Olax madagascariensis (DC.) Valeton

Rogers, Zachary S., Malécot, Valéry & Sikes, Kendra G., 2006, A synoptic revision of Olax L. (Olacaceae) in Madagascar and the Comoro Islands, Adansonia (3) 28 (1), pp. 71-100: 88-90

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Olax madagascariensis (DC.) Valeton


6. Olax madagascariensis (DC.) Valeton  

( Fig. 6 View FIG )

Critisch Overzicht der Olacineae B. et H. 120 (1886). — Pseudaleia madagascariensis DC.   , Prodromus   1: 533 (1824). — Olax madagascariensis (DC.) Cavaco, Flore   de Madagascar 59: 4 (1955), nomen superfl. [isonym]. — Type: Madagascar, without precise locality, imm. fr., Du Petit-Thouars s. n. (holo-, P-00148708!; iso-, B-W 866!, P-00148707!).

Olax pseudaleia Willd. ex Steud.   , as “ pseudoleia   ”, Nomenclator Botanicus 1: 562 (1821), nom. nud.

Olax humbertii Cavaco & Keraudren   , Bulletin de la Société botanique de France 102: 119 (1955). — Type: Madagascar, Prov. Toliara, massif de l’Andohahela, vallée supérieure de la Sakamalio, [24°32’S, 46°41’E], 1100 m, I.1934, fl., fr., Humbert 13544 (holo-, P- 0048888!; iso-, P!); syn. nov.

ADDITIONAL MATERIAL EXAMINED. — Madagascar. Without precise locality, fl. galls, fr., Chapelier s. n. (P!).

Prov. Antsiranana, Nosy-Be, Réserve naturelle intégrale Lokobe , 13°25’10”S, 48°18’20”E, 40 m, 1.VIII.1994, fr., Antilahimena 146 (MO!, P!, TAN) GoogleMaps   . — Manongarivo RS, 14°04’S, 48°17’E, 200 m, 4.IX.1997, fr., Gautier et al. 3232 (G!, MO!, P!, TAN!). — Montagne d’Ambre PN, Grande Cascade , 12°31’36”S, 49°10’20”E, 840 m, 14.IV.1993, fl., fl. galls, Harder et al. 1567 (MO!, P!, TAN!) GoogleMaps   . — Ankarana RS, near Campement des Anglais , 12°54’S, 49°08’E, 150 m, 28.I.1994, fr., Leeuwenberg et al. 14334 (MO!, P!, WAG) GoogleMaps   . — Montagne d’Ambre PN, Grande Cascade, 12°29’S, 49°10’E, 580 m, 23.II.1992, fl., Malcomber et al. 1263 (G!, MO!, P!, TAN!). — Ankarana RS, 12°52’S, 49°14’E, 320 m, 23.XI.1989, fr., McPherson 14532 (MO!, P!, TAN!) GoogleMaps   . — Same locality, 12°51’S, 49°07’E, 150 m, 25.XI.1989, fr., McPherson 14544 (MO!, P!, TAN!, TEF) GoogleMaps   . — Antsahalalina, part of Bobankora Range , 12 km E of Daraina, 13°14’S, 49°46’E, 205-607 m, 10.II.1991, bud, Meyers & Boltz 268 (MO!, P!, TAN!) GoogleMaps   . — Ambondrobe, Fivondronana Vohémar, Firaisana Tsarabaria , Fokontany Manakana , 13°41’48”S, 50°05’18”E, 14.III.2004, imm. fr., Rabevohitra et al. 5182 (K!, MO!, P, TEF!). — Ankarana RS, aux environs d’Ambondromifehy , [12°53’S, 49°12’E], 6.X.1954, fr., SF (Capuron) 11262 (P!, TEF!) GoogleMaps   . — Montagne d’Ambre PN, bassin de la rivière des Makis, [12°30’S, 49°05’E], 750 m, 13.X.1954, fr., SF (Capuron) 11292 (P[2]!, TEF [2]!). — Ankarana RS, près de la grotte d’Ampandriampanihy , [12°57’S, 49°08’E], 13.XI.1958, fr., SF (Capuron) 18966 (P[2]!, TEF!) GoogleMaps   . — Same locality, 100 m, 13.XI.1958, fr., SF (Dansey) 19441 (P!, TEF!)   . — Ambinanifaho, à l’Ouest d’Isahana-Ambodipont, entre Antalaha et Sambava , [14°37’S, 50°07’E], 19.IV.1966, fl., fl. galls, SF (Capuron) 24640 (P[2]!, TAN!, TEF!) GoogleMaps   . — Ambanitazana, près d’Andrapengy, au N d’Antalaha , [14°40’S, 50°12’E], 22.X.1966, fr., SF (Capuron) 24965 (P!, TEF!) GoogleMaps   . — Sambava, au Sud de Sambava , [14°16’S, 50°10’E], 1-10.IV.1967, fl., fl. galls, SF (Capuron) 27707 (P!, TEF!) GoogleMaps   . — Diégo-Suarez , without precise locality, 17.X.1927, ster., Ursch 200 (P!)   .

