Monographs Details:
Authority:
Morley, Thomas. 1976. Melastomataceae tribe Memecyleae. Fl. Neotrop. Monogr. 15: 1-295. (Published by NYBG Press)
Morley, Thomas. 1976. Melastomataceae tribe Memecyleae. Fl. Neotrop. Monogr. 15: 1-295. (Published by NYBG Press)
Family:
Melastomataceae
Melastomataceae
Description:
Description - Glabrous shrub 1-3 m high; young twigs narrowly 4-winged. Leaves sessile; blades thick, coriaceous, (3.5-)6.0-10.0 cm long, (2-)3.0-6.0 cm wide, ovate to oblong-ovate, rather abruptly acuminate at about the apical 5 mm, rounded and shallowly cordate at base with a notch 2.0-3.0 mm deep; midrib grooved above, low-rounded below at base, becoming nearly or fully plane above the base; lateral nerves and an arcuate submarginal nerve invisible or faintly visible above and invisible or rarely faintly visible below when dry, narrowly and shallowly grooved when visible, invisible when fresh. Margins of midrib xylem turned up, in and slightly down at the very edges; stomatal crypts a highly modified Type II, averaging in a leaf ca 31-33 µ in diam, 105-120 µ high, 90-95 per sq mm (extremes 22-50 µ diam, 90-140 µ high, 75-110 per sq mm); upper epidermis mostly two cells thick, cells of the outer layer often paired with a single one of the inner layer, cells of the inner layer with frequent to no mucilaginous walls, rarely the epidermis one cell thick in a few places; hypodermis none except near the midrib; free stone cells above and below the midrib xylem extending less than ¼ of the way to the midrib tip; terminal sclereids Filiform, running vertically between the epidermises and turning abruptly there and spreading out horizontally and usually branching; floral terminal sclereids short-filiform, occasional in calyx lobes, rare in petals, otherwise absent. Inflorescences in the axils of the upper leaves, 1-3 per axil, each 1-5-flowered, 2.1-28.0 mm long to the base of the farthest pedicel measured along the axes and with 2-3 internodes in that distance; bracts 3.0-8.4 mm long, 1.2-2.0 mm wide, lanceolate, persistent or not at anthesis, deciduous before fruit maturation. True pedicels 2.4-6.0 mm long; calyx including inferior ovary 3.3-4.1 mm long, broadly campanulate; free hypanthium ca 0.4-0.6 mm long; calyx lobes 1.2-1.5 mm long, 2.3-3.2 mm wide, 1.8-2.3 mm long from the stamen attachment, broadly triangular to rounded-triangular and apiculate with an outer central ridge in the point, erose on the margins, the calyx not splitting between the lobes at anthesis. Petals white, 7.5-12.5 mm long, 4.0-6.5 mm wide, oblong-ovate to oblong or slightly obovate-oblong, attenuate-acute to abruptly acuminate at the apex, sessile, densely granulate on both sides, often splitting a short distance on each side near the base (perhaps in drying) producing 2 short basal lobes. Filaments pink, the antesepalous ones ca 7.5-8.5 mm long, the antepetalous ones ca 8.5-10.0 mm long; anthers purple, 3.4-3.8 mm long; sporangia curving over apex of anther and extending a short distance down the side of the gland, 2.3-2.8 mm long on the side opposite the gland, 0.7-0.8 mm long on the gland side, dehiscing by lengthwise slits, these widest at the apex; gland 1.5-1.7 mm long, 1.7 mm from apex of anther when measured from center of gland; cauda 1.0-1.4 mm long. Ovary 5-locular; placentae basal in each locule, the ovules borne on all sides of a short basal column, 4 or 5 per placenta, 20-22 in all; style 13.0-19.0 mm long, 0.6-0.75 mm thick, hooked upward at the tip, with a pointed stigma 0.3 mm in diam. Fruit pale orange, depressed-globose, crowned by the persistent calyx, 6.5-7.0 mm high excluding calyx and 8.0-10.0 mm in diam when dry, estimated 7.0-9.0 mm high and 9.8-12.5 mm in diam when fresh. Seeds 3-5, light brown, 5.3-6.8 mm long, ca 3.9-5.4 mm wide, 2.7-4.0 mm thick, irregularly obovoid with the thick end up, the hilum lateral, flattish, elliptic, covering most of the broad side of the seed, 5.0-6.3 mm high, 3.4-5.0 mm wide.
