Myrcia dichasialis McVaugh
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Authority
Maguire, Bassett. 1969. The botany of the Guayana Highland-part VIII. Mem. New York Bot. Gard. 18: 1-290.
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Family
Myrtaceae
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Scientific Name
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Description
Species Description - A shrub or small tree up to 5-6 m high, the vegetative buds, young branchlets and the inflorescence appressed-pubescent with pale hairs; hypanthium densely strigose with nearly colorless hairs, the calyx very sparingly strigose outside, its lobes densely pubescent inside and on the margins; leaves soon glabrous or sparingly strigose beneath, lance-ovate, usually broadest well below the middle, 7-14 cm long, 2-4 cm wide, 2.5-4 times as long as wide, gradually long-acuminate at apex, acute or rounded at base, the margins passing abruptly onto the acute inner angles of the deeply channeled reddish petiole 4-7 mm long, 1-1.5 mm thick; midvein evidently channeled and somewhat impressed above; lateral veins numerous and parallel, straight, ascending, elevated shghtly on both sides when dry; marginal vein about as strong as the laterals and somewhat arched between them, 1-2 mm from the margin; small veins forming an elevated reticulum on both surfaces; leaves lustrous above, with few or many pale glands evident on both surfaces; inflorescence up to 6-7 cm long, few-flowered, once or twice compound, the main branchlets of the panicle often appearing racemose, bearing 2-4 pairs of lateral flowers on stout pedicels l-3(-5) mm long, 0.5 mm thick; bracts and bracteoles deciduous before anthesis; buds 3-4 mm long, subglobose or broadly turbinate, the hypanthium broadly conic; calyx-lobes 5, subequal, ovate-deltoid or suborbicular, obtuse, up to 2-2.5 mm long and wide, widest above the base and imbricate where widest, in anthesis not reflexed but irregularly wrinkled, erect or somewhat spreading, not separating but the sinuses conspicuous; disk flat, short-hirsute on the margins, pubescent at center, 2.5-3 mm wide; style 7-8 mm long; stamens about 200, about as long as the style; petals ovate, 4.5-5 mm long and wide; mature fruit not seen, probably ellipsoid, black; ovary bilocular, with 2 ascending ovules in each locule.
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Discussion
Berg (Linnaea 31: 251. 1862) cited Spruce 3495, from Rio Guainia above the mouth of the Casiquiare, as Myrcia spruceana, but this collection seems actually to represent M . dichasialis (CGE, F, M I C H ) . The type of M . spruceana is referable to M . fallax. Spruce 3495 has large calyx-lobes pubescent within, and leaves rather abruptly rounded and definitely broadest near the base. A species described from Duida, Myi'cia compressa Gleason (Bull. Torrey Club 58: 410. 1931), of which I have seen the type (Tate 834) at N Y , is similar but probably represents another taxon; in the type the inflorescence and the hypanthium are rusty-velutinous, in contrast to those of M . dichasialis in which these structures are pale, even if densely strigose. Venezuelan material of Myrcia dichasialis is distinguishable from Peruvian, but I do not believe it represents another species, although relatively few species of Myrtaceae are known both from the lowlands of the upper Amazon and those of the upper Orinoco. In the type {Schunke 134, at F) and other specimens cited in the Flora of Peru (Field Mus. Publ. Bot. 13(4): 636. 1958), the lateral veins of the leaves diminish distally, so that a marginal vein is hardly recognizable as such; the lateral flowers near the tips of the panicles are on pedicels 2-6 m m long; the calyx-lobes are 1.5-2 m m long (a httle shorter than in Venezuelan specimens), and the floral disk is 3-4 m m wide (a little wider than in Venezuelan specimens).