Macrolobium machaerioides Killip & J.F.Macbr.

Trujillo-López, Ana María & Londoño-Echeverri, Yeison, 2023, Novelties in Macrolobium (Detarioideae, Fabaceae) for Northern South America: Two new species and new chorological records from Colombia and Ecuador, Phytotaxa 599 (3), pp. 155-170 : 166-168

Macrolobium machaerioides Killip & J.F.Macbr.

Type:— PERU. Loreto: Mishuyacu, near Iquitos, forest, 100 m, October-November 1929 (fl), G. Klug 547 (holotype: US-1455546 [digital image!], isotypes: F-613442 [digital image!], F-1116544 frag. [digital image!], NY barcode-4473 [digital image!]) .

This species is described from Peruvian Amazon in Macbride (1943). In the protologue and in the revision of Cowan (1953), the fruits morphology was unknown. Subsequently, R. S. Cowan determined a fruiting specimen in 1985, recorded from Huánuco, Perú, by J. Schunke in 1966 ( J. Schunke 1058 [ NY!]). This is the first known collection with fruits for the species, but its morphology stills unpublished heretofore.

Macrolobium machaerioides is easily recognizable by its leaflets auriculate basally at the acroscopic half and its leaflet apex strongly emarginate ( Fig. 6 ). It has been recently found in the Amazon region in the departments of Amazonas and Putumayo in Colombia, and in province of Napo in Ecuador ( Fig. 3 ).

Mancera (2016) report to Macrolobium machaerioides from the Inter-Andean Valleys of the department of Antioquia, Colombia, however, this record was based on specimens ( A. Cogollo et al. 223 [ JAUM, 2 sheets; MO]) that belong to new species described here, M. longistipitatum .

Emended fruit description:— Fruits 4.8–6.9 × 2.9–4.5 cm (including the stipe), 0.3–0.6 cm long stipitate, obovate, obtuse and rounded basally, obtuse and rounded to truncate apically, sparsely villose marginally, otherwise glabrous, indehiscent, inflated in the seminal cavity. Seeds 1–2, not examined (few fruits available).

Additional specimens examined:— COLOMBIA. Amazonas. Mun. Leticia: Parque Nacional Natural Amacayacu, Sector sureste del parque, parcela permanente “ U ” En bosque de tierra firme sobre suelos arcillosos, 80– 110 m, 3°43ʹ10ʹʹS, 70°18ʹ25.8ʹʹW, 9 February 2005 (st), A. Prieto et al. 2983 (FMB-81392!); Parque Nacional Natural Amacayacu, Alrededores de la quebrada Agua Pudre en bosque de terra firme, Parcela E, No. 10, 120 m, 3°42ʹ00ʹʹS, 70°15ʹ00ʹʹW, 21 March 1992 (st), A. Rudas et al. 3408 (HUA-114023!, FMB-28265!, MO [n.v.]); ibid., Parcela E, No. 11, 22 March 1992 (fr), A. Rudas et al. 3471 (HUA-114057!); Parque Nacional Natural Amacayacu, 100 m, 3°47ʹ00ʹʹS, 70°15ʹ00ʹʹW, 1991 (st), A. Rudas 4100 (FMB-39389!, MO [n.v.]); Parque Nacional Natural Amacayacu, Alrededores de la quebrada Agua Pudre en bosque de terra firme, Transecto U11 - U 12, 120 m, 3°42ʹ00ʹʹS, 70°15ʹ00ʹʹW, 30 March 1992 (st), A. Rudas et al. 4131 (HUA-113712!). Putumayo. Mun. Puerto Asís: Vereda Canacas, 230 m, 0°33ʹ19.95ʹʹN, 76°17ʹ54.19ʹʹW, 30 May 2017 (st), P. Díaz 22 (TOLI-18422!) . ECUADOR. Napo: Añangu, NW corner of the “Parque Nacional Yasuní”, Primary terra firme forest on permanent study plot S of SEF point 51, on the highest plateau in the area, 355–365 m, 00°33ʹ00ʹʹS, 76°22ʹ00ʹʹW, 1–15 February 1986 (fr), J. Korning & K. Thomsen 47735 (US-3281752 [digital image!]) . PERU. Huanuco: Carretera a Monzón in tall forest, 833 m, 11 February 1966 (fr), J. Schunke 1058 ( NY barcode-3196918 [digital image!]) .

Figures

FIGURE 3. Geographical distribution of Macrolobium ceriferum and M. longistipitatum, and of M. machaerioides from Colombia and Ecuador (type locality georeferenced, indicated with *).

FIGURE 6. Specimen of Macrolobium machaerioides, from A. Rudas et al. 3471 (HUA).