Description - Glabrous shrub 1-3 m high; young twigs narrowly 4-winged. Leaves sessile; blades thick, coriaceous, (3.5-)6.0-10.0 cm long, (2-)3.0-6.0 cm wide, ovate to oblong-ovate, rather abruptly acuminate at about the apical 5 mm, rounded and shallowly cordate at base with a notch 2.0-3.0 mm deep; midrib grooved above, low-rounded below at base, becoming nearly or fully plane above the base; lateral nerves and an arcuate submarginal nerve invisible or faintly visible above and invisible or rarely faintly visible below when dry, narrowly and shallowly grooved when visible, invisible when fresh. Margins of midrib xylem turned up, in and slightly down at the very edges; stomatal crypts a highly modified Type II, averaging in a leaf ca 31-33 µ in diam, 105-120 µ high, 90-95 per sq mm (extremes 22-50 µ diam, 90-140 µ high, 75-110 per sq mm); upper epidermis mostly two cells thick, cells of the outer layer often paired with a single one of the inner layer, cells of the inner layer with frequent to no mucilaginous walls, rarely the epidermis one cell thick in a few places; hypodermis none except near the midrib; free stone cells above and below the midrib xylem extending less than ¼ of the way to the midrib tip; terminal sclereids Filiform, running vertically between the epidermises and turning abruptly there and spreading out horizontally and usually branching; floral terminal sclereids short-filiform, occasional in calyx lobes, rare in petals, otherwise absent. Inflorescences in the axils of the upper leaves, 1-3 per axil, each 1-5-flowered, 2.1-28.0 mm long to the base of the farthest pedicel measured along the axes and with 2-3 internodes in that distance; bracts 3.0-8.4 mm long, 1.2-2.0 mm wide, lanceolate, persistent or not at anthesis, deciduous before fruit maturation. True pedicels 2.4-6.0 mm long; calyx including inferior ovary 3.3-4.1 mm long, broadly campanulate; free hypanthium ca 0.4-0.6 mm long; calyx lobes 1.2-1.5 mm long, 2.3-3.2 mm wide, 1.8-2.3 mm long from the stamen attachment, broadly triangular to rounded-triangular and apiculate with an outer central ridge in the point, erose on the margins, the calyx not splitting between the lobes at anthesis. Petals white, 7.5-12.5 mm long, 4.0-6.5 mm wide, oblong-ovate to oblong or slightly obovate-oblong, attenuate-acute to abruptly acuminate at the apex, sessile, densely granulate on both sides, often splitting a short distance on each side near the base (perhaps in drying) producing 2 short basal lobes. Filaments pink, the antesepalous ones ca 7.5-8.5 mm long, the antepetalous ones ca 8.5-10.0 mm long; anthers purple, 3.4-3.8 mm long; sporangia curving over apex of anther and extending a short distance down the side of the gland, 2.3-2.8 mm long on the side opposite the gland, 0.7-0.8 mm long on the gland side, dehiscing by lengthwise slits, these widest at the apex; gland 1.5-1.7 mm long, 1.7 mm from apex of anther when measured from center of gland; cauda 1.0-1.4 mm long. Ovary 5-locular; placentae basal in each locule, the ovules borne on all sides of a short basal column, 4 or 5 per placenta, 20-22 in all; style 13.0-19.0 mm long, 0.6-0.75 mm thick, hooked upward at the tip, with a pointed stigma 0.3 mm in diam. Fruit pale orange, depressed-globose, crowned by the persistent calyx, 6.5-7.0 mm high excluding calyx and 8.0-10.0 mm in diam when dry, estimated 7.0-9.0 mm high and 9.8-12.5 mm in diam when fresh. Seeds 3-5, light brown, 5.3-6.8 mm long, ca 3.9-5.4 mm wide, 2.7-4.0 mm thick, irregularly obovoid with the thick end up, the hilum lateral, flattish, elliptic, covering most of the broad side of the seed, 5.0-6.3 mm high, 3.4-5.0 mm wide.
Discussion:
Although relatively primitive in several respects, as noted in the discussion of the section, the sessile cordate leaves of M. uncitheca seem to represent a specialization.The species does not appear to be very closely linked to any other member of the section.
Although relatively primitive in several respects, as noted in the discussion of the section, the sessile cordate leaves of M. uncitheca seem to represent a specialization.The species does not appear to be very closely linked to any other member of the section.
Distribution:
Amazonas Venezuela South America|
Amazonas Venezuela South America|