Canarium laxiflorum 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 : 316

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

( Figs 1, 19 )

Medium-sized tree, leaves 4-5-jugate, leaflets chartaceous, secondary veins in 5-9 pairs and arcuate; distinguished from C. pulchrebracteatum Guillaumin by the stipules 5-13(23) (vs 18-20) mm from petiole insertion, lateral leaflets usually laterals elliptic to obovate (vs narrowly oblong(-elliptic) to oblanceolate in C. pulchrebracteatum ), the leaflet apex narrowly (vs broadly) acuminate, midvein on the the abaxial leaflet surface with stiff erect hairs (vs ascending to appressed hairs), staminate inflorescences c. 34 (vs 7-19) cm long, bracteoles ovate to (narrowly) elliptic (vs almost linear), and flowers longer (10-13.5 vs 7.6-8 mm). TYPUS. — Madagascar. Toamasina, S du Campement de Tampolo, 17°17’S, 49°25’E, 21.X.2001, R. Rabevohitra, F. Breteler & J. Aridy 3985 (holo-, P[P00501630]!; iso-, TEF).

DISTRIBUTION AND ECOLOGY. — Canarium laxiflorum , sp. nov. is known only from the type, a relatively large tree collected in wet (sub)littoral forest near Tampolo in Fénérive Est , Toamasina .

COMMON NAME. — Ramy.

ETYMOLOGY. —The specific epithet refers to the long, laxly branched inflorescences.

DESCRIPTION

Trees, reproductive size c. 20 m × 25 cm diam. Leaves 13.6- 31 cm long, 4-5-jugate; petiole 4-9 cm long, petiole and rachis with sparse to scattered, erect to ascending, white hairs to 0.15 mm long, also scattered snail-shaped glands; stipules caducous, 18-20 mm from petiole insertion, the scar 2 mm long; all lateral petiolules 5-11 mm long, terminal one 22-25 mm long; basal leaflets 6-7 × 2.8-3.6 cm, ovate or broadly elliptic, other laterals 6.1-10.1 × 2.5-3.6 cm, narrowly oblong-elliptic to oblanceolate, terminal one 8-9.4 × 3.1-3.3 cm, oblanceolate; leaflet apex abruptly and broadly short-acuminate, the acumen 3-9 mm long; lateral leaflet base symmetric, cuneate to rounded; margin slightly revolute; leaflets chartaceous, drying dark brown abaxially, dark grayish brown adaxially, dull or adaxial side slightly glossy; secondary vein framework weakly festooned-brochidodromous, secondaries in 5-9 pairs, arcuate, spacing and angle decreasing toward base, 1-2 perpendicular epimedial tertiaries per pair of secondaries, intercostal tertiary venation irregular-reticulate and alternate-percurrent, quaternaries mixed regular- and irregular-polygonous with some admedial branching; on abaxial side all veins prominent and discolorous, the surface papillate and with scattered white hairs to 0.15 mm long on the midvein, rest of surface glabrous; on adaxial side all veins prominent, with a few scattered white hairs to 0.15 mm long on midvein and at base and a few on secondary veins, or glabrous. Staminate inflorescences terminal, c. 34 cm long, c. 3.8 mm diam at base, secondary axes to 10 cm long, axes with dense to sparse, fine, flexuous, ferrugineous hairs to 0.2 mm long; bracts on primary axis to 4 mm long, ligulate; bracteoles c. 1-3.4 mm long, sublinear to subulate, shorter than the buds, with flexuous hairs to 0.2 mm long; pedicel 1-1.7 × 0.8-1 mm. Staminate flowers 7.6-8 mm long; calyx 2.8- 3.1 × 4.5-4.8 mm overall, cupular, taller than ovariodisk, lobes 0-0.6 mm long, rounded depressed-deltate; petals 6.6- 7.2 × 3.7 mm, exposed part longer than calyx, (oblong-) ovate, with an inflexed apiculum 0.4-0.5 mm long, abaxial surface with dense, mostly retrorse-appressed, golden hairs to 0.2 mm long; stamens inserted at base of ovariodisk, antesepalous stamens 3.2-3.7 mm long, the antepetalous ones 2.8 mm long, anthers 2-2.3 mm long, (ovate-)oblong; ovariodisk 0.8-1.9 × 0.7-3.8 mm (variable in flowers on same inflorescence), essentially discoid to essentially obovoid, with craggy apex.

NOTES

Like C. lamianum , sp. nov., C. laxiflorum , sp. nov. has the stipules 3-10 mm long and the stipular scar longer than 1.5 mm, and the leaflet secondary veins in 5-10 pairs. The latter can be distinguished by the staminate inflorescences c. 34 (vs 7-19) cm long, the secondary axes densely branching distally, the bracts ligulate to subulate or linear and shorter than the buds (vs ovate and foliose and longer than the buds), and Canarium laxiflorum , sp. nov. is similar to C. pulchrebracteatum but contrasted with it in the discussion under the latter species. Razakamalala 2416 (NY) may represent a pistillate-flowering specimen of C. laxiflorum , sp. nov., but there are enough differences that we reserve judgment at this point. This specimen has 1-3-jugate leaves; on the abaxial leaflet surface the midvein and secondaries have scattered thick appressed hairs to 0.05 mm long; the inflorescence has dense ascending to appressed golden hairs to 0.2 mm long plus capitate glands; and the calyx and petals have dense thick appressed golden hairs to 0.1 mm long plus capitate glands. Moreover, it is from Fort-Dauphin, i.e., the other extreme of the country.

Figures

FIG. 19. — Canarium laxiflorum Daly, Raharim. & Federman, sp. nov.: A, branchlet with staminate buds, with detail of leaflet margin (A’) and detail of petiole and stipular scars (A’’); B, detail of inflorescence; C, lateral view of staminate bud with bracteole (left); D, adaxial view of petal; E, lateral view of staminate bud with one petal and part of calyx removed; F, androecium and ovariodisk (left), ovariodisk (right); G, ventral and dorsal views of stamen; A-G, Rabevohitra et al. 3985 [P00501630]. Scale bars: A, 2 cm; A’’, 5 mm; B, 1 cm; C-F, 2 mm; G, 1 mm; A’, not to scale.