Duckesia liesneri (Cuatrec.) K.Wurdack & C.E.Zartman, 2019

Wurdack, Kenneth J. & Zartman, Charles E., 2019, Insights on the systematics and morphology of Humiriaceae (Malpighiales): androecial and extrafloral nectary variation, two new combinations, and a new Sacoglottis from Guyana, PhytoKeys 124, pp. 87-121 : 96

Duckesia liesneri (Cuatrec.) K.Wurdack & C.E.Zartman comb. nov.

Humiriastrum liesneri Cuatrec., Phytologia 71: 165. 1991. Type: VENEZUELA. Amazonas, Depto. Rio Negro: Cerro Aracamuni, summit, Proa camp, 1400 m, 28 Oct 1987, R. Liesner & G. Carnevali 22589 (holotype: US-3111383; isotypes: MO-3641994, NY-00329209, US-3118837, VEN-277523).

Notes.

When Cuatrecasas (1991) originally described Humiriastrum liesneri , he expressed uncertainty about its anther structure and relationships due to reliance on young buds for floral details. A second collection (Venezuela. Amazonas, Sierra de Unturán, 1150 m, 3 Feb 1989, Henderson 933, US), correctly annotated by Cuatrecasas as H. liesneri in 1994, is in flower but did not cause any classification changes for the subsequent Flora of the Venezuelan Guayana ( Cuatrecasas and Huber 1999). The anther morphology of this species (Fig. 1C ), with its four separate sporangia, suggests an affiliation with Duckesia or Endopleura , and the transfer here to the former is supported by more similar connective morphology, absence of disporangiate anthers, and similar small leaves (Table 1 ). The two species of Duckesia are otherwise very distinct from each other; fruits remain unknown for D. liesneri and would likely provide additional distinguishing characters. The two collections of D. liesneri are ca. 60 km apart on isolated Venezuelan tepuis near the Brazilian border and north of D. verrucosa , which is a lowland Brazilian species.

Figures

Figure 1. Stamen structure of Humiriaceae. A Duckesia verrucosa tetrasporangiate anther, dorsal B Duckesia verrucosa tetrasporangiate anther, lateral C Duckesia liesneri tetrasporangiate anther, lateral D Endopleura uchi disporangiate anther, lateral E Endopleura uchi tetrasporangiate anther, lateral F Duckesia verrucosa sterile anther, lateral G Humiriastrum cuspidatum disporangiate anther, lateral H Humiriastrum cuspidatum androecium, dorsal I Endopleura uchi tetrasporangiate anther, lateral J Humiriastrum dentatum disporangiate anther, lateral K Humiriastrum dentatum disporangiate anther, ventral L Humiriastrum diguense disporangiate anther, lateral M Humiria balsamifera var. imbaimadaiensis stamen cluster with 2 of 3 types, dorsal. f = filament attachment location. Sources: A, B, F Ducke 2108 C Henderson 933 D, E, I Assuncao 605 G, H Cid et al. 4264 J, K Hatschbach 56145 L Quizhpe et al. 612 M Wurdack 4814 (all US.)