Olax lanceolata Cavaco & Keraudren, 1963

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 : 86-88

5. Olax lanceolata Cavaco & Keraudren

( Fig. 5 )

Bulletin de la Société botanique de France 110: 245 (1963) . — Type: Madagascar, Prov. Toliara, Tuléar, Besifaka , [22°38’S, 43°38’E], 11.II.1955, fl., Service Forestier 12814 (holo-, P-0048891!; iso-, P!, TEF).

ADDITIONAL MATERIAL EXAMINED. — Madagascar. Prov. Mahajanga, Bora, aux environs d’Ampombolava (Antsohihy), [15°01’S, 48°12’E], 16.III.1965, fl., SF (Capuron) 24071 (P!, TAN!, TEF!) . — Berivotra, sur le plateau de Berivotra, au Sud de Majunga , [15°54’S, 46°34’E], [100 m], 24.XI.1965, fr., SF (Capuron) 24294 (P!, TEF!) .

Prov. Toliara, Morondava, 20°17’S, 44°17’E, 1990, ster., Rahantamalala 200 (P!). — Kiranomena , 5 km au Sud de Kiranomena , [19°36’S, 45°37’E], 11.VIII.1954, ster., SF 51-R-243 (P!, TEF) . — Analamary, Tuléar [23°00’S, 44°33’E], 6.II.1951, fl. galls, SF (Rasolofoson) 2839 (P!, TEF!) . — Bekinana, Befasy, Morondava , [20°36’S, 44°27’E], [80-100 m], 15.IX.1954, fl. galls, imm. fr., SF (Valitera) 10869 (P[2]!, TEF!) . — Ambohimahavelona, Tuléar , [23°26’S, 43°54’E], 24.I.1955, fl., SF (Bototsalaoendry) 12677 (P!, TEF!) . — Antanimieva STF, station vers Ankaro, Morombe , [22°16’S, 43°46’E], 28.III.1955, imm. fr., SF (Verdet) 13314 (P!, TEF!) . — Tsivonoakely, au Nord du Fiherenana , [23°09’S, 43°37’E], [0-50 m], 30.XII.1961, fr., SF (Capuron) 20217 (P!, TEF!) . — Tanandava, près de Tanandava , [21°43’S, 43°45’E], 26.V.1965, fl. galls, imm. fr., SF (Capuron) 24117 (P!, TEF!) .

DESCRIPTION

Olax lanceolata has flowers with 3 (rarely 4) petals, 3 stamens, 6 staminodes, and a non-accrescent calyx in fruit. The species is distinguished from O. madagascariensis , the closest presumed relative, by its lanceolate or narrowly elliptic leaves with a length to width ratio of (3-)4-8:1 (vs. ovate or elliptic leaves with a l/w ratio of 2-3[-3.5]), leaf blades with a narrowly acute apex and cuneate base (vs. acuminate or rarely acute apex with a broadly rounded, obtuse, or rarely acute base), and by its smaller fruits (13-14 vs. 14-19 mm in diam.).

REMARKS

Since the type of Olax lanceolata was collected in 1955, Cavaco & Keraudren were unable to describe the species until after the publication of the Flore. The common occurrence of galled flowers and the rarity of fruiting collections have made this species somewhat difficult to define. It is interesting that relatively few collections have been made of a species so widely distributed in the western half of the island, with only one new collection made in the past 40 years.

DISTRIBUTION AND PHENOLOGY

Olax lanceolata occurs in dry and subarid forests located in western Madagascar from 0 to 600 m elevation (Fig. 11). The species has been recorded in flower in January through March and in the months of May and September. Fruiting takes place from November through December.

VERNACULAR NAME

Ambihotse (SF 51-R-243, 2839, 10869, 12677, 13314, 24117).

USE

Wood used to make boxes (SF 51-R-243).

CONSERVATION STATUS

Olax lanceolata has been collected in two protected areas (Antanimieva, Bora). The EOO for the species is 121 000 km2 and the AOO is 80 000 km2 (grid cell size 100 × 100 km). Given these figures, O. lanceolata is assigned a provisional conservation status of Least Concern (LC).

Figures

FIG. 5. — Olax lanceolata Cavaco & Keraudren: A, flowering branch; B, flower (one petal, one stamen, and one staminode removed); C, fruit. A, Service Forestier 13314; B, Service Forestier 12814 (type); C, Service Forestier 24294. Scale bars: A, 1 cm; B, 2 mm; C, 3 mm.