Prov. Mahajanga, Andohajango, Beanamafaika [= Andohajango], Befandriana-Nord , [15°54’S, 48°30’E], 1.IV.1951, fl., SF (Rasolofo) 3344 (P[2]!, TAN!, TEF!) GoogleMaps   . — Ambondro-Ampasy, ouest de la presqu’île d’Antonibe ), [15°01’S, 47°16’E], [50 m], 2-5.V.1958, fl., SF (Capuron) 18559 (P[2]!, TEF) GoogleMaps   . — Ankobakobaka, Analarezy, Ankobakobaka , [15°08’S, 48°17’E], 29.VII.1970, ster., SF (Abraham) 30041 (P!, TEF!) GoogleMaps   .

Prov. Toamasina , Menaloha, forêt de la Menaloha, au bord de la route de Nickelville, [17°42’S, 48°28’E], 850 m, 23.XII.1944, fl., Cours (Herbier de la station agricole de l’Alaotra) 1985 [= Homolle 1985] (MO!, P[2]!, TAN!) GoogleMaps   . — Vohibola forest , Brickaville, 18°35’42”S, 49°14’02”E, 10.II.2003, fl., Rabevohitra et al. 4414 (G!, K!, MO!, P!, TEF) GoogleMaps   . — Mananara-Nord , réserve de Biosphère, forêt d’Ibanda , [16°09’S, 49°32’E], 5.II.1990, bud, Raharimalala 251 (P!). — Same locality, 12.II.1990, fl., Raharimalala 311 (P!). — Same locality, 18.II.1990, fl., Raharimalala 318 (P!). — Vohimenakely , Amparafaravola, Vohimena-Ambodisakoana, à 7 km de Vohimenakely, 17°20’05”S, 48°38’21”E, 850 m, 10.I.2002, fr., Ratovoson et al. 638 (MO!, TEF) GoogleMaps   . — Forêt de Vohibola , Brickaville, 18°34’12”S, 49°14’18”E, 16 m, 3.VIII.2003, imm. fl., Razakamalala & Rabehevitra 661 (MO[2]!, P!, TEF!) GoogleMaps   . — Ambila Lemaitso, 10 km E of Brickaville, 18°51’S, 49°08’E, 0-50 m, 4.IV.1987, fl., Schatz & Lowry 1312 (MO!, P!). — Maroantsetra GoogleMaps   , 5-12 km SW of Maroantsetra along Route Nationale 5, 15°30’S, 49°39’E, 10 m, 28.XI.1987, fr., Schatz et al. 1797 (MO!, P!, TAN!, US!). — Tampolo STF, au Nord de Fénérive, [17°17’S, 49°23’E], XI.1953, fl., SF (Capuron) 8638 (P[2]!, TEF!) GoogleMaps   . — Same locality, 6.III.1954, fl., SF 9601 (P[2]!, TEF!)   . — Same locality, 25.VIII.1955, fl. galls, SF (Zavah) 15125 (P!, TEF!)   . — Same locality, 26.IX.1956, imm. fr., SF 16099 (P!, TEF!)   . — Antoraka , environs de la Baie d’Antongil, à Antoraka, [15°29’S, 49°39’50”E], [0-100 m], 14.IX.1957, fr., SF (Capuron) 18275 (P[3]!, TEF!) GoogleMaps   . — Ambila Lemaitso STF, [18°49’S, 49°08’E], [30 m], 26.X.1963, imm. fr., SF (Capuron) 22745 (P!, TEF!) GoogleMaps   . — Varingotra , à l’Ouest de Maroantsetra, [15°28’S, 49°40’E], 5.XI.1963, fl., SF (Capuron) 22873 (P!, TAN!, TEF!) GoogleMaps   . — Same locality, bud, SF (Capuron) 22875bis ( TAN!)   . — Andilamena , village le plus proche Ampatakana, [17°01’S, 48°35’E], 14.XI.1966, fr., SF 26230 (P!). — Tampina, partie méridionale de la forêt de Vohibola, [18°31’S, 49°17’E], 17.XII.1967, ster., SF (Capuron) 28060bis (P!, TEF!) GoogleMaps   . — Andranokoditra , Akanin’ny Nofy , Ambila, Brickaville, 18°36’S, 49°15’E, 15.XII.1982, fl., SF (Rabevohitra) 32483 ( TEF!) GoogleMaps   . — Masoala Peninsula , Point Tompolo, [15°39’30”S, 49°57’30”E], 0 m, VII.1993, fr., Zjhra & Hutcheon 419 (MO!, P!, TAN) GoogleMaps   .

