Friday, January 14, 2022

[Botany • 2021] Monstera gigas, M. titanum, et al. • Four New Species of Monstera (Araceae) from Panama, including One with the Largest Leaves and Another with the Largest Inflorescences in the Genus


Monstera titanum Croat, M.Cedeño & O.Ortiz 
Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz,

in Cedeño-Fonseca, Ortiz, Zuluaga, Grayum & Croat, 2021. 

Abstract 

Monstera bocatorensis Croat & M.Cedeño, Monstera donosoensis Croat, M.Cedeño & O.Ortiz, Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz, and Monstera titanum Croat, M.Cedeño & O.Ortiz are newly described from Panama, and illustrated from living material.

Keywords: Araceae, Central America, Monstera, Panama, Parque Internacional de La Amistad


Monstera bocatorensis Croat & M.Cedeño, sp. nov.

Diagnosis: Monstera bocatorensis is characterized by its smooth and glaucous stems, long, smooth petioles glaucous throughout and 46–90 cm long, short petiole sheaths that extend only to the middle or ¾ of its length, usually deeply pinnatifid (rarely entire) leafblades, never perforate, and smooth, light green or dark green peduncles, 27–45 cm long, entirely covered by the cataphylls.

Etymology: The species is named after Bocas del Toro Province, Panama, where all the known specimens have been collected.

Distribution and habitat: Monstera bocatorensis is endemic to Panama, where it is known only from the western slopes of the mountains east of Fortuna Dam below the Continental Divide in Bocas del Toro Province, from sea level to 1100 m, in the Tropical wet forest and Premontane wet forest life zones.


Monstera donosoensis Croat, M.Cedeño & O.Ortíz, sp. nov.

Diagnosis: Monstera donosoensis is characterized by its dark green petioles with a deciduous or slightly persistent sheath, entire, pinnatilobed, or scarcely pinnatifid leaf blades, with or without fenestrations, spathe yellowish or cream externally and white or creamy internally, and flowers with the style hexagonal, strongly conical, and distally cylindrical.

Etymology: The species is named after Donoso District, Colón Province, Panama, in which the type was collected.

Distribution and habitat: Monstera donosoensis is endemic to Panama, where it is known from Darién, Coclé, Colón, Veraguas, Panamá, Panamá Oeste provinces, and Guna Yala comarca, at elevations of 100–1600 m, in the Premontane rainforest life zone.


Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz.
 A. Adult plant. B. Adult leaf-blade. C. Petiole (with black arrow indicating slightly persistent sheath) and imma-ture infructescence (with white arrow indicating white stylar cap). D. Adult leaves (with white arrow indicating white-dotted geniculum and black arrow indicating subcordate base of blade).
Photos by Alejandro Zuluaga.

Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz.
Michael Mittermeier (left) with a leaf up to 3 m of length, and Marco Cedeño and Orlando Ortiz (right) with a leaf up to 2 m of length.
 Photos by Esteban Jiménez.
 
Monstera gigas Croat, Zuluaga, M.Cedeño & O.Ortiz, sp. nov. 

Diagnosis: Monstera gigas is characterized by petioles with white dots, a slightly persistent sheath, sometimes enor-mous leaf blades subcordate at the base, with entire margins, with or without fenestrations, and 24–65 pri-mary lateral veins per side, sunken adaxially, departing the midrib at 80–90° in the lower part of the blade and 55–75° toward the apex.

 Etymology: The epithet is a noun in apposition, from the ancient Greek word “gígas” meaning a giant, in reference to the exceedingly large size of its leaves, the largest recorded in the genus.

Distribution and habitat: Monstera gigas is endemic to Panama, where it is known only from the type locality in the region of the Fortuna Lake at 1200–1300 m, in the Premontane rain forest life zone.



Monstera titanum Croat, M.Cedeño & O.Ortiz.
A. Adult plant. B. Immature infructescence, with marcescent spathe. C. Adult leaf-blade (with arrow indicat-ing primary lateral veins departing the midrib at 75–95°). D. Adult leaf-blades (with arrow indicating subcordate base).
Photos by Marco Cedeño-Fonseca.

Monstera titanum Croat, M.Cedeño & O.Ortiz, sp. nov.

Diagnosis: Monstera titanum is characterized by its dark green stems with white dots, petioles 50–95 cm long, with the sheath slightly persistent, leaf blades subcordate at the base, with 20–40 primary lateral veins per side, departing the midrib at 75–95°, prominent collective veins, and compound fenestrations, with small fenestrations along the midrib or near the margins, and its inflorescence up to 95 cm in length.

Etymology: The species epithet, conveying enormous size, is from the greek ‘titanikos’ itself drawn from the Titans, the race of giant ancient Greek gods. It alludes to the huge size of the inflorescence, the largest known in the genus.

Distribution and habitat: Monstera titanum is endemic to Panama, where it is known from the type locality on Altos del Maria, Valle of Anton, and the border of Chiriquí and Bocas del Toro Provinces, at 1450–1480 m elevation in the Premontane rain forest life zone.


Marco Cedeño-Fonseca, Orlando O. Ortiz, Alejandro Zuluaga, Michael H. Grayum and Thomas B. Croat. 2021. Four New Species of Monstera (Araceae) from Panama, including One with the Largest Leaves and Another with the Largest Inflorescences in the Genus. Webbia: Journal of Plant Taxonomy and Geography76(2); 265-279. DOI: 10.36253/jopt-10807