Canarium arcuatum Daly, Raharim. & Federman, 2015

Daly, Douglas C., Raharimampionona, Jeannie & Federman, Sarah, 2015, A revision of Canarium L. (Burseraceae) in Madagascar, Adansonia 37 (2), pp. 277-345 : 292-294

Canarium arcuatum Daly, Raharim. & Federman , sp. nov.

( Figs 2 ; 5 )

Small trees, leaves 2-3-jugate, rachis with only sparse to scattered hairs, stipules c. 4.2 mm long, fruits c. 4.2 × 2.5 cm, oblong, the apex rounded, the base truncate, surface with lenticels dense, relatively small, not raised, ferrugineous; distinguished from C. lamianum Daly, Raharim. & Federman , sp. nov. by the lateral leaflet base usually rounded (vs obtuse to truncate, rarely some leaflet bases acute or cordate in C. lamianum , sp. nov.), the margin often slightly revolute (vs flat), leaflet secondary veins strongly arcuate (vs spreading to nearly straight, rarely slightly arcuate), and the fruit oblong and red-beige (vs broadly (oblong-)ovoid to slightly obovoid, sometimes trigonous, and (grayish-) green to (light) brown).

TYPUS. — Madagascar. Toamasina, Island of Nosy Mangabe, 5 km S of Maroantsetra in Bay of Antongil, 15°29’S, 49°45’E, 22.II.1990 (passed f fl), B. Carlson 46 (holo-, NY!; iso-, MO, P[P00501663]!, TAN, US!) .

PARATYPI. — Madagascar. Toamasina, Nosy Mangabe , 15°29’S, 49°45’E, 22.II.1990, B. Carlson CB 46 ( MO, NY) ; Analanjirofo , 475 m, 15°24’42”S, 49°29’55”E, 10.VI.2004, P. Antilahimena AP 2483 ( NY) ; Nosy Mangabe , 300 m, 15°30’22”S, 49°45’01”E, 18.I.2006, D. C. Daly, J. Raharimampionona, J. Razanatsoa, J. Aridy & Senario 12973 ( NY) ; Analanjirofo , 400 m, 15°17’S, 49°50’E, 10.II.1988, G. E. Schatz, J. Dransfield & S. Dransfield 1873 ( MO) ; Nosy Mangabe , 0-330 m, 15°30’S, 49°46’E, 9.I.1989, G. E. Schatz & J. S. Miller 2520 ( MO, NY) ; Analanjirofo , 17°37’30”S, 49°11’30”E, 24.X.1964, Service Forestier 21912 ( NY, TEF [not seen]) .

DISTRIBUTION AND ECOLOGY. — A relatively small tree, to date confirmed only from the small island of Nosy Mangabe in the Bay of Antongil. Known to flower in Feb. and fruit in Jan.

ETYMOLOGY. — The specific epithet refers to the strongly arcuate leaflet secondary veins.

