Mouriri barinensis (Morley) Morley

  • Authority

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

  • Family

    Melastomataceae

  • Scientific Name

    Mouriri barinensis (Morley) Morley

  • Type

    Type. F. J. Breteler 3722 (holotype, US; isotypes, MICH, SP, U). Venezuela: Barinas: Ticoporo forest reserve near Río Michay, 70° 40 W, 7° 55 N. Immature fruit, 15 March, 1964.

  • Synonyms

    Mouriri guianensis subsp. barinensis Morley

  • Description

    Description - Tree to 35 m high with a trunk to 65 cm in diam, glabrous except for the inflorescence; young twigs 4-channelled, 4-angled, or very narrowly 4-winged; bark of older trunk grayish to brown to dark reddish, shallowly fissured, often scaling off in irregular lengthwise pieces; inner living bark pale orange, very thin and brittle; wood brown to red-brown, hard and heavy. Petioles 4.0-8.0 mm long; blades rather coriaceous, usually an intense green and shining above, lighter below, 6.0-12.0 cm long, 1.7-4.7 cm wide, ovate to ovate-elliptic to oblong-elliptic, often narrowly so, acuminate or abruptly so at the apex, rounded to acute at base; midrib slightly grooved above at least when dry, prominent below, rounded at base, usually becoming 2-angled 1/6-1/2 of the way to the apex, seldom rounded most of the way; lateral nerves visible below and usually above when dry. Midrib xylem tubular; stomatal crypts Type II, averaging in a leaf ca 37-67 p in diam, 16-20 p high, 45-87 per sq mm (extremes 22-90 p diam, 15-27 p high, 36-105 per sq mm); upper epidermis one cell thick, without mucilaginous walls; hypodermis present, with frequent mucilaginous walls; free stone cells present only in petiole base; terminal sclereids basically stellate, the central body narrow, l-3(-6) times as long as wide, with downward arms and usually with a short stout vertical branch above with arms radiating upward, giving the hourglass form found in Af. grandiflora, sometimes the sclereid approaching the columnar condition. Inflorescences in the lower leaf axils and at upper leafless nodes on twigs up to 5.0 mm thick, 1-7 per side, often densely clustered, each 1-11-flowered, 1.0-5.5 mm long to base of farthest pedicel measured along the axes and with 1-3 internodes in that length; bracts 1.0-1.8 mm long, triangular to ovate-triangular, mostly deciduous by anthesis. Axes of inflorescence, bracts, and pedicels often minutely puberulent, the flower glabrous. True pedicels 2.0-4.5 mm long; calyx light green to yellowish-green, the calyx including the inferior ovary 4.2-5.0 mm long, campanulate; free hypanthium 1.4-1.7 mm long; calyx lobes before anthesis 0.9-1.2 mm long, 2.0-2.5 mm wide, 1.0-1.4 mm long from stamen attachment, broadly rounded-triangular and often apiculate, separating at anthesis a further length of 0-0.2 mm. Petals rose or light rose, 5.0-5.3 mm long, 4.2-4.6 mm wide, trullate to ovate, acute or abruptly so at apex, the base sessile or with a claw to 0.8 mm long, the margin minutely erose. Antesepalous filaments ca 4.0 mm long, antepetalous ones ca 4.5 mm long; anthers 2.0-3.0 mm long; sporangia 1.4-2.2 mm long, dehiscing by apical pores; gland 0.4-0.9 mm long, 1.3-1.9 mm from apex of anther when measured from center of gland; cauda ca 0.7-0.8 mm long. Ovary 4-5-locular; ovules axile-basal, produced only outwardly from each placenta, 14 or 15 in all; style 9.0-11.5 mm long. Fruit edible, orange to yellowish, globose to depressed-globose, not lobed, ca 20-28 mm long and 22-30 mm in diam when dry, ca 25-35 mm high and 28-38 mm in diam when fresh (said to be up to 50 mm high), with a terminal flat round calyx scar 4.0-9.0 mm in diam and a short obconic stipe at base 1.0-3.0 mm long, the flesh ca 1 cm thick; the fruits when ca ¼-¾ full size tend to be broadest above the middle, but this form is not seen in fully ripe fruits. Seeds 2-4, medium to dark brown, 14.0-16.3 mm long, 8.3-11.6 mm wide, 6.89.2 mm thick, irregularly ellipsoid, flattened on the contact faces, with a rough roundish to half-round to elliptic hilum 1.0-2.5 mm high and 2.5-4.5 mm wide at the base facing one side.

  • Discussion

    Used locally in the construction of country houses (Rodriguez 1531).

    When first named, as a subspecies, the only known distinguishing features of this taxon were those of the fruit, seed, and stomatal crypts. As it happened, the fruit examined was immature; the differences proved to be greater when ripe fruits were sent by Dr. H. A. Rodriguez of Merida. One other difference has come to light, that of petiole length, which is greater than in M. guianensis, and which also differs in proportion: the blade is 10-20 times the petiole length in M. barinensis, 15-45 times in M. guianensis. Mouriri barinensis is the first species of the genus to come to my attention which is distinguished primarily by its fruits and seeds.

    Addendum: a recent fruiting collection from Peru raises questions which must remain unanswered for the moment. The collection is J. Schunke V. 4793, US, from Dept. San Martin, Prov. Mariscal Caceres, Dtto. Tocache Nuevo, Quebrada de Huasca Yacu (right side of the Huallaga R.), “en bosque alto,” 7 Apr 1971. The plant is a tree 20-25 m tall with a trunk 18 inches in diam, the bark peeling off in long narrow strips. The specimen bears a close resemblance to Af barinensis in having large and few stomatal crypts and large fruits with relatively large seeds. The crypts are 45-111 µ in diam, 13-18 µ high, 21-27(-36) per sq mm; the fruits are orange, 14-18 mm high and 17-22.5 mm thick when dry, ca 30 mm high and thick when fresh; and the seeds are blackish-brown and 9.3-13.6 mm long, 7.3-9.4 mm wide (tangential), and 5.8-8.2 mm thick (radial). The crypts are thus somewhat larger and fewer than those of M. barinensis, while the seeds are intermediate in size between those of M. guianensis and M. barinensis The petioles are 4.0-5.5 mm long, with a blade/petiole ratio of 15-24, figures closer to those of M. guianensis than M. barinensis.

    This plant may be a distant form of M. barinensis, possibly with populations at intermediate points yet to be discovered, or a separate taxon, or even a subspecies of Af guianensis. Flowering material is essential for a satisfactory evaluation in this case and probably more widespread collecting as well.

  • Common Names

    Perguétamo caimito, perguetamo, perhuetano, caimito

  • Distribution

    Known only from the wet forests of Barinas at 100-300 m elevation. One of the major localities, the Reserva Forestal de Caparo, is reported as having an average annual rainfall of 2000 mm and an average annual temperature of 27°C.

    Barinas Venezuela South America|