6. Rhodostemonodaphne frontinensis

Rhodostemonodaphne frontinensis Madriñán, sp. nov.

Type. Colombia. Antioquia: Mun. Frontino, Murrí rd. 15 km W of Nutibara (Altos de Cuevas), 18 Oct 1987 (stam. fl), Brant & Martínez 1387 (holotype, HUA; isotypes, AAU, HBG, K, MO, NY).

Rhodostemonodaphnae laxae, R. cyclopi et Endlicheriae colombianae similis, a primaria foliis majoribus et staminibus verticillorum I et II latioribus, a secunda ramulis tomentosis, a tertiaria indumento nec adpreso differt.

Named after the Mun. of Frontino in the department of Antioquia, Colombia.

Description

Trees: branches basitonic, in axils of cataphylls; twigs angular, soon becoming terete, 4–5 mm diam.; epidermis brownish to black, barely visible due to indument cover; terminal bud plump, 7–9 X 4–6 mm; cataphylls caducous; indument pubescent, caducous after one flush, the hairs dense, up to 0.8 mm long, straight, erect, yellowish. Leaves: petioles robust, 1.5–2.6 cm X 2.4–3 mm, adaxially flattened; blades chartaceous, flat, broadly elliptic to obovate, 8–20 X 3–12 cm; base obtuse to rounded, minutely decurrent, 80–150°; apex obtuse to rounded, 80–120°, ultimately acuminate for up to 1.2 cm; margin flatmargin plane; primary vein above flat, below prominent; secondary veins 8–10 pairs, equidistant, brochidodromous, above flat, below raised, diverging at 50–60°, abruptly arching near margin (forked), chordal angle ca. 30°, lowest pair more obtuse than rest; tertiary veins above flat, below slightly raised, random-reticulate to scalariform; higher order veins above flat, below slightly raised; surface above olive-green to brown, below dark yellowish-brown; indument above puberulous, primary , the primary and secondary veins tomentose, caducous by next flush? (all leaves of previous flush fallen), below tomentose, the hairs dense, up to 1 mm long, straight to curved, erect, yellowish, denser on the veins, caducous after one flush? Staminate inflorescences: basitonic, erect?, peduncles 5–12 cm long, hypopodiathe hypopodia 1–4 cm X 1.4–2 mm, branch orders 5, second-order , the second-order branches 4–8, dispersed, lowest branch up to 3 cm long, all axes blackish, puberulous; bracts and bracteoles caducous (not seen). Staminate flowers: pedicels ca. 5.6 X 1.2 mm, the diameter gradually increasing apically; receptacle obconical, ca. 2.4 X 3.5 mm; tepals coriaceous, ovate, ca. 2.5 X 1.5 mm, at anthesis erect to spreading, black, adaxially patchy puberulous; stamens of whorls I and II sessile, anther , the antherssessile trapezoid, ca. 1.6 X 1.2 mm (whorl II slightly smaller), glabrous, locelli, the locelli 4 (lowerthe lower pair much larger than upperthe upper pair), apical, in a shallow arch, introrse, glands, the glands absent; whorl III columnar, ca. 1.4 X 0.8 mm, glabrous, locelli, the locelli 4, upperthe upper pair latrorse, lowerthe lower pair extrorse (upperthe upper almost introrse), glands, the glands fused, forming a continuous ring protruding between the outer whorls; whorl IV absent; all stamens yellowish-brown to black; pistillode filiform, ca. 1.2 X 0.4 mm, glabrous. Pistillate flowers and fruits unknown.

Field notes

Trees up to 6 m tall. Inflorescence axes yellowish-green; receptacle yellowish-green; tepals cream.

Distribution

Known only from the type found on the northern part of the Western Cordillera Occidental of the Colombian Andes, at 1850 m elev.  The type specimen was found growing at the margin of upper-montane forest.  Found flowering in October at the height of the rainy season.

Additional specimens examined

 

Discussion

This is a species that closely resembles Rh.Rhodostemonodaphne  cyclops from the cloud forests near Quito, Ecuador.  The indument on all plant parts, including the puberulous adaxial surface of the tepals, and leaf shape, size, consistency and venation of both species are very similar.  Nevertheless, in Rh.R. cyclops the indument on the twigs is shorter, the inflorescence axes are thicker, and the flowers have a more elongated, trumpet-shaped receptacle than in Rh.R. frontinensis.

Rhodostemonodaphne frontinensis is also similar to Rh.R. laxa and Rh.R. velutina, two closely related species also from the Andes of Colombia.  However, the leaves of these two species are narrow-elliptic as opposed to the wide-elliptic ones of Rh.R. frontinensis.  Furthermore, the flowers of both Rh.R. laxa and Rh.R. velutina have narrow anthers of whorls I & II as opposed to the wide ones of Rh.R. frontinensis.

In both vegetative and inflorescence characters, as well as gross floral structure, Rh.R. frontinensis is very similar to Endlicheria colombiana (Meissner) Mez, a species of upper-montane forest in Colombia, also found in the same general locality as Rh.R. frontinensis.  Nevertheless, E. colombiana has appressed, straight, ascending hairs, and flowers with 2-locellate anthers.
Contact | Updated 28.07.2005 | ©2005 Santiago Madriñán