Mouriri vernicosa Naudin

  • Authority

    Morley, Thomas. 1976. Melastomataceae tribe Memecyleae. Fl. Neotrop. Monogr. 15: 1-295. (Published by NYBG Press)

  • Family

    Melastomataceae

  • Scientific Name

    Mouriri vernicosa Naudin

  • Type

    Type. French Guiana, Cayenne. In flower; no date, J. Martin sn (holotype, P; isotypes, F, Fl (mixed specimen), G, GH, K, L, MIN, NY, US; probable isotype, BM).

  • Description

    Description - Shrub or tree to 25 m high with a trunk to 35 cm or more in diam, glabrous except for the inflorescence; young twigs terete; bark of branches brownish-gray; bark of trunk whitish, reddish-white, or brown if very old, a little fissured; wood white. Petioles 2.0-6.0 mm long; blades when dry rather smooth and a bit shiny above, dull beneath, dark, 6.2-15.0 cm long, 2.2-6.0(-7.6) cm wide; ovate to ovate-elliptic, acuminate or abruptly so at the apex, acute to rounded or rarely truncate at base and abruptly attenuate into the petiole; midrib grooved above, rounded below or becoming 2-angled 1/5 or more of the way to the apex; lateral nerves and sometimes an arcuate sub-marginal nerve raised when dry, sometimes depressed along the center. Margins of midrib xylem incurved, close together near base of petiole, ordinarily free but sometimes fusing briefly and then separating again, the xylem abnormally tubular (Rodrigues 8055, 8605, 8680), xylem of lateral veins varying from nontubular to tubular; stomatal crypts Type II, averaging in a leaf ca 23-40 µ in diam, 20-45 µ high, 62-170 per sq. mm (extremes 15-50 µ diam, 19-50 µ high, 50-180 per sq mm); hypodermis consistently present (except in Krukoff 1371, 1407), of one cell layer; mucilage walls none; free stone cells present only in base of petiole; terminal sclereids from roundish or rectangular with or without short to medium blunt arms, to columnar, typically the central body bearing 0-few horizontal arms and 1 or 2 columnar arms, the latter typically branching as they approach the epidermis but not spreading out horizontally except sometimes beneath the upper epidermis, some leaves with all sclereids columnar. Inflorescences 1-3 in the axils or at each side of leafless nodes of twigs up to 3.0 mm thick, each 1-13-flowered, 4.0-15.0 mm long to base of farthest pedicel measured along the axes and with 3-5 internodes in that length; bracts 0.7-1.2 mm long, triangular, acute to usually short-acuminate at apex, persistent in fruit; axes of inflorescence and bracts minutely puberulent except usually for the lowest ones, these glabrous. Flowers fragrant. True pedicels glabrous, 0.6-2.5 mm long; calyx including inferior ovary yellow to green, glabrous, 3.2-4.0 mm long, obconic to slightly campanulate; free hypanthium 1.2-1.7 mm long; calyx lobes low-rounded and apiculate to nearly truncate, 0.3-0.8 mm high, 1.6-2.2 mm wide, 0.7-1.1 mm long when measured from stamen attachment, the calyx splitting between the lobes at anthesis for a distance of 0-0.2 mm. Petals yellow to orange or sometimes white, ovate-oblong, elliptic-oblong, or slightly obovate-oblong to elliptic, acute to abruptly short-acuminate at the apex, truncate and unclawed at base, 4.5-6.5 mm long, 2.7-4.0 mm wide. Filaments yellow, the antesepalous ones 3.5-6.0 mm long, the antepetalous ones 5.0-8.5 mm long; anthers yellow-orange to orange, 2.9-3.7 mm long; sporangia (1.5-)1.8-2.3 mm long, dehiscing by elongate apical pores; gland 1.4-2.0 mm long, 1.4-1.8 mm from apex of anther when measured from center of gland; cauda ca 0.8-1.4 mm long. Ovary 2-locular; ovules axile, all at the same level, 9-13 in all; style 10.0-14.0 mm long. Fruit orange, globose to ellipsoid, obovoid, or ovoid, usually abruptly narrowed at base into a short stipe, sometimes also abruptly narrowed at apex, ca 15-37 mm long and 15-28 mm thick when dry, estimated 18-45 mm long and 18-34 mm thick when fresh, usually with 10 ridges extending part or all the way up the sides from the base but the ridges sometimes few or indistinct or none. Seeds 1-3, roundish if 1, plano-convex or with 2 flat faces if 2 or 3 respectively, 11.8-15.0 mm high, 9.2-13.0 mm wide, 6.3-11.0 mm thick, the polished face narrow, 8.0-17.0 mm high (measured along the surface), broadest at apex where it is 2.6-6.0 mm wide and often roundish, abruptly narrowed below; remainder of surface of outer seed face slightly rugose; seeds probably larger in large fruits.

