Euplassa

  • Authority

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

  • Family

    Proteaceae

  • Scientific Name

    Euplassa

  • Type

    Type. Euplassa meridionalis Salisbury [= Euplassa pinnata (Lamarck) I. M. Johnston].

  • Synonyms

    Euplassa meridionalis Salisb., Dicneckeria, Adenostephanus, Didymanthus Endl., Euplassa pinnata (Lam.) I.M.Johnst., Adenostephanus inaequalis (Pohl) Endl., Didymanthus sellowii Klotzsch

  • Description

    Genus Description - Trees, less frequently shrubs. Young twigs pubescent, the indumentum lost with maturity. Older branches glabrous or with sparse indumentum, strongly fissured to unfissured, generally lenticellate. Indumentum frequently of glandular hairs. Leaves spirally arranged, paripinnate, the rhachis frequently ending in a terminal appendix extending to 2 cm beyond the terminal leaflet pair, rarely forming a terminal leaflet. Leaflets: 2-10 pairs, opposite to strongly subopposite, subsessile to long-petiolate, the shape various, the basal pair consistently smaller than the rest; margin entire to remotely serrate. Inflorescence generally unbranched, pseudoracemose, axillary or rarely terminal, solitary, occasionally with two inflorescences per leaf axil. Flowers in pairs, each pair supported by a peduncle of variable length that is frequently altogether absent; flowers sessile or pedicellate, weakly zygomorphic, each pair subtended by a small common bract, tepals four, all recurving at anthesis or one (the innermost) remaining erect; stamens epitepalous, the anthers ovate, subsessile, housed in the concave distal end of the tepals. Hypogynous nectaries four, fleshy, distinct, lobed or fused to form a quadrangular structure (or nectary disc). Ovary subsessile, glabrous to densely pubescent, with two pendulous, orthotropous ovules. Style curved; stigma latero-apical. Fruit a nut or rarely a drupe, 1- to 2-seeded, subglobose to ovoid; outer mesocarp thin and coriaceous or thick and fleshy; inner mesocarp thin and woody or very thick and sclerous; seeds fleshy, more or less compressed, not winged.

  • Discussion

    Although the preferred habitat is premontane forest and savanna, species of Euplassa may be found in gallery forest, cerradão, cloud forest, terra firme, or várzea. The majority of species in this genus tend to have very localized distributions, with unique populations only found in a few square kilometers. A small number of species are very widespread, found from sea level to 2000 m alt. and inhabiting a wide range of habitats.

    Most species in this genus can be identified by the combination of morphological characters of the gynoecium and flower-pair axis. Figure 14 shows individual flowers stripped of their perianth, revealing the detail of their ovary, hypogynous nectaries, pedicels, and common peduncles.

    Distribution and Ecology: Twenty species, endemic to tropical South America, ranging from its northernmost range in the state of Bolivar in Venezuela and central Colombia, to southeastern Brazil and Bolivia. They are found throughout the entire Andes to Bolivia, and are present in small numbers in the Amazon basin, northeastern Brazil, and French Guiana, corresponding to an approximate latitudinal distribution from 6° N to 30° S. The center of distribution is in southeastern Brazil from Minas Gerais to Parana, where about half the species occur. This genus is commonly found following mountain systems at altitudes between 900 and 2500 m. Some species may be present at lower altitudes, and although less common, this is the case for some species found in Amazonia and for the very widespread species E. inaequalis, which occupies a wide range of habitats. Distribution of species of Euplassa by country. BOLIVIA. Possibly a new species of Euplassa, undescribed (see section Undetermined Species, on p. 74). BRAZIL. Amapá: E. pinnata; Amazonas: E. inaequalis, E. madeirae; Bahia: E. bahiensis, E. inaequalis; Goiás: E. inaequalis; Maranhão: E. pinnata; Mato Grosso: E. inaequalis; Minas Gerais: E. inaequalis, E. incana, E. itatiaiae, E. organensis subsp, laxiflora, E. rufa, E. semicostata; Pará: E. inaequalis, E pinnata; Paraná: E. cantareirae; Pernambuco: E. inaequalis; Piauí: E. inaequalis; Rio de Janeiro: E. legalis var. legalis, E. legalis var. villanovae, E. organensis subsp. organensis, E. taubertiana, E. rufa; São Paulo: E. cantareirae, E. hoehnei, E. itatiaiae; Santa Catarina: E. cantareirae, E. nebularis; Rio Grande do Sul: E. nebularis. COLOMBIA. E. duquei, E. madeirae, E. saxicola. Ecuador. E. occidentalis. FRENCH GUIANA. E. pinnata. PERU. E. inaequalis, E. isernii. VENEZUELA. E. chimantensis, E. glaziovii.

  • Distribution

    Bolívar Venezuela South America| Venezuela South America| Colombia South America| Bolivia South America| Brazil South America| French Guiana South America| Minas Gerais Brazil South America| Paraná Brazil South America| Amapá Brazil South America| Goiás Brazil South America| Mato Grosso Brazil South America| Pará Brazil South America| Pernambuco Brazil South America| Maranhão Brazil South America| Paraná Brazil South America| Piauí Brazil South America| Rio de Janeiro Brazil South America| São Paulo Brazil South America| Santa Catarina Brazil South America| Rio Grande do Sul Brazil South America| Ecuador South America| Peru South America|