Macropharynx stenantha (Woodson) J.F. Morales & M.E. Endress, 2024

Morales, J. Francisco & Endress, Mary E., 2024, A synopsis of Macropharynx (Apocynaceae) in Colombia, with comments on floral characters, and a new combination, Phytotaxa 677 (2), pp. 173-180 : 177-178

Macropharynx stenantha (Woodson) J.F. Morales & M.E. Endress , comb. nov. Figs. 2G–H , 3A–B .

Basionym: Temnadenia stenantha Woodson (1934: 613) . Type:— Colombia. Boyacá: on edge of high forest, region of Mt. Chapon , 7000 ft, 17 June 1932 (fl), A. Lawrence 241 ( NY [lost in the mail on loan to VEN in 1978]) ; Boyaca: municipio La Victoria, monte El Chapón, abajo del cementerio antiguo, 26 July 1984 (fl), C. Orozco, A. Sanabria & D. Sánchez 1255 (neotype, designated here, COL! [ COL000202900 ]) .

Distribution: — Endemic to Colombia, restricted to the Oriental Cordillera, at (1200–) 1800–2080 m.

Observations:— Woodson (1934) described this species based on a single specimen collected by A. Lawrence in Boyaca, Colombia. Woodson cited that a photograph and analytical drawings were available at MO. However, we did not succeed locating these materials after several attempts. The circumscription of Temnadenia Miers (1878: 207) has been confusing since Miers described the genus. Woodson (1936) reduced the genus to four species, followed by Morales (2005c). Based on the results of a phylogenetic study of nuclear and plastid data, Morales et al. (2017a) reduced Temnadenia to two species and commented on the dubious position of T. stenantha and T. meyeri ( Ezcurra 1981: 241) . Endress et al. (2019) accepted three species only, excluding T. meyeri .

For many years, T. stenantha was known only from the type, which was lost in the mail in 1978 in a loan sent from New York (NY) to Venezuela (VEN). Although Woodson mentioned that a photograph and analytical drawing were at MO, such material has never been found. While reviewing material for the Flora of Colombia, two gatherings were found at the National Herbarium of Colombia (COL), one collected in the same type locality (Mt. Chapon). Both specimens have the rusty, dense, and minute brown indument (sometimes ferrugineous) typical of Macropharynx ( Fig. 3A–B ) and their morphological features match the description of T. stenantha . The corolla has the twisted tube reported for some species ( Fig. 3B ) ( Endress et al. 2019). Ronald J. Abarca (†) visited the Mt. Chapon area in 2022 and found plants with old fruits on a tree. The typical rusty indument was observed on new growth and old fruits ( Fig. 2H ). Due to the lack of collecting permits, he only photographed the plants. Based on the minute rusty indument, solitary calycine colleters, Included stamens, twisted corolla tube, anthers with slender basal appendages, five nectaries, fusiform stylehead, and fruits with rostrate seeds, T. stenantha is transferred to Macropharynx . Due to the loss of all the original material, a neotype is selected, choosing the gathering from the same type locality.

Representative specimens examined:— COLOMBIA. Santander: Gámbita, Vereda el Palmar, 12 May 1982 (fl, fr), G. Lozano 3775 (COL, CR).

Figures

FIGURE 2. Macropharynx species (photographs by J.F. Morales, except G–H [R.J. Abarca]. A–B. M. colombiana. C–D. M. isthmica. E–F. M. renteriae. G–H. M. stenantha. I. M. spectabilis.

FIGURE 3. Macropharynx stenantha (C. Orozco, A. Sanabria & D. Sánchez 1255, COL). A. Inflorescence. B. Twisted corolla tube (marked by an arrow).