-26 TEF Sud du Mont Raynaud Madagascar -12.5 Antsiranana 1293 49.45 4 75 1 Antsiranana 2003-03-10 INH de Vohemar & de Daraina & de Bekaraoka Madagascar 130 -13.183333 Andranostimaty 1291 49.7 Prov. 4 75 1 Antsiranana paratype 2004-08-11 MO Madagascar Ramena 50 -12.348055 Sud 21 49.3575 Andavakoera 4 75 1 paratype 2003-02-26 2004-09-07 2003-02-26 MO, TEF, TAN Fivondronana Diego II & Commune Ramena & Fokontany Andavakoera & d'Andranonankomba Madagascar Analabe forest 88 5 76 -12.383889 Fokontany Anjiabe 21 49.336666 Fivondronana Vohemar 4 75 1 paratype 1958-11-26 TEF Madagascar -12.366667 Tendrombohitr'Antsingy 1293 49.35 5 76 1 paratype 1963-12-17 TEF de Sakoramy Madagascar Sakaramy -12.433333 Diego-Suarez 1293 49.266666 d'Analandriana 5 76 1 paratype 1966-01-26 TEF Madagascar -12.25 l'Ouest de Diego-Suarez 1293 49.166668 Ambongoabo 5 76 1 paratype 1966-10-14 TEF Madagascar -13.366667 Vohemar 1291 50.0 5 76 1 paratype