Monographs Details: Rhodostemonodaphne tumucumaquensis Madriñán
Description:Latin Diagnosis - Rhodostemonodaphne leptocladae sine dubio proxima, sed foliis majoribus bullatis, petiolis brevioribus, necnon perianthiis et androeciis circumscissilibus statim diagnoscenda.
Species Description - Trees: branches basitonic?, in axils of cataphylls; twigs terete, ca. 2 mm diam.; epidermis brownish; terminal bud slender, ca. 3 x 2 mm; cataphylls caducous; indument pubescent, persisting for at least two flushes, the hairs dense, to 0.5 mm long, straight, erect, yellowish. Leaves: petioles pulvinate, 0.5-0.8 cm x 1.5-2.5 mm, terete; blades thinly chartaceous, flat to bullate, broadly elliptic, 7-15 X 3-7 cm; base acute to obtuse, 70-100°; apex obtuse to acute, 70100°, ultimately acuminate for up to 1.5 cm; margin plane; primary vein above and below raised; secondary veins 6-8 pairs, equidistant, brochidodromous, above and below raised, diverging at 55-65°, evenly arching, chordal angle ca. 30°, the angle uniform along blade length; tertiary veins above impressed, below raised, random-reticulate; higher-order veins above inconspicuous, below slightly raised; surface above dull dark green, below shiny light green; indument above absent, the primary vein tomentose, below minutely puberulous, the hairs isolated, to 0.2 mm long, straight, erect, yellowish, denser on the veins, caducous after one flush. Staminate inflorescences: basitonic, pendulous, peduncles to 5 cm long, the hypopodia ca. 3 cm x ca. 0.4 mm, branch orders 3, the second-order branches ca. 5, dispersed, lowest branch to 0.5 cm long, color and indument of all axes as on twigs; bracts and bracteoles caducous (not seen). Staminate flowers: pedicels ca. 2.4 X 0.6 mm, the diameter even throughout; receptacle flat, ca. 0.8 x 2 mm; tepals membranaceous, elliptic, ca. 2.5 x 1.2 mm, at anthesis spreading, reddish, somewhat translucent, adaxially glabrous; stamens of whorls I and II spathulate, the anthers reniform, ca. 0.8 X 0.6 mm, glabrous, the locelli 4, apical, in a strong arch, introrse, the glands absent; whorl III columnar, ca. 1.2 X 0.8 mm, glabrous, the locelli 4, the upper pair latrorse, the lower pair extrorse, the glands fused, forming a continuous ring; whorl IV absent; all stamens yellowish; pistillode absent. Pistillate flowers: pistil ca. 2.5 X 1.5 mm; ovary globose, ca. 1.5 mm long, glabrous. Fruits unknown.
Discussion:Field notes. Shrubs to 3 m tall and 3 cm diam. Tepals pink to red.Etymology. Named after the Tumucumaque (Tumuc-Humac in French Guiana) mountain range on the border between the Brazilian states of Amapá and Pará and Suriname and French Guiana.Rhodostemonodaphne tumucumaquensis has bright-green-drying, undulate to somewhat búllate leaves. The four specimens cited here were originally included in the description of R. leptoclada Madriñán. Unlike R. leptoclada, which has green flowers, the flowers of R. tumucumaquensis are red. As originally described and illustrated the pistillate individuals of R. tumucumaquensis have their tepals and stamens dehiscing in a ring after anthesis, while in R. leptoclada they are not. The collection from Mt. St. Marcel (initially though of as intermediate between the two above mentioned species) has flower buds at a very early stage of development; it has reddish tomentose twigs and leaves drying darker than R. leptoclada, and it very likely belongs to R. tumucumaquensis.
Distribution:French Guiana South America
| Brazil South America
| Amapá Brazil South America