Prov. Toliara, Zombitse National Park , near Sakaraha, 1 km N of National Route #7, 22°53’11”S, 44°41’32”E, 800 m, 13.I.2006, ster., Rogers et al. 840 (MO!, P!, TAN!) GoogleMaps   . — Miandrivazo, située au sud de Miandrivazo route Belo, Ampemasana, [19°31’S, 45°28’E], 0-100 m, 24.V.1957, fr., SF (Ralaiarison) 16987 (P!, TEF!) GoogleMaps   . — Zombitse, forêt de Zombitsy, à l’E de Sakaraha, [22°49’S, 44°40’E], 700-800 m, 20.VI.1958, ster., SF (Capuron) 18597 (P!, TEF!) GoogleMaps   . — Analavelona, bassin de la Mananadabo dans le Massif de l’Analavelona , au Nord du Fiherenana, [22°30’S, 44°03’E], 1000-1300 m, 13-15.XII.1962, fl., fr., SF (Capuron) 22175 (P[2]!, TAN!, TEF!) GoogleMaps   .


Olax madagascariensis   has flowers with 3 (rarely 4) petals and stamens, 6 (rarely 5 or 7) staminodes, and a non-accrescent calyx in fruit. This species is distinguished from O. capuronii   by its larger, differently shaped leaves (4.5-11.5 cm long and ovate, rarely elliptic or obovate, vs. 1-4.2 cm long, obovate, rarely elliptic or ovate), acuminate or rarely acute apex (vs. broadly rounded, obtuse, or rarely acute or emarginate), more conspicuous venation, and by the spheroid fruit (vs. obovoid).


Pseudaleia (Du Petit-Thouars 1806)   , based on type material collected by Du Petit-Thouars himself, was originally published without a species epithet and was illegitimate because Olax   L. was mentioned in synonymy. Steudel (1821) cited the name Olax pseudoleia   , which is invalid as it lacks a description. Even if we interpret the mention of “Pet. Th. Willd. Herb.” in Steudel to be an indirect reference to the validly published Pseudaleia Thouars   , the name cannot be considered valid since the genus was not recognized as monospecific, therefore part (c) of Art. 41.3 of the Code ( Greuter et al. 2000) does not apply. De Candolle (1824) later validated the generic and specific names simultaneously with the description of Pseudaleia madagascariensis   , citing Du Petit-Thouars’ work and republishing his original description, almost word-for-word.

