Euplassa inaequalis (Pohl) Engl.

  • Authority

    Prance, Ghillean T., et al. 2007. Proteaceae. Fl. Neotrop. Monogr. 100: 1-218. (Published by NYBG Press)

  • Family

    Proteaceae

  • Scientific Name

    Euplassa inaequalis (Pohl) Engl.

  • Type

    Type. Brazil. Goiás: circa Array al N. Senh. do Carmo capitaniae, Pohl 2303 (holotype, M, photo F, GH).

  • Synonyms

    Adenostephanus inaequalis (Pohl) Endl., Euplassa goyazensis K.Schum., Adenostephanus emarginata Glaz., Euplassa warmingii Sleumer

  • Description

    Species Description - Tree, to 20 m, very rarely a shrub. Young stems reddish-brown, glabrescent to ferruginous-tomentose, the indumentum commonly lost with maturity, the striations narrow, multiple, not visible in very young stems; older branches dark brown to black, glabrous to tomentose, striations conspicuous, unfissured or with numerous shallow fissures. Lenticels few, minute and inconspicuous to large and conspicuous, <0.5-3 mm long, suborbicular to narrowly elliptic, prominent or not, light brown, rarely producing fissures or only very small ones. Petiole 3.8-18.8 cm long, terete, 2-3.5 mm diam, at the base, sparsely appressed-puberulous (seen only under magnification). Leaf rhachis 2.4-21.5 cm long, the terminal appendix commonly 2-5 mm long and 0.5-1.5 mm broad, rarely producing a small terminal leaflet; leaflets subsessile to short-petiolate, the petiolules to 8 mm long, 2.5-3 mm at the base. Leaflets 2-4(-5) pairs, opposite to subopposite, overlapping or not, drying light green to brown to black, subcoriaceous to coriaceous, matte to shiny, glabrous to glabrescent with venation ferruginous-tomentose above, glabrous to ferruginous-pilose beneath when the latter, the midvein and secondary veins densely ferruginous-tomentose, symmetrical to asymmetrical, the shape very variable, narrowly to broadly obovate, elliptic-ovate to oblong-ovate; basal pair elliptic to oval to suborbicular, 4.5-13.2 × 3-10.4 cm; other leaflets 7.9-25.9 × 3.6-11.2 cm; base generally strongly oblique, acute to attenuate; apex acute to rounded, sometimes broadly mucronate to attenuate, rarely retuse or emarginate, minutely mucronulate in some leaves due to extension of midrib; margin various, entire to remotely serrate, undulate or not, the leaflets frequently complicate and folded over in dry specimens; venation cladodromous to weakly brochidodromous, with 4-7 lateral veins, the midvein prominent throughout, reaching the apex, the secondaries prominent, the higher order venation conspicuous on both surfaces, less frequently obscure above. Inflorescence moderately to very congested, occasionally branched or with two inflorescences per leaf axil, axillary, rarely lateral, 2.7-3.5 cm diam.; peduncle 1.7-3.5 cm long, 1.25-1.5 mm diam, immediately below inflorescence; floral rhachis 5-14.5 cm long, ferruginous appressed-puberulent to sparsely appressed-pubescent; bracteoles strongly heteromorphic, the basal ones 3-5 mm long, frequently absent, usually broken off, linear, velutinous, the superior ones 1-1.5 mm long, triangular, ferruginous-pubescent, frequently contrasting against the sparsely indumented rhachis, the inferior bracteoles frequently reflexed; flower-pair peduncle absent to 4 mm long, appressed , ferruginous-puberulent; pedicels 1.5-4 mm long. Buds 2-2.5 mm broad at apex, 0.5-0.75 mm broad at midlength, essentially erect, sparsely ferruginous-puberulent. Rowers 6-10 mm long, all perianth segments recurving at anthesis; tepals 1-1.3 cm long, 0.25-0.75 mm across at midlength, keeled. Anthers subsessile, ca. 1.5 mm long. Hypogynous nectaries fused into a quadrangle, usually 1 mm high and 1 mm across, frequently dwarfing the ovary, the abaxial gap not present. Ovary 1-1.5 mm long, generally narrow, slightly wider than the style, sometimes pyriform, glabrous, very rarely with some very sparse pubescence on the lower half. Infructescence 8.4-9.2 cm long; fruit pedicels 56 mm long, 1-1.25 mm thick. Fruit (immature) subglobose to broadly obovoid, occasionally slightly compressed, 1.2-1.6 × 0.8-1.2 cm, drying dark brown, minutely pustulate, rough to the touch. Exterior mesocarp 0.5 mm thick, black; interior mesocarp 1-1.25 mm thick, porous, light in color.

