Tetracarpidium staudtii Pax, Bot. Jahrb. Syst.

Tetracarpidium staudtii Pax, Bot. Jahrb. Syst. View in CoL 26 (3–4): 329. 1899. TYPE: CAMEROON. Station Johann-Albrechtschöhe , 15 January 1897, A. Staudt 802 (holotype: B [destroyed]; lectotype designated here: BM! [barcode 000535187 (BM)]; isolectotypes: G [barcode G00414564; image!], K! [barcode K000425656; sketch of holotype with floral fragments], MO! [accession 1648824, barcode MO-2289110 ], PH [accession 01078710, barcode 00030257; image!]).

Notes —See Gillespie (2007) for species description.

Taxonomic Discussion — Plukenetia conophora and sect. Angostylidium were simultaneously described by Müller (1864). Subsequent authors described taxa that are now treated as synonyms, including Mallotus preussii ( Pax 1897) and the novel genus and species Tetracarpidium staudtii ( Pax 1899) . Furthermore, Baker (1910) described Cleidion mannii from P. conophora syntype material (“River Cameroon.” G. Mann 2202) but erroneously cited the type as “ Cameroons river, G. Mann 1202 ” (that specimen is recorded as Pittosporum viridiflorum “mannii ” Sims, “Mount Cameroon,” G. Mann 1202 (K000106232). Baker appears to have described Cleidion mannii from the only G. Mann 2202 sheet at Kew that was not annotated as Müller’ s P. conophora (K000425659).

The holotype of Mallotus preussii is presumed to have been in Berlin, where Pax worked and Preuss’ s main collections were housed. Since the type was likely destroyed, we designate a lectotype from an isotype housed at Kew, given it has abundant staminate flowers. Under a similar circumstance we designate a lectotype for Tetracarpidium staudtii , selecting the isotype with the most abundant leaf and pistillate flower material housed at the British Museum. Alois Staudt was the collection assistant of G. Zenker in Cameroon, so we presume his collections were part of Zenker’ s main set that was destroyed in Berlin.

II. Plukenetia sect. Fragariopsis (A.St.-Hil.) Card. -McTeag. & L.J.Gillespie, comb. et stat. nov. Fragariopsis A.St.-Hil., Leçons Bot. 426. 1840. TYPE: Fragariopsis scandens A.St.-Hil. [5 Plukenetia serrata (Vell.) L.J.Gillespie ]

Lianas, stems slender to thick. Leaf venation pinnate, primary vein 1. Inflorescences bisexual racemose thyrses; pistillate flowers solitary at 1–10 basal-most nodes; staminate flowers 2(3)/ node in condensed cymules. Staminate flowers: receptacle globose; nectaries absent; stamens 10(–20), loosely packed (receptacle clearly visible between anthers); filaments absent; pollen P 5 32–46 m m, E 5 42 –55 m m, tectum coarsely reticulate. Pistillate flowers: styles entirely connate into an obovoid column, 3–3.5 mm long. Fruits 4–lobed or subglobose-quadrangular, capsule-like, initially fleshy, apparently indehiscent or tardily splitting, 4–5 cm in diam. Seeds subglobose, 15–15.5 3 15.5–16 3 15–16 mm (“large” sensu Cardinal-McTeague et al. 2019a).

The single species in this section is distributed in the Atlantic Forest of Brazil.

Etymology —The sectional epithet is derived from Fragaria (Latin, strawberry) and - opsis (Greek, appearing like or resembling), referring to the androecium, which has the appearance of a small strawberry. We chose the name Fragariopsis because it describes the androecium morphology that is unique to the section and because historically it was the more widely known genus that contained Plukenetia serrata .

Discussion —Section Fragariopsis refers to subclade P1 ( Fig. 1 View FIG ) and includes a single species, P. serrata , from the Atlantic Forest region of Brazil. This species/section has long been recognized as a distinct genus ( Table 1), but belongs within Plukenetia due to their numerous shared characters ( Gillespie 1993) and phylogenetic relationships ( Cardinal-McTeague and Gillespie 2016; Cardinal-McTeague et al. 2019a). Together, sects. Fragariopsis and Penninerviae constitute the pinnately veined clade (P1 1 P2), which is united by pinnate leaf venation, coarsely reticulate pollen tecta, all or mostly sessile anthers, and entirely connate styles. Section Fragariopsis is differentiated by its unique androecium composed of sessile anthers loosely packed on a globose receptacle ( Fig. 2B View FIG ), as well as by having 1–10 pistillate flowers, “large” seeds derived from fleshy fruits, and for being the only section distributed in the Atlantic Forest region of Brazil.