Cavaco & Keraudren (1955a) superfluously transferred Pseudaleia madagascariensis   into Olax   as they were unaware of Valeton’s (1886) earlier valid combination. In a separate paper, Cavaco & Keraudren (1955c) described O. humbertii   . Their belief that O. humbertii   represented a species distinct from O. madagascariensis   appeared reasonable due to the variation in populations caused by different moisture regimes, combined with a lack of adequate fruiting material.


Olax madagascariensis   occurs in humid littoral forest, subhumid inland forest, and dry subarid forest from 0 to 1100 m elevation (Fig. 9). The majority of populations grow in the northern third of the island, but a few disjunct populations are found much further south in the Toliara province at Analavelona, Andohahela , and Zombitse. Olax madagascariensis   has been recorded on several different substrate types (e.g., sand, laterite, calcareous limestone, granite). The species flowers and fruits from August through May   .


Ambavy (SF 9601); Fanavé (Chapelier s. n.); Kimbimbala (Malcomber et al. 1263); Kirandrambaiavy (SF 18559); Maitsokely (Meyers & Boltz 268; SF 32483); Maitsoririnina (Rabevohitra et al. 5182; SF 8638, 15125, 16099); Manarimbitana (Meyers & Boltz 268; SF 32483); Manary Toloho (SF 16987); Remaitso (SF 11292);Tsihanimboana (Rakotonandrasana et al. 679).


Wood used for construction material (SF 16099, 16987, 26230).


Olax madagascariensis   is known from 10 protected areas (Ambila Lemaitso, Andohahela, Ankarana, Lokobe, Mananara-Nord, Manongarivo, Masoala, Montagne d’Ambre,Tampolo, Zombitse). The species has an EOO of 390 000 km2 and an AOO of 160 000 km2 (grid cell size 100 × 100 km). These figures indicate that the species should be considered a species of Least Concern (LC).


In the Flore, Cavaco & Keraudren (1955a) cited the type of Pseudaleia madagascariensis   as “Madagas- car, sans indication: Du Petit-Thouars s. n. (type)”. Two P specimens bear typewritten “Herbier du Petit-Thouars” labels and closely match the description of P. madagascariensis   . One of those sheets, P-00148708, with a single immature fruit loose in the fruit envelope, was first annotated as “ O. madagascariensis   ” by Cavaco in 1954 and sometime later by an anonymous worker as the type of “ O. pseudaleia Steud.   ”. The second annotation presumably belongs to Capuron, who recognized the species under the invalid Steudel name in his report ( Capuron 1968). The other P sheet, P-00148707, is sterile and was annotated by Cavaco in 1955 as “ O. madagascariensis   ”.

In the Willdenow herbarium, two sheets filed under Pseudaleia   (B-W 866) and Pseudaleioides   (B-W 865) have been mislabelled. Sheet B-W 866 taxonomically belongs to Pseudaleia madagascariensis DC.   (= Olax madagascariensis (DC.) Valeton   ) but bears the annotation “ Ol. Pseudalejoides ”, while B- W 865 corresponds to Pseudaleioides thouarsii DC.   (= O. thouarsii (DC.) Valeton   , species no. 8) but was incorrectly annotated as “ Ol. Pseudaleja ”. Sheet P-00148708 should be regarded as the holotype of Pseudaleia madagascariensis   . Sheets P-00148707 and B-W 866 can be considered isotypes.


Parc de Tsimbazaza


Missouri Botanical Garden


Wageningen University


Centre National de la Recherche Appliquée au Developement Rural














Olax madagascariensis (DC.) Valeton

Rogers, Zachary S., Malécot, Valéry & Sikes, Kendra G. 2006

Olax pseudaleia Willd. ex

Nomenclator Botanicus 1821: 562