Wednesday, October 10, 2018

[Botany • 2018] Blakea echinata (Melastomataceae: Blakeeae) • A New Species from the Caribbean Rainforest of Panama

Blakea echinata  Almeda & Penneys

in Almeda & Penneys, 2018. 

Blakea echinata from the lowland Caribbean rainforest of Panama is described, illustrated, mapped, and compared with superficially similar species. It is readily distinguished by its elongate internodes; indumentum of spreading smooth (sometimes gland-tipped) trichomes on distal branchlets, leaves, floral bracts, and calyx lobes intermixed with laterally compressed and somewhat roughened conic to clavate or ± triangular trichomes on distal branchlets, floral peduncles, and abaxial surfaces of floral bracts; rhombic reflexed basally clawed petals; yellow-orange unappendaged anthers; and ovary apex that is elaborated into a distally glandular-laciniate collar 5–6 mm long that envelops the style base. A conservation assessment of Critically Endangered is recommended for this species based on IUCN Red List Categories and Criteria.

Keywords: Blakeeae, conservation, epiphyte, neotropics, new species, Panama, Eudicots

Figure 1. Blakea echinata.
A. Habit. B. Representative leaf (abaxial surface) C. Distal portion of peduncle and outer floral bracts. D. Inner floral bracts. E. Hypanthium and calyx lobes. F. Longitudinal section of flower showing ovary, collar, and calyx lobes. G. Flower at anthesis. H. Stamens, ventral view (left) and profile view (right). I. Petal (adaxial surface).
All drawn from De Gracia 765.

Figure 2. Images of Blakea echinata.
A. Flower. B. Habit. C. Flowers and subtending leaves. D. Hypanthia and subtending floral bracts. E. Flower showing reflexed petals (right) and flower at post anthesis (left). F. Young fruiting hypanthia with spreading calyx lobes and subtending floral bracts.
Image credits: A–F (De Gracia 763) by J. E. De Gracia.

Blakea echinata Almeda & Penneys, sp. nov. 

Diagnosis: Distinguished by its epiphytic habit with elongate internodes, distal branchlets moderately to sparingly covered with a mixture of smooth (sometimes gland-tipped) spreading trichomes (1–3 mm long) that are white when fresh but dull yellow-brown when dry, and early deciduous laterally compressed and somewhat roughened conic to clavate or ± triangular trichomes up to 0.5 mm long, inner and outer floral bracts that are connate basally for 2–6 mm to form a tight collar enveloping the hypanthium, calyx tube 2–3 mm long, oblong-obovate calyx lobes, rhombic commonly reflexed petals with a basal claw, yellow-orange unappendaged anthers, and ovary apex elaborated into a distally glandular-laciniate collar 5–6 mm long that envelops the style base.

Figure 3. Geographic distribution of Blakea echinata.

Habitat and distribution:— This species has been collected in mature secondary rainforest in the Caribbean lowlands of Panama at 100–150 m elevation where it is known from a small area in the Donoso District of Colón province (Figure 3). 

 Etymology:—The epithet for this species, echinata, highlights the copious and conspicuous indumentum of stiff smooth and/or gland-tipped spreading trichomes on leaves, petioles, floral bracts, and calyx lobes.

Frank Almeda and Darin Penneys. 2018. Blakea echinata (Melastomataceae: Blakeeae): A New Species from the Caribbean Rainforest of Panama.  Phytotaxa. 372(1); 104–110. DOI:  10.11646/phytotaxa.372.1.9

Resumen: Se describe e ilustra Blakea echinata de la selva baja del Caribe de Panamá, se presenta un mapa y se la compara con especies superficialmente similares. Se distingue fácilmente por sus entrenudos alargados, indumento de tricomas suaves extendidos (a veces con punta glandular) en las ramitas distales, hojas, brácteas florales y lóbulos del cáliz entremezclados con tricomas cónicos a clavados o triangulares lateralmente comprimidos y algo rugosos en ramitas distales, pedúnculos florales y superficies abaxiales de las brácteas florales; pétalos rómbicos basalmente con una reflexa, anteras de color amarillonaranja sin apéndice y el ápice de ovario que se elabora en un collar distalmente glandular-laciniado de 5–6 mm de largo que envuelve la base de estilo. Se recomienda una categoría de conservación de En Peligro Crítico para esta especie en base a las Categorías y Criterios de la Lista Roja de la UICN.