Pseudephedranthus enigmaticus Maas & Westra, sp. nov.

Erkens, Roy H. J., Oosterhof, Jessica, Westra, Lubbert Y. T. & Maas, Paul J. M., 2017, Revisions of Ruizodendron and Pseudephedranthus (Annonaceae) including a new species and an overview of most up-to-date revisions of Neotropical Annonaceae genera, PhytoKeys 86, pp. 75-96 : 85-88

Pseudephedranthus enigmaticus Maas & Westra, sp. nov. Figs 4 , 5

Diagnosis.

Differing from P. fragrans by shorter petioles. Moreover, petals in P. enigmaticus are for a large part covered by a very dense indument of curly hairs, those of P. fragrans covered by a less dense indument of appressed hairs. Also, seeds in P. enigmaticus are ellipsoid instead of ovoid and smaller than in P. fragrans .

Type.

SURINAME, Sipaliwini, Central Suriname Nature Reserve , ca. 4 km ENE of Kayserberg Airstrip, alt. 235 m, 4 June 2003, Evans et al. 3437 (holotype WAG! [barcode WAG.1584983]; isotype L! [barcode L.3724851]) .

Description.

Tree, 3-15 m tall, 12-20 cm diam.; young twigs glabrous. Leaves: petioles 3-5 by 1-2 mm; lamina narrowly elliptic, 12-22(-26) by 4-6(-9) cm (index 2.8-4), chartaceous, pale gray to greenish gray above in sicco, somewhat bullate above in vivo, greenish brown to pale brown below in sicco, base acute, apex acuminate (acumen 5-10 mm long), primary vein raised above, secondary veins 6-10 on either side of primary vein, raised above, smallest distance between secondary veins and margin 4-7 mm, tertiary veins raised, rarely flat above, reticulate. Only staminate flowers seen, Inflorescence axillary, 1-2(-several)-flowered, pedicels 3-12 mm by 0.5-2 mm, rather densely to sparsely covered with erect to appressed, brown hairs to ca. 1 mm long, soon glabrous; bracts 4-5, depressed ovate, 1-2 mm long, outer side rather densely to sparsely covered with erect to appressed, brown hairs; flower buds ellipsoid; sepals shallowly ovate-triangular, ca. 2 by 2-3 mm, outer side rather densely to sparsely covered with erect to appressed, brown hairs; petals white, tinged with pale green in vivo, oblong-elliptic to narrowly so, 7-12 by 3-6 mm, outer side of outer petals densely to rather densely covered with appressed, brown hairs, inner side densely covered with whitish or greyish-white, curly hairs except for the glabrous base, outer side and apical part of inner petals densely covered with curly, white hairs; staminate torus conical, 2-2.5 mm long, ca. 1 mm diam. at base; stamens ca. 50, 2-2.5 mm long, apical prolongation of connective discoid, broadly elliptic. Monocarps 3-15, green in vivo, black in sicco, ellipsoid, 12-32 by 7-15 mm, glabrous or sparsely covered with appressed hairs, apex rounded, wall 0.2-0.5 mm thick, stipes 1-4 mm long, 1-1.5 mm diam. Seed ellipsoid, 12-19 by 7-10 mm, pale brown, transversely striate.

Distribution.

Guyana, Suriname, and the Brazilian state of Pará. Fig. 1 .

Habitat and ecology.

In periodically inundated or non-inundated forest, on sandy or loamy soil, alt. 100-600 m. Flowering: May, June; fruiting: June, July, September.

Specimens examined.