  • Discussion

    Euplassa inaequalis is a highly plastic species showing a broad range of variation, which is, however, mostly limited to leaflet size and ovary and leaflet pubescence. On the whole, there appears to be little correlation between these characters and geographic or ecological distribution, although a weak correlation does exist concerning degrees of pubescence. The more pubescent specimens-which possess leaflets that are evenly pubescent beneath and often have partially hairy ovaries-are almost strictly confined to cerrado and cerradão, with occasional occurences in gallery forest. This form is extremely rare in forests. On the other hand, the more glabrous forms are more common in forests, but may sometimes also be found in cerrado. This species is unique within the genus in having a very wide distribution and adaptability to different habitats and different altitudes.

    Euplassa inaequalis seems to share characters with a number of other species and therefore frequently seems closely associated with species that have little in common with each other. It shows strong affinities with the northwest South American species of Euplassa such as E. pinnata, E. glaziovii, E. chimantensis, E. madeirae, and E. occidentalis, especially with the last two. The glabrescent or more common form of E. inaequalis shares glabrous to glabrescent leaves, puberulent inflorescences, and fused hypogynous glands with these five species. The principle differences are in the ovary, which is generally glabrous in E. inaequalis (those specimens with a partly pubescent ovary are very rare and usually correlated with a more densely indumented leaf) and entirely rufous-puberulent in E. pinnata, E. glaziovii, E. chimantensis, and E. madeirae. Euplassa occidentalis has a partially pubescent ovary, the hairs being either white and closely appressed or ferruginous. The bud and rhachis indumentum tends to be yellowish or light ferruginous and always closely appressed, which is noticeably different from the ferruginous spreading hairs of E. inaequalis. There are also differences in leaf shape and venation, but these may often be indistinct, especially to the untrained eye. Therefore, the most important characters to differentiate E. inaequalis from other similar species are geographical distribution (e.g., E. occidentalis only occurs in the Ecuadorian Andes, E. madeirae in Amazonian Brazil and Colombia) and the indumentum of the lower surface of the leaves. The leaflets of E. inaequalis are usually glabrescent beneath with a few ferruginous spreading hairs (more densely pubescent in some specimens); in contrast, E. glaziovii, E. occidentalis, and E. chimantensis are very distinctly sparse white-puberulent beneath, the hairs short and closely appressed. However, in a few collections E. inaequalis may also have appressed puberulence on the leaflet undersurface, and in these cases it may be impossible to identify the specimen if sterile. The more densely pubescent specimens of E. inaequalis also show close affinities with E. legalis var. legalis. In sterile specimens, it may be difficult to impossible to differentiate E. legalis var. legalis from the pubescent forms of E. inaequalis. When in flower, the the latter generally has densely tomentose inflorescences (including rhachis, buds, and pedicels), while those of E. inae- qualis are puberulent. Also, E. legalis var. legalis is geographically restricted to Rio de Janeiro, while E. inaequalis may be found from central Peru and northern Pará and Maranhão to Rio Grande do Sul in SE Brazil. Forms in which the leaflet margins are serrate are rare, but do ocurr. If sterile, these specimens may be impossible to tell apart from E. hoehnei and E. incana. The leaflets of E. incana are usually sparsely pubescent beneath, while all of the serrate margined forms of E. inaequalis examined are glabrous, which can aid in identification. The leaflets of E. inaequalis can look very similar to those of E. hoehnei, and it is only possible to successfully differentiate between them when they are in flower, when the contrast between the distinct hypogynous nectaries of E. hoehnei and the fused nectaries of E. inaequalis is evident.

