Conostegia macrantha O. Berg ex Triana, 1871

Kriebel, Ricardo, 2016, A Monograph of Conostegia (Melastomataceae, Miconieae), PhytoKeys 67, pp. 1-326 : 74-76

Conostegia macrantha O. Berg ex Triana Fig. 86

Conostegia macrantha O. Berg ex Triana, Trans. Linn. Soc. London 28: 97. 1872. Type: Costa Rica. San José: Candelaria, no date, A. Oersted 12 (lectotype: BR!, designated here; isolectotypes (fide Schnell (1996): C, GH, as well as a photo of a lost specimen from B at F!).

Description.

Trees 3.5-15 m tall with thick tetragonal and ridged stems that are glabrous or furfuraceous on new growth with sessile stellate trichomes; the nodal line conspicuous and sometimes setulose in young branches, lenticellate abaxially. Petioles 1-7 cm long. Leaves of a pair equal to somewhat unequal in length. Leaf blades 6.7-30 × 2.3-15 cm, 5 nerved or slightly plinerved, ovate to elliptic, the base acute to obtuse, the apex obtuse and acute to acuminate, the margin entire or denticulate, adaxially glabrous, abaxially with branched and stellate hairs on the veins. Inflorescence a terminal panicle 6-21.2 cm long branched above the base but sometimes appearing branched at the base because of multiple inflorescences arising at opposing meristems at the terminal node, accessory branches present, rachis tetragonal, accessory branches present, bracts early deciduous or absent, the rachis glabrous or furfuraceous with sessile stellate trichomes these sometimes minute and inconspicuous, bracteoles linear, ca. 2 mm long, deciduous. Pedicels 4-15 mm, frequently nodding. Flowers 7-10 merous, calyptrate. Floral buds 8-15 × 7-13.5 mm, spherical, the base rounded, the apex rounded and mucronate, not constricted, the hypanthial and calycine portions little differentiated; hypanthium 9.5-10 × 13-14 mm, glabrous or beset with small sessile stellate trichomes, strongly tuberculate. Petals 9.5-16 × 12-14.5 mm, white, obovate, spreading, the apex retuse, glabrous. Stamens 28-45, 9-11 mm long, radially arranged around the style, occasionally secondarily zygomorphic resulting from some stamen getting stuck below the stigma, the filament 5.25-5.7 mm, white, anthers 4.5-5 × 1.75-2.25 mm, oval, yellow, the base sagittate, strongly laterally compressed, the pore 0.2-0.3 mm, terminal. Ovary 18-25 locular, inferior, the apex glabrous and forming a collar around the style; style 7-8 mm long, usually straight but sometimes slightly curving, distance from the anther to the stigma ca. -2 - 0 mm, stigma crateriform, consisting of 18-25 laterally compressed lobes, 6.5-8 mm wide. Berry 14-18 × 10-12 mm, purple. Seeds 0.5-1 mm long, narrowly ellipsoid, the testa smooth.

Distribution

(Fig. 87 ). Endemic to Costa Rica, 1300-3000 m elevation.

Conostegia macrantha can be recognized by its stout branches, stellate indument on abaxial leaf surface, and large flowers with crateriform, straight styles, and retuse petals. Flowers of this species have a good fragrance (i.e., Chavarría 817, Jiménez 626 -both at MO). This species is also reported from northern Panama by Schnell (1996) but I have not seen any Panamanian specimens. The few specimens from Panama that resemble Conostegia macrantha are glabrous, the reason why I did not include them in the distribution of this species presented here. Schnell (1996) noted that the species is especially common in the volcanoes surrounding the central valley of Costa Rica and is mostly restricted to that area. Specimens collected near Barva and Poas volcano for this study have the typical straight styles of Conostegia macrantha . Schnell (1996) noted some specimens from Vara Blanca showed evidence of introgression from Conostegia oerstediana in their smaller flowers.

Specimens examined.

COSTA RICA. Alajuela: Near Continental Divide, vicinity of Vara Blanca, Chrysler 5348 (NY); Alfaro Ruiz hills above laguna, Smith 10075 (NY) . Cartago: Volcán Turrialba on road between Lechería La Central and La Trinidad, Schnell 1077 (MO, NY); south slope of Turrialba Volcano above Santa Cruz, Williams 19677 (NY); near La Sierra, about 25 km south of Cartago , Cordillera de Talamanca , Williams et al. 28022 (NY) . Heredia: Sacramento, Finca Ingrid Steinvorth, Kriebel 5406 (INB, NY); near Río Las Vueltas N.E. of Volcán Barba, Lent 2644 (CR, NY) . San José: San Cristóbal Norte, Desamparados, Antonio 706 (CR, NY); Property of Hacienda Forestales above Cascajal , Lumer 1301 (NY); NE of Coronado, Chrysler 5348 (NY); Riviera de los Arcángeles, Escazú, Pittier 13053 (NY) .

Figures

Figure 86. Conostegia macrantha. A Leaf abaxial foliar surface B Inflorescence C Lateral view of flower at anthesis D Frontal view of flower at anthesis E Close up of the surface of the hypanthium F Longitudinal section of a hypanthium of a flower at anthesis with its parts removed G Petal H Stamen I Style J Stigma. Photos of specimen vouchered R. Kriebel 5406.

Figure 87. Distribution of Conostegia macrantha.