Brazil. Pará: Parque Indígena do Tumucumaque, Rio Parú de Oeste, Missão Tiriyo, Cavalcante 2579 (U); Rio Maicuru , Igarape do Mutum , 31/2 hrs. por canoa de motor de poupa acima da pista de pouso do Lageiro, Jangoux & Ribeiro 1555 (L, RB); W bank of Rio Maicuru , ca. 23 km upstream from Lageira airstrip, N side of Mutum stream, Strudwick et al. 3808 (U) . Guyana. Takutu-U Region, Rupununi River , between Kwattamang Landing and Rewa Village, 100 m, Clarke et al. 6750 (NY, US) . Suriname. Suriname , Sipaliwini District, Sipaliwini River, Werehpai , 5 September 2010, Bánki et al. 1674 (L) ; Sipaliwini District, Si paliwini River , Bánki et al. 1579 (L) ; Sipaliwini, vicinity of camp on W bank of Zuid River, across river (i.e. W and outside of) Central Suriname Nature Reserve , ca. 10 km straight-line distance SSE of Kayserberg Airstrip, 240 m, Evans et al. 3485 (L) ; Sipaliwini, Central Suriname Nature Reserve, on S slope of the first peak in Eilerts de Haan mountain range , ca. 7 km ENE of Kayserberg Airstrip, 400-600 m, Herrera C. et al. 9959 (L, WAG); Distr . Nickerie, area of Kabalebo Dam project, 30-130 m, Lindeman & de Roon 752 (U) ; Sipaliwini, Morro Grande camp forest island, 6 km W of Morro Grande dome, 360 m, Oldenburger et al. 416 (U) ; Sipaliwini, Central Suriname Nature Reserve, 2-5 km SE of E end of Kayserberg Airstrip , 235 m, Rosário 1796 (L) ; Sipaliwini, Central Suriname Nature Reserve , 2-5 km ENE of Kayserberg Airstrip, 235 m, Rosário et al. 1829 (MO) ; Sipaliwini, Central Suriname Nature Reserve, vicinity of camp at southern base of the first peak in Eilerts de Haan mountain range , 250-350 m, C.S. & D.O. Rosário 2176 (L) .

Notes.

Material of this species had previously been filed in herbaria under different generic names such as Cremastosperma , Guatteria , Klarobelia , Malmea , Oxandra , and Rollinia (which is quite aberrant!). The confusion is aptly expressed in the epithet " enigmaticus ". This new species fits quite well, however, within the genus Pseudephedranthus (segregated from Ephedranthus by Aristeguieta in 1969), among others by the leaf venation, fruit and seed structure, and the strong similarity of the flowers. We acknowledge the fact that Pirie et al. (2006) demonstrated that Pseudephedranthus fragrans is nested in Klarobelia . From a morphological point of view (leaves and venation; flower morphology) this is quite surprising, given that overall morphology of Klarobelia is homogenous, and Pseudephedranthus is deviant from the general Klarobelia morphology. Therefore, we prefer to describe this new species in Pseudephedranthus to reflect the morphological similarity to P. fragrans . P. enigmaticus is distinct from P. fragrans by shorter petioles and, particularly, by the much denser indument of small curly hairs on most of the inner side of the petals (versus mostly small straight hairs). Also, seeds in P. enigmaticus are ellipsoid and 12-19 by 7-10 mm in contrast to P. fragrans were they are ovoid and larger (25-30 by 13-15 mm).

The specimens investigated here were either fruiting or flowering, the flowers all being staminate. Carpel bearing flowers are still needed to complete the description.

Figures

Figure 1. Distribution map of Ruizodendron ovale, Pseudephedranthus fragrans and P. enigmaticus.

Figure 4. a Close up of flowering branch of Pseudephedranthus enigmaticus (Evans et al. 3437) b Close up of fruiting branch of Pseudephedranthus enigmaticus (Herrera C. et al. 9959).

Figure 5. Drawing of Pseudephedranthus enigmaticus. a Flowering branch (Clarke 3420, U) b Flower in lateral view c Staminate flower in longitudinal section d Outer petal e Inner petal f Stamen (b-f Evans et al. 3437, WAG) g Fruit (Herrera C. 9959, WAG) h Seed, small part of seed coat removed to show lamellate ruminations i Cross section of monocarp and enclosed seed showing 4 - parted rumination (h-i Strudwick et al. 3808, U). Drawings by Esmee Winkel.