Pseudotragia scandens Pax, Bull. Herb. Boissier

Pseudotragia scandens Pax, Bull. Herb. Boissier View in CoL , ser. 2, 8: 636. 1908. TYPE: NAMIBIA. Amboland , Oohama, March 1886, H. Schinz 894 (holotype: G; isotypes: K! [barcode K001044973], Z [barcode Z-000085918; image!]).

Notes —See Gillespie (2007) for species description. Although Sonder did not explicitly cite holotypes, his types based on Ecklon and Zeyher collections from South Africa are presumed to be housed in S ( Nordenstam 1980), with duplicates found in many other herbaria in Europe and Melbourne, Australia. Indeed, the specimen at Stockholm, which we consider the holotype, has the most abundant floral and fruit material and original labels.

4. PLUKENETIA CORNICULATA Sm. , Nova Acta Regiae Soc. Sci. Upsal. 6: 4. 1799. Pterococcus glaberrimus Hassk. View in CoL , Flora 25 (2): 41. 1842. Hedraiostylus glaberrimus (Hassk.) Hassk., Tijdschr. Natuurl. Gesch. Physiol. View in CoL 10: 141. 1843. Hedraiostylus corniculatus (Sm.) Hassk., Cat. Hort. Bot. Bogor. 234. 1844. Sajorium corniculatum (Sm.) D.Dietr., Syn. Pl. View in CoL 5: 331. 1852. Sajorium corniculatum (Sm.) Baill., Étude Euphorb. 484. 1858, nom. illeg. Pterococcus corniculatus (Sm.) Pax & K.Hoffm. in A.Engler (ed.), Pflanzenr. IV, 147, IX (Heft 68): 22. 1919. TYPE: INDONESIA. Amboina, Bagulae Regione, Illustration t.79, Fig. 2 View FIG in Rumphius, Herb. Amboin. 1: 193. 1750.

Notes —See Gillespie (2007) for species description.

Taxonomic Discussion — Plukenetia corniculata is one of the oldest names in Plukenetia and has a complicated taxonomic history. Originally described as the pre-Linnaean Sajor volubilis ( Rumphius 1750) , it was included as a synonym of Plukenetia volubilis by Linnaeus (1753). Smith (1799) gave Rumphius’ species its first legitimate name, P. corniculata , but four other genera would be erected for Sajor: Pterococcus ( Hasskarl 1842) , Hedariostylus ( Hasskarl 1843), Sajorium ( Endlicher 1843) , and Ceratococcus ( Meisner 1843) . Hasskarl’ s first name, Pterococcus (1842), was previously published by Pallas (1773) in Polygonaceae , so he proposed the replacement name Hedraiostylus in; September 1843 ( Stafleu and Cowan 1979). Subsequent replacement names Sajorium and Ceratoccocus, both nomenclaturally superfluous, were published in October and 2–4 November of 1843, respectively ( Stafleu and Cowan 1976, 1981).

Baillon (1858) first treated Hedraiostylus as a section of the illegitimate genus Sajorium [5 Plukenetia ], giving Hedraiostylus priority as a sectional name. The fact that Sajorium was illegitimate precludes the rejection of sect. Hedraiostylus in favour of the autonym Sajorium sect. Sajorium (ICN 2017, Art. 22.5; Turland et al. 2018). When Müller created the first sectional classification of Plukenetia he initially erected sect. Sajor ( Müller 1865), but quickly updated it to sect. Hedraiostylus ( Müller 1866) . To complicate matters, Pterococcus Hassk. was conserved over Pterococcus Pall. , but as a sectional name, Hedraiostylus retains priority.

5. PLUKENETIA PROCUMBENS Prain, Bull. Misc. Inform. Kew 1912 View in CoL (5): 240. 1912. Pterococcus procumbens (Prain) Pax & K.Hoffm. in A.Engler (ed.), Pflanzenr. IV, 147, IX (Heft 68): 23. 1919. TYPE: ANGOLA. Benhuella, Ganguella, on the Cubagano River at Princeza Amelia, 1520 m, 27 January 1907, J. Gossweiler 2540 (holotype: BM! [barcode 000535903 (BM)]; isotypes: COI! [barcode COI00072615], K! [barcode K000425657; fragments with floral sketch]). Notes —See Gillespie (2007) for species description.

IV. Plukenetia sect. Madagascarienses Card. -McTeag. & L.J.Gillespie sect. nov. TYPE: Plukenetia madagascariensis Leandri.

Lianas, stems slender to thick. Leaf venation palmate, primary veins 3(–5). Inflorescences bisexual racemes or racemose thyrses; pistillate flowers solitary at 1–2 basal-most nodes; staminate flowers 1/node or 3–5/node in lax or moderately condensed cymules with conspicuous and irregularly branched cyme axes. Staminate flowers: receptacle ellipsoid, oblong-cylindrical, or ovoid-conical; nectaries absent; stamens 15–60, densely or loosely packed; filaments absent; pollen P 5 28–41 m m, E 5 35 –51 m m, tectum foveolate. Pistillate flowers: styles entirely connate into an obconic or obovoid column, 3.5–5.5 mm long, or 55–60% connate into a cylindrical column, 8–16 mm long, free style arms slender and tapered. Fruits 4- lobed capsules, dry, dehiscent, 2.3–4 cm in diam. Seeds broadly ellipsoid or subglobose, 13.1–18 3 11.1–17 3 11.2–17 mm (“large” sensu Cardinal-McTeague et al. 2019a).

The species in this section are distributed in Madagascar.

Etymology —The sectional epithet is derived from the combination of Madagascar and - ensis (Latin, of a place), which reflects that all the species in the section are endemic to Madagascar.

Discussion —Section Madagascarienses refers to a strongly supported clade within subclade P5 ( Fig. 1 View FIG ) and includes three species endemic to Madagascar. This section was originally defined as the Madagascan species group ( Gillespie 2007) and was noted for exhibiting sessile anthers similar to the pinnately veined clade. Style morphology is variable in the section, including both partly ( P. decidua , P. madagascariensis ) and entirely connate ( P. ankaranensis ) styles ( Fig. 3N–O View FIG ). Section Madagascarienses is differentiated by having sessile anthers on a prominently elongated receptacle ( Fig. 2L View FIG ), larger dry dehiscent fruits, “large” seeds, and by being endemic to Madagascar. All three species occur in seasonally dry environments, either dry forest on tsingy limestone ( P. ankaranensis , P. madagascariensis ) or in dry scrub ( P. decidua ).