    Euplassa warmingii has been included in Euplassa inaequalis due to strong similarities in the flower, such as the glabrous ovary, ovary size with respect to the hypogynous structure, and the style (in E. inaequalis the ovary is commonly pyriform, not much broader than the style, and dwarfed by the nectary). The leaflets of the specimen of E. warmingii are somewhat smaller than the average leaflet size in the species but do agree with the lower measurements in the leaflet size range of E. inaequalis. The bud of E. warmingii is appressed-puberulent, as in E. inaequalis, and the bracteoles are distinct by being tomentose and contrasting with the puberulent rhachis and pedicel indumentum. The specimen of E. warmingii was collected in the Serra do Cipó and may show subtle differences with other specimens of E. inaequalis because it is material taken from a geographical border. The similarities between E. warmingii and E. inaequalis overrule any differences. This, in addition to the problem of the species concept of E. warmingii being based on a single specimen (holotype Lund 416), makes its species rank doubtful, and more likely to be a specimen of E. inaequalis.

    This species has been recorded as being visited by hummingbirds (Harley et al. 10072), which is unusual among the small-flowered genera of the Proteaceae in the neotropics. Pollination probably takes place by bees and moths, as in other neotropical Proteaceae with similar flower size; however, hummingbirds may visit flowers for the nectar without playing a role in pollination.

    The local name of this species hints at its form of seed dispersal. The smaller neotropical bats are large enough to carry the fruits of this species, which measure to 2 cm, and the fruits of most species of Euplassa. The local name fruto de morcego, or "bat fruit," is a common name used for other species in different families that are dispersed by bats, such as some fruits in the genus Andira (Fabaceae).

    Distribution and Ecology: Mainly a Brazilian species from the cerrados of Goiás and Mato Grosso, but also found in the states of Amazonas and Para, Bahia, Minas Gerais, Pernambuco, and Piauí. Occurring throughout a wide range of altitudes from 100-1200 m, with the lower altitudes occurring in Amazonia. It is commonly found in cerrado and associated habitats such as gallery forest and cerradão, but may also occur in wetter habitats like várzea forests in the Serra do Roncador in Mato Grosso, where it is common in cerradão and adjacent marshland (in Luciara), or on the margin of swampy gallery forests. The collections from Amazonia are from small patches of cerrado, as in Humaitá, or from terra firme forest. It has also been collected twice in the Jenaro Herrera Research Center in Loreto, Peru, where it has been found in humid forest at about 120 m elev.

    Euplassa inaequalis is identifiable by a combination of characters that include: an overall glabrous or glabrescent habit (except in some specimens, especially from cerrado, where the leaflets are pubescent beneath); fused hypogynous glands surrounding and extending to the middle of a narrow, glabrous (except very rarely partly hairy), generally pyriform ovary, not much broader than the style (and commonly square in cross section); and ferruginous appressed-puberulent indumentum covering the inflorescence. This species is so variable that some characters may overlap with those of other species. This species may be confused with Euplassa madeirae, E. occidentalis, E. venezuelana, E. pinnata, and E. legalis.

    Bark smooth, silvery; slash, bark red-brown; wood straw-colored. Flowers cream-colored, yellowish-green, to orange, sometimes turning pinkish with age; gynoecium bright green. Immature fruit green.

    Phenology. Found flowering almost throughout the year, mainly from Jun-Dec; fruiting in Jun and Oct. Sterile specimens collected in Jan, Sep, and Oct.

  • Common Names

    Fruta de morcego, mijo de guara, catuçanhem

  • Distribution

    Amazonas Brazil South America| Pará Brazil South America| Distrito Federal Brazil South America| Goiás Brazil South America| Mato Grosso Brazil South America| Bahia Brazil South America| Piauí Brazil South America| Minas Gerais Brazil South America| Loreto Peru South America|