Dactyladenia jongkindii Breteler, 2000

Breteler, F. J., 2000, Novitates Gabonenses 38. Two new species of Dactyladenia (Chrysobalanaceae) from Gabon, Adansonia (3) 22 (1), pp. 117-122 : 118-122

Dactyladenia jongkindii Breteler , sp. nov.

Dactyladeniae floretii Breteler maxime simile, sed bracteolis majoribus 5-palmatilobatis ad invicem 3- palmatilobatis et pedicello infimo multo longiore differt; a speciebus aliis congeneribus stipulis saccatis differt.

TYPUS. — Breteler & Jongkind 10412, Gabon, 5-15 km NNW of Ndjolé, fl. Nov. (holo-, WAG; iso-, BR, G, K, LBV, MO, P).

Shrub to treelet, 3-6 m tall. Branches hispid mixed with a puberulous indumentum, glabrescent with age, the same indumentum present on petioles and stipules; young vegetative parts occasionally also covered by a web of white arachnoid hairs. Stipules saccate, ± ovoid in outline, (6-)10- 15(-18) mm long, 4-5 mm in diam., rather sharply narrowed at base, gradually tapering at apex, on distal side from petiole with 1-4 longstalked glands. Leaves: petiole subterete, 3-5 mm long; lamina oblong to obovate-oblong, 14-25 (-30) × 5-10 cm, 2.5-3 times as long as wide, narrowly cordate at base, acutely acuminate at apex, the acumen 0.5-1.5 cm long; glabrous above except for the slightly impressed hairy midrib, sparsely short to long-hairy beneath, mainly on the midrib and the (10-)12-15 pairs of main laterals, these plane to slightly prominent above, more distinct and prominent beneath; glands flat to slightly impressed, small, beneath only, some alongside the midrib, others more dispersed, usually more densely concentrated near base and on the acumen. Inflorescence a suberect, simple raceme, 10-15 cm long, many-flowered, puberulous; basal bracts empty, entire to pinnatifid with stalked glands near base, higher bracts with sessile glands, narrowly triangular, ± 6 × 2 mm, soon reflexed, pubescent beneath, ± glabrous above; lower pedicel 10-16 mm long, puberulous. Bracteoles subopposite to alternate, inserted 2-4 mm below apex of lower pedicel, deeply 5- palmatilobate, 4-6 mm long, lobes gland-tipped, puberulous in basal part; upper pedicel 2-3 mm long, puberulous; receptacle tube 15-17 mm long, gibbous at base, puberulous outside, glabrous inside except for some stiff hairs at mouth. Sepals spreading to reflexed, ovate-elliptic to oblong-obovate, 5-8 × 3-4 mm, tomentose inside and on the outside parts covered in bud, puberulous with some hispid hairs outside; outer sepals with up to 4 long-stalked glands on the margin. Petals early caducous, thin, white, oblong-elliptic to obovate, 11-15 × 6-7 mm, glabrous, shortly clawed. Stamens 30-33, 5- 6 cm long, glabrous, white; filaments united for ca. 3/4 of their length; anthers ellipsoid, ca. 0.6 mm long. Style slightly longer than stamens,glabrous, stigma small; ovary velutinous, ca. 1 mm long. Fruits unknown. — Figs. 2 , 3.

PARATYPES. — Gabon: Breteler & Lemmens 8410, near Libreville, ster. Oct. ( WAG); J . M . & B. Reitsma 2745, N of Malibé , ster. Dec. ( WAG) .

NOTE. — This species is named after C. C. H. JONGKIND, with whom the author collected the type specimen .

By the shape of their leaves, especially the cordate base, the simple racemes, and the glandular,

cm 2

deeply lobed bracteoles, the two new species resemble D. bellayna (Baill.) Prance & F. White , D. campestris (Engl.) Prance & F. White , and D. icondere (Baill.) Prance & F. White. The latter three species are, according to the key by which they are separated in LETOUZEY & WHITE’ s treatment of the genus (as Acioa) in the Flore du Gabon (1978: 8), closely related. Collectively they may be distinguished from the two new species by the following key:

1. Stipules ± flat, without inrolled margins; lower pedicel glabrous, (10-)15-18(-22) mm long; receptacle glabrous ...................................................................................... D. bellayana , D. campestris , D. icondere

1’. Stipules saccate; lower pedicel puberulous, (2-) 4-16 mm long; receptacle puberulous, when sparsely so or nearly glabrous then bracteoles 3-palmatilobed .......................................................................................... 2

2. Stipules with distinct, densely pubescent margins, without stalked glands at base ( Fig. 1C ); lower pedicel 2-7 mm long; bracteoles 3-lobed, 1-2 mm long .................................................................................. D. floretii

2’. Stipules without densely pubescent margins, ± evenly hairy, with stalked basal glands ( Fig. 3B ); lower pedicel 10-16 mm long; bracteoles 5-partite, 4-6 mm long ................................................................ D. jongkindii

Figures

Fig. 2. — Distribution of Dactyladenia floretii (•) and D. jongkindii (*).

Fig. 3. — Dactyladenia jongkindii: A, flowering branch; B, stipules; C, flower; D, calyx; E, bracteole. (A, C-E, Breteler & Jongkind 10412; B, Breteler & Lemmens 8410). Drawing by H. de VRIES.

Fig. 1. — Dactyladenia floretii: A, leafy branch with erect inflorescences; B, inflorescence; C, stipule; D, flower; E, bracteole; F, fruit. (A, C-E, Breteler et al. 14435; B, F, Breteler et al. 14490). Drawing by H. de VRIES.