Elaeocarpus xanthodactylus A.C.Sm.
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Authority
Smith, Albert C. 1953. Studies of Pacific Island plants, XV. The genus Elaeocarpus in the New Hebrides, Fiji, Samoa, and Tonga. Contr. U. S. Natl. Herb. 30: 523-573.
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Family
Elaeocarpaceae
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Scientific Name
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Type
Type in the herbarium of the Arnold Arboretum, collected in dense forest on the summit ridge of Mt. Numbuiloa, east of Lambasa, Province of Mathuats, Vanua Levu, Fiji, alt. 500-590 m., November 3, 1947, by A. C. Smith (No. 6471). Duplicate at US.
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Description
Latin Diagnosis - Arbor ramulis petiolisque gracilibus strigoso-puberulis mox glabratis, foliorum laminis ellipticis vel obovato-lanceolatis, petalis roseis in laciniis 7 vel 8 luteis fissis, staminibus circiter 15 uniseriatis, antheris conspicue aristatis distinguenda; E. graeffei Seem. et E. uliano Christophersen aftinis, staminibus et petalorum laciniis paucioribus, foliorum laminis basi obtusis vel subacutis margine subintegris, ramulis petiolisque mox glabratis valde differt.
Description - Tree, up to 10 in. high, the young parts copiously sericeous with pale reddish hairs 0.4-0.6 mm. long, the branchlets slender, subterete, 3 mm. in diameter toward apices, strigose-puberulent distally (hairs 0.1-0.3 mm. long), glabrate; leaves spaced or somewhat congested on apical parts of brnchlets, the petioles slender, shallowly canalic-ulate, swollen at base and apex, (0.7—) 1.5-3 cm. long, sparsely strigose like young branchlets, soon glabrate; leaf-blades papyraceous or chartaceous, drying dark green, narrowly elliptic or obovate-lanceolate, (5—) 7-12 cm. long, (2--) 3-5.5 cm. broad, obtuse to subacute at base and short-decurrent on the petiole, cuspidate at apex (acumen up to 1 cm. long, callose-obtuse), narrowly recurved at margin and entire or very obscurely crenulate with remote and shallow indentations, sparsely strigose on costa above or completely glabrous, beneath strigose on costa and nerves with hairs up to 0.5 mm. long but soon glabrate, the costa plane or slightly raised above, prominent beneath, the secondary nerves 7-10 per side, spreading, curved, anastomosing toward margin, prominulous above, sharply elevated beneath, the veinlet-reticulation intricate, prominulous on both sides; racemes axillary or arising below leaves, the peduncle 1-2 cm. long, forming with the rad:his a slender axis 5-7 cm. long, this 5-10-flowered, like the pedicels puberulent or spreading-pilose, the hairs golden, 0.2-0.4 mm. long, the flower-subtending bracts lanceolate, about 1.5 mm. long, pilose on both sides like the rachis, caducous, the pedicels slender, 7-10 mm. long at anthesis; sepals 5, thin-carnose, oblong-lanceolate, 7.5-9 mm. long, 1.5-2 mm. broad, subacute, carinate within, sericeous on both sides with golden hairs 0.2-0.4 mm. long; petals 5, submembranaceous distally, slightly thickened toward base, often remaining involute at basal margins, oblong-cuneate, 9.5-10.5 mm. long, 4-4.5 mm. broad, sparsely golden-sericeous within toward base, other-wise glabrous, conspicuously fimbriate at apex with 7 or 8 lobes, these subequal, 2-3.5 mm. long, each with 1 or 2 ultimate veinlets disk carnose, 0.5-0.8 mm. high, 5-lobed, the lobes confluent, dorsally sulcate, hispidulous with golden hairs about 0.2 mm, long stamens uniseriate, 15 (in several flowers dissected), 5.5-6.5 mm. long, the filaments terete, distally minutely hispidulous, 2.2-2.7 mm, long, the anthers 3.3-3.8 mm. long, minutely hispidulous-tuberculate, terminated by a subulate dorsal awn 0.8-1 mm. long; ovary ellipsoid, puberulent-sericeous with pale golden hairs 0.1-0.3 mm. long, the style subulate, 5-16 mm. long, pilose near base, glabrous distally, the ovary-wall obscurely sericeous within, the locules 2, each with 4-6 biseriate ovules.
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Discussion
From its only close allies, E. graffei and E. ulianus, the new species is readily distinguished by its few stamens, its colored petals with comparatively few apical laciniae, by having its leaf-blades obtuse to subacute at base, and by its more readily glabrate habit. Petal-color is probably a very dependable character in Elaeocarpus, within reasonable limits, as it seems correlated with other floral characters unfortunately it is not always noted by collectors. Another specimen which suggests E. xanthodactylus is Smith 6555 (A, US), from essentially the type locality (summit of southwestern ridge of Mt. Numbuiloa, alt. about 500; tree 12 m. high, in dense forest). This specimen has leaves essentially like those of No. 6471, but the petioles are 3-6 cm. long and the base of the blade is more acute. The infructescence is greatly swollen, the pedicels 18-20 mm. long, and the persistent disk with hairs 0.3-0.7 mm. long; the flower-subtending bracts are persistent and 3-4 mm. long. Although the foliage differences are slight, I hesitate to refer No. 6555 to the new species because ordinarily, in Elaeocarpetts, the flower-subtending bracts, pedicels, and disk-indument do not lengthen much with maturity. The fruit of No. 6555 is of an unusual type; it is ellipsoid, up to 5 by 3 cm., the epicarp is tough and comparatively thick (0.3-0.4 mm. thick), the mesocarp is fibrous and apparently at least 5 mm. thick, and the endocarp is very thin, scarcely more than 0.3 mm. thick, forming an irregularly angled (not flattened) putamen. This is not the type of putamen found in other Pacific species of this alliance. More evidence is needed before this specimen can be definitely connected with E. xanthodactylus, but it obviously does not represent any other described species.