Molopanthera Turcz.

• Authority

  Delprete, Piero G. 1999. Rondeletieae (Rubiaceae). Part I. Fl. Neotrop. Monogr. 77: 1-226. (Published by NYBG Press)

• Family

  Rubiaceae

• Scientific Name

  Molopanthera Turcz.

• Type

  Type species. Molopanthera paniculata Turczaninow.

• Synonyms

  Forsteronia G.Mey., Molopanthera paniculata Turcz.

• Description

  Genus Description - Trees; bark longitudinally fissured, brown; sap wood pale yellow, very hard; heartwood light-brown. Stipules interpetiolar, free at base, adnate to petioles, persistent. Leaves elliptic to narrowly elliptic, acuminate at apex; not pellucid punctate; petioles slightly thickened at base; domatia absent. Inflorescences terminal, frondose, pyramidal, laxly paniculate, secondary branches subtended by leaf-like bracts, tertiary branchlets thyrsoid. Flowers zygomorphic (flower buds and stamens curved upward), protandrous, sessile to short-pedicellate, fragrant; hypanthium obovoid. Calyx extremely reduced, with minute deltoid lobes, persistent. Corolla rotate, curved upward, deeply lobed, with reflexed unequal lobes, glabrous throughout, white to cream-white; tube short-cylindrical; lobes (4-)5; aestivation imbricate. Stamens 5, alternate to petals, unequal (the lower ones longer than the upper ones), exserted; filaments attached near the base of the tube, slender, basally flattened, glabrous; anthers narrowly elliptic, dorsifixed near base, dehiscing by lateral slits. Pollen tricolporate, exine densely reticulate. Style exserted, elongating after anther dehiscence; style branches narrowly oblong, reflexed at maturity. Ovary 2-celled, obovoid, bilobed, with a globose placenta supported by a transverse stalk attached to the septum; ovules many per locule. Capsules thin-woody, strongly bilobed, the two sides subglobose; dehiscing loculicidally, disk septicidal dehiscence absent. Seeds with irregular outline, with a concentric deeply fringed wing.

• Discussion

  Molopanthera is a rare genus of trees endemic to the forests of eastern Brazil, easily recognizable by its minute curved flower buds (Figs. 4T, 85B), small bilobed-globose capsules, capitate placenta supported by a short stalk, seeds peltate to the placenta, umbilically attached, and concentric seed-wing with deeply fringed margins (Fig. 11B).

  Genera with zygomorphic flowers are rare in the Rubiaceae. In Molopanthera, zygomorphy is more noticeable in its minute flower buds, which are curved upward (Fig. 85B), than in its open flowers (Fig. 85C). Nevertheless, when magnified, it is possible to appreciate the unequal length of the filaments and corolla lobes (longer in the lower portion of the corolla). The filaments remain bent upward in two couples with the two adjacent anthers connected to each other by their pointed extensions at both ends, forming two cupshaped units (Fig. 85C), the fifth filament remaining free. This particular morphology is correlated with its peculiar pollination syndrome. The anthers in couples release pollen in a spherical mass, which is thrown onto the pollinator (i.e., small bees) by the single anther (pers, obs.)
  Turczaninow (1848) in describing M. paniculata as having leaves glabrous throughout. The generic name is derived from the Greek [Greek symbols] (molops = bruise or weal) and [Greek symbols] (anteros = anther), meaning bruised anthers, probably in allusion to the fact that they are often fused (in couples) during anthesis.
  Molopanthera has been treated as incertae sedis (Turczaninow, 1848), tentatively placed in the Cinchoneae (Hooker, 1873; Baillon, 1880; Schumann 1889,1891), transferred to the Condamineeae (sensu Hooker) by Andersson and Pearsson (1991), and included in the "genera associated with Portlandia" by Robbrecht (1993). Molopanthera is here treated as a monotypic genus with the two varieties recognized by Schumann (1889).