DESCRIPTION

Trees, reproductive size c. 15-16 m, with small buttresses. Leaves 19-25 cm long, 2-3-jugate; petiole 2.9-6.2 cm long, petiole and rachis with erect golden hairs to 0.5 mm, dense to scattered on rachis but often absent on petiole, also with dense to scattered snail-shaped glands; stipules 3-8 mm from petiole insertion, c. 4.2 mm long, broadly ovate (but revolute when dry), slightly constricted at base, the scar 1.5-2 mm long, surface with dense erect to appressed white hairs to 0.05 mm long; all lateral petiolules 3-9 mm long, terminal one 19-22 mm long, petiolules very slightly canaliculate, lateral pulvinuli usually inconspicuous; basal leaflets 4.4-6.7 × 2.9-4 cm, obovate or less often ovate, other laterals 5.1-10.6 × 2.1-3.8 cm, broadly ovate or less often elliptic, or slightly obovate; the terminal 5.6-10 × 2.3-4.9 cm, slightly obovate; leaflet apex usually abruptly and usually broadly short-acuminate, the acumen 2-6 mm long, leaflet base symmetrical, rounded or less often obtuse, margin usually slightly revolute; leaflets coriaceous, drying light brown, sometimes glossy abaxially when dry; secondary vein framework brochidodromous but looping at margin, secondaries in 4-7 pairs, strongly arcuate, the angle uniform, spacing sometimes decreasing toward apex and decreasing abruptly toward base; tertiaries alternate-percurrent and irregular-reticulate, perpendicular epimedial tertiaries present, quaternaries irregular-reticulate; on abaxial side the midvein broadly prominent, secondaries prominulous, rest of veins broadly prominulous, the surface with scattered snail-shaped glands; on adaxial side the midvein narrowly prominulous but sunk in a groove, rest of veins broadly prominulous to almost flat, the surface glabrous. Staminate flowers unknown. Pistillate inflorescences 7-16 cm long, with few flowers or fruits, secondary axes to 2.5 cm long, axes with dense flexuous to straight golden hairs to 0.2 mm; bracts caducous, semi-clasping (scars very broad); pedicel 4-5 × 2-3 mm, cylindrical. Pistillate flowers (only incomplete post-anthesis flowers known) c. 9-10 mm long; calyx 5.5-6 × 5.3-6 mm overall, campanulate, the lobes 2-2.5 mm long, (depressed) rounded-deltate, abaxial surface with dense de- scending thick ferrugineous hairs to 0.1 mm, adaxial surface with dense appressed whitish hairs to 0.25 mm long; petals c. 7-8 × 3.8-4 mm, ovate and slightly acuminate, with a strongly inflexed apiculum 0.25 mm long; abaxial surface with pale golden flexuous hairs to 0.5 mm long, ascending near apex and retrorse near base, adaxial surface subglabrous; androecium unknown; pistil with dense appressed whitish hairs to 0.25 mm long. Fruiting pedicel c. 6 × 3.5 mm, terete, fruiting calyx c. 3.5-4 mm long, patent, the lobes distinct. Fruit c. 4.2 × 2.5 cm, oblong, the apex rounded, the base truncate, surface with lenticels dense, small, not raised, ferrugineous, also with appressed golden hairs to 0.25 mm long, dense near apex but scattered elsewhere; mesocarp moderately thick.

NOTES

Like C. lamianum , sp. nov., C. arcuatum , sp. nov. has leaves with few juga, the petiole and rachis with only sparse to scattered hairs, stipules 3-7 mm long, and their fruits similar in size and shape, but C. arcuatum , sp. nov. can be distinguished by the stipule pubescence of fine (not thick) hairs, the petiole and rachis with long erect golden hairs to 0.5 mm long at least on the rachis (vs scattered thick, appressed golden hairs to 0.05 mm long in C. lamianum , sp. nov.), the pulvinuli usually inconspicuous (vs usually conspicuous), lateral leaflet base usually rounded (vs obtuse to truncate, rarely some leaflet bases acute or cordate), the margin often slightly revolute (vs flat), the secondary veins usually fewer (4-7 vs 6-10), abruptly crowded toward the base (vs often irregularly spaced), and strongly arcuate (vs spreading to nearly straight, rarely slightly arcuate), the infructescence more slender, and the fruit oblong and red-beige (vs broadly (oblong-)ovoid to slightly obovoid, sometimes trigonous, and (grayish-) green to (light) brown). Canarium arcuatum , sp. nov. is contrasted with C. angulatum , sp. nov. in the discussion under that species.

Figures

FIG. 2. — Canarium ampasindavae Daly, Raharim. & Federman, sp. nov.: A, leaf, with detail of leaflet (A’) and of petiole with stipular scar (A’’); B, infructescence, with detail of fruit surface (B’). From Tahinarivony et al. 179 (NY). Scale bars: A, B, 2 cm; A’’, 1 cm; A’, B’, not to scale.

FIG. 5. — Canarium arcuatum Daly, Raharim. & Federman, sp. nov.: A, flowering branchlet; B, pistillate flower; C, fruiting branchlet, with detail of leaflet (A’) and of fruit surface (A’’); D, petiole and stipules; E, cross-section of fruit; A, B, Carlson 46 (NY); C, D, Schatz & Miller 2520 (NY); E, after field photo by D. Daly. Scale bars: A, C, E, 2 cm; B, 3 mm; D, 1 cm; A’, A’’, not to scale.