  • Discussion

    Fruits of this species vary strikingly in the ribbing of the outer wall. In French Guiana the fruits have 9 or 10 very prominent ribs extending the whole length of the fruit (Fig 18Ja,b). Away from French Guiana, however, the ribs tend to be less prominent, are often fewer, and may extend only part of the way toward the apex from the base, being scarcely noticeable in some cases (Fig 18Jc). The limited information presently available suggests that the situation is clinal, with the ribbing becoming less pronounced as one goes farther from French Guiana. In Froes 32303, for example, from the Rio Xingu ca 770 km from Cayenne, the ribs are small and narrow; 5 or 6 of them reach the apex but the others become indistinct ca 3/4 of the way up. In Froes 23370, from Remansão on the Rio Tocantins ca 1050 km from Cayenne, the fruits which were unfortunately immature showed ridges only on the lower 1/3 of the fruit. The fruits on the collection Maguire & Politi 29011, also immature, had indistinct ridges, apparently present on the lower 1/3; this collection is from Amazonas, Venezuela, ca 1650 km from Cayenne. In Baldwin 3203, from the upper Rio Negro ca 1700 km from Cayenne, only 3 ridges can be found on the fruit, low and narrow, running ca 3/4 of the way to the apex; in fruits of Schultes & Cabrera 15510, from Colombia, Amazonas, ca 2000 km from Cayenne, there are 10 very low ridges on the fruit visible 3/4 of the way to the apex. Immature fruits from French Guiana show ridges as distinct as on the ripe fruit, therefore the ridging of other immature fruits should be at least somewhat indicative of the form of the mature fruit. Further collecting will be necessary to resolve this problem. The French Guiana fruits are so distinctive that one wonders if they could represent a separate taxon; however, floral characters do not suggest it.

    Collections from two localities show unusual conditions for the species. Rodrigues 8055, 8605, and 8680, all from the same tree in the Reserva W. Egler east of Manaus, have leaves with a tubular midrib xylem, relatively short anther sporangia, and fruits with grooves rather than ridges, the grooves plainest at the apex rather than the base. This puzzling tree has most of the characters of M. vernicosa, but is abnormal in the respects noted, for what reason is unknown at the moment. The grooved fruit suggests a related species, M. sagotiana; perhaps this much variation is to be expected in fruits of M. vernicosa, or perhaps the grooved aspect would become more ridged in appearance at maturity, for these fruits were immature. Similar collections from different localities would suggest this to be a separate species.

    The two Krukoff collections 1371 and 1407 from Rondonia also have unusual features for M. vernicosa. A hypodermis is lacking in the leaf, and again the fruit is grooved instead of ridged, in this case the grooves running all the way from base to apex. Fruits and seeds are small, the former 11.0-16.0 mm high, the latter 5.0-6.5 mm high. A loose flower found in the pocket of the Kew specimen is of the M. vernicosa type but bears a fine puberulence on the upper half of the calyx (including the inferior ovary). Arcuate submarginal nerves occur in the leaves as in M. sagotiana, a feature found occasionally in normal plants of M. vernicosa. If the loose flower with the Kew specimen belongs to it, and if all these characters are consistent in further collections, plants of that area could be considered a separate taxon.

  • Common Names

    Marakana koewa, kromokoe, Oco-imoucara , Mamãozinho, creolin

  • Distribution

    Venezuela in Amazonas; Surinam; French Guiana; Colombia in Vaupés; Brazil in Amazonas, drainages of the Rio Uaupés, Rio Negro, and Rio Solimões, and forests east of Manaus; in Roraima; in Rondonia, the Machado River drainage; in Para, the Amazon drainage within 100 km of the river, and up the Tocantins to 6° S; in Amapa; and in northwest Maranhão. Moist forests above or below flood level, commonly on stream banks, below 200 m elevation.

    Suriname South America| Vaupés Colombia South America| Amazonas Venezuela South America| French Guiana South America| Amazonas Brazil South America| Roraima Brazil South America| Rondônia Brazil South America| Pará Brazil South America| Maranhão Brazil South America| Amapá Brazil South America| Mato Grosso Brazil South America|