Myrcia grandis McVaugh

Authority

Maguire, Bassett. 1969. The botany of the Guayana Highland-part VIII. Mem. New York Bot. Gard. 18: 1-290.

Family

Myrtaceae

Scientific Name

Myrcia grandis McVaugh

Description

Latin Diagnosis - Frutex vel arbor mediocris 3-4(-7)-metralis, fere glaber, ramulis novellis et inflorescentiae ramulis majoribus pilis albidis appressis inaequaliter dibrachiatis obsitis; pedicelli floresque glabri; folia lanceolata vel ovata, infra medium latiora, sensim acuminata, 3-10 cm longa, 1-3.5 cm lata, plerumque 2.5-3-plo longiora quam latiora, basi rotundata vel subacuta, petiolis 3-5 mm longis, nervo medio supra convexo, venis laterahbus circa 20 inconspicuis; inflorescentiae 3-6 cm longae, pedunculis fere nullis, ramulis infimis 3-6 cm longis, usque ad 30-floris; alabastra 2-2.3 mm longa pyriformia, hypanthio intus glabro; calycis lobi 4 subaequales 1.3-2 mm longi, post anthesin reflexi, inter se non fissi; discus 2 mm latus; stylus 4.5 mm longus; stamina circa 35; ovarium biloculare, loculis biovulatis. Species amico C. Diego Legrand montevidensi, Myrtacearum investigatori clarissimo, nominavi.

Description - A shrub or small tree 3-4(-7) m high, glabrous except the vegetative buds (densely), young branchlets (sparsely) and major branches of the inflorescence (sparsely) beset with whitish appressed and very unequally dibrachiate hairs up to 0.5 mm long; pedicels and flowers glabrous (the calyx-lobes ciliate); leaves lanceolate or ovate, (3-)5-7(-10) cm long, (l-)1.5-3(-3.5) cm wide, (2-)2.5-3.5 times as long as wide, broadest well below the middle and tapering to the tip, gradually acuminate, the acumen obtuse, very short or usually slender, the leaves often subcaudate; blades rounded or subacute at base, shortly decurrent on the inner angles of the petiole 3-5 mm long, 1 mm or less in diam; midvein convex its whole length above, or flat near the base of the blade, where 0.5-0.8 mm wide; lateral veins numerous and parallel, more than 20 but the number indeflnite, inconspicuous, slightly elevated on both surfaces in dried leaves; marginal vein about equaling the laterals and slightly arched between them, usually 1 mm or less from the margin; upper leaf-surface lustrous, the lower paler, both rather thickly dotted with convex translucent glands; inflorescence 3-6 cm long, with many slender branches, 3(-4)-times compound; peduncle very short, the long lowermost panicle-branches (3-6 cm long, bearing up to 35 slender-pedicellate flowers) arising at the very base of the inflorescence; bracts glabrous, linear, 1-2 mm long, falling before anthesis; buds 2-2.3 mm long, shortstipitate, pyriform, the hypanthium campanulate, 1 mm long, prolonged 0 5 mm beyond the summit of the ovary; calyx-lobes 4, oblong-oval, obtuse or erose at apex. 1.3-1.5 mm long and wide, subequal or one pair longer, 1.5-2 mm long, all reflexed at anthesis but remaining attached at base; disk 2 mm wide, somewhat quadrate; style 4.5 mm long; petals suborbicular, 2 mm long; stamens about 35, 3-4 mm long, the anthers 0.3 mm long; fruit globose, turning reddish, ripening purple-black, about 5 mm in diam; embryo myrcioid; ovary bilocular, with 2 ascending ovules in each locule.

Discussion

This species is anomalous in Myrcia because of the 4-merous flowers and the presence of dibrachiate hairs, but it would be quite out of place in Marlierea because of the large calyx-lobes which remain permanently united at base.

The following specimens would key out to Myrcia grandis, but probably represent two different undescribed species.

1) Plant glabrous, with narrowly elliptic willow-like leaves acute at both ends, 5-7 cm long, 1-1.5 cm wide; midvein flat or convex above; immature, subglobose fruits with 4 broad thin calyx-lobes, borne on pedicels 2-5 m m long in raceme-like inflorescences 4-5 cm long, each raceme with 2-3 pairs of flowers. BRITISH GUIANA. Southern Pakaraima Mountains, Sukabi River below Ando Falls, elev 2200 ft, 16 Sep 1961 (imm fr), Maguire et al 46172A (MICH). 2) Plant glabrous, with broadly ovate to ovate-lanceolate, sharply acuminate leaves 6-12 cm long, 3-5 cm wide, rounded at base, abundantly pellucid-punctate; midvein convex above; flowers few in short panicles 1.5-2.5 cm long; hypanthium more or less explanate in anthesis but not splitting, the 4 broad thin calyx-lobes not deciduous.

V E N E Z U E L A . Amazonas: Esmeralda, upper Orinoco, elev 143 m, 13 M a y 1942 (past fl), Williams 15306 (F), 14 M a y 1942 (past fl), Williams 15356 (F).

Distribution and Ecology: Venezuela. Amazonas: Rio Siapa, Casiquiare, elev 100-130 m, 9 Feb 1954 (fl), Maguire et al 37617 (MICH, type), 37627 (MICH), (imm fr), Maguire et al 37658 ( M I C H ) ; Rio Guainia, Cafio San Miguel, elev 125 m, 26 Mar 1942 (imm fr), Williams 14896 (F); Rio Guainia, Maroa, elev 127 m, "2/11" 1942 (imm fr), Williams 14299 (F); Sanariapo, elev 140 m, 22 May 1940 (imm fr), Williams 13057 (F), elev 120 m, "2/7" 1942 (imm fr), Williams 15949 (F); Cerro Sipapo (Paraque), near Base Camp, elev 200 m, 8 Feb 1949 (fl), Maguire & Politi 28970 (MICH); Rio Casiquiare above mouth of Rio Pacimoni, elev 300 m, 19 Apr 1953 (bud), Maguire & Wurdack 35728 (MICH). BRITISH GUIANA. Basin of Essequibo R., near mouth of Onoro Creek, 15-24 Dec 1937 (fl). Smith 2666 (K, N Y ) . BRAZIL. Amazonas: Manaus, Ponta Negra, baixo Rio Negro, 30 Dec 1960 (imm fr), Rodrigues & Coelho 2031 [INPA 8407] (MICH), 3 Jan 1961 (fl), Rodrigues & Coelho 2042 [INPA 8420] (MICH).

Distribution

Venezuela South America|