Euplassa chimantensis Steyerm.

Plana, V. & Prance, G. (2004). A Synopsis of the South American Genus Euplassa (Proteaceae). Kew Bulletin, 59(1), 27-45. doi:10.2307/4111072

Type

Venezuela: Estado Bolivar: Torono-tepui: Chimanta Massif: south facing forested slopes above valley of South Caño, on summit, alt. 1955 - 2090 m, 23 Feb. 1955 (young fl.), Steyermark & Wurdack 1103 (holotype VEN; isotypes F!, NY).

Morphology General Habit

Tree

Morphology Leaves

Leaves rigid-coriaceous

Morphology Leaves Leaflets

Leaflets thickly coriaceous leaflets with revolute margins; leaflets are generally broad with retuse to emarginate apices

Morphology Leaves Leaf veins

Midvein and secondary veins are broad and extremely prominent beneath, and sunken on the upper surface of the leaflets

Morphology General Buds

Buds yellowish.

Distribution

Known only from type locality. Venezuela: Estado Bolívar.

Conservation

Rare.

Phenology

Young buds present in February. Probably similar phenology to other northern Venezuelan species, which tend to flower in February to March and set fruit from April.

Note

Somewhat similar to E. duquei in the robust nature of the leaves, inflorescences and flowers. Unfortunately, this species is known only from type material, which is either sterile or in young bud, and therefore lacks defining information such as flower shape and length, curvature of the tepals, and fusion of the hypogynous nectaries in mature flowers. The young buds do express these characteristics but how these may change with maturity is unknown. The immature hypogynous glands of the young buds are entirely fused to form a quadrangular structure and the very young ovary has a few stiff rufous hairs scattered on its surface. If these characters remained unchanged to maturity then E. chimantensis would be most closely affiliated to other northern South American species such as E. glaziovii, to which it is also closest geographically, E. pinnata, and E. madeirae. It closely resembles E. glaziovii because the latter can also have leathery leaflets which are frequently retuse and sometimes emarginate at the apex. Euplassa chimantensis, however, is distinguished by its leaflets which are thickly coriaceous, probably the thickest in the entire genus, and when alive are probably rigid and brittle. The most characteristic and diagnostic character of this species is the venation. The midvein and secondaries are extremely prominent, the diameter of the midvein is 1.5 to 2 mm in diameter, while in other species, like E. glaziovii, it reaches a maximum of about 1 mm. The sunken secondaries on the upper surface of the leaflets, are also diagnostic and a rare feature in other northwestern species.

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: threatened. Confidence: confident