Keraunea velutina Moonlight & D.B.O.S.Cardoso, 2023

Moonlight, Peter W. & Cardoso, Domingos Benicio Oliveira Silva, 2023, A taxonomic revision of Keraunea, including three new species and its phylogenetic realignment with Ehretiaceae (Boraginales), PhytoKeys 219, pp. 145-170 : 145

5. Keraunea velutina Moonlight & D.B.O.S.Cardoso sp. nov.

Fig. 7

Diagnosis.

Most similar to Keraunea capixaba but differing in its velutinous indumentum on the stems, side shoots and lower leaf surface (versus glabrescent); its strigose indumentum on the upper leaf surface (versus glabrescent); its elliptic to narrowly lanceolate leaves on the side shoots (versus ovate).

Type.

Brazil. Rio de Janeiro: Mun. Cardoso Moreira, Santíssimo, Fazenda Borges , [21°29'S, 41°37'W], 10 Sep. 2013, J.G. Costa 257 (holotype: RB [00852871]) .

Description.

Scandent shrub or liana, size unknown. Stems cylindrical, hollow, 2-3 mm in diameter, rarely branching, velutinous-pubescent; internodes 2-5.9 cm long; side shoots 2.2-4.7 cm long velutinous-pubescent. Leaves of the main stem with the blades 7.9-8.1 × 2.7-3.1 cm, lanceolate, velutinous-pubescent, the venation pinnate, camptodromous, with 6-8 secondary veins; the base obtuse, the margins entire, ciliate, the apex attenuate; petioles of leaves on main stem 10-11 mm long, distinctly curved to 90° ¼ of the way along their length. Side shoots with 6-8 leaves, these progressively larger along the shoot; blades 0.5-3.5 × 0.3-1.7 cm, elliptic, rarely or lanceolate or obovate, strigulose-pubescent above, velutinous below, the base cuneate to rounded, the margins entire, ciliate, the apex rounded to attenuate. Inflorescence corymbose, with 2-4 flowers; free portion of the peduncle 3-5 mm long; pedicel 0.5-1.5 cm long, the remainder adnate to the bracteole, sericeous-pubescent; bracteole 2-3.8 × 0.7-1.6 cm, inserted ca. ⅓ of the way along the pedicel or rarely lacking, ovate, velutinous- pubescent, the venation as the leaves, the base short-cuneate, margin entire, ciliate, the apex attenuate. Flowers 5-merous. Calyx with the tube campanulate, ca. 1.5 mm long, the lobes 0.7-1.4 × 6.7-12 mm, ensiform, velutinous-pubescent. Corolla with the tube campanulate, 5-5.9 mm long, the lobes 14 × 7 mm, elliptic, glabrous. Stamens epipetalous, inserted at the base of the corolla tube, filaments 3-4 mm long, anthers ca. 7 mm long, connective extending to 1.3 mm; ovary subglobose, 2-locular, the locules biovulate; style single, conduplicate, unbranched; stigmas 2, truncate. Fruit inserted on the accrescent bracteole; calyx persistent, expanding to 15 mm long.

Distribution.

Keraunea velutina is endemic to Brazil and known only from the type from Cardoso Moreira municipality in the state of Rio de Janeiro (Fig. 2 ).

Habitat.

The single specimen known of K. velutina was collected within a forest fragment around isolated inselbergs. Cardoso Moreira municipality includes several granitic inselbergs and deforestation appears reduced around these compared to the surrounding land. We suspect that, like the similar Keraunea capixaba , this species was collected scrambling over rocks at the base of an inselberg.

Conservation status.

Keraunea velutina is known from a single specimen collected within a small forest fragment. Forest cover within Cardoso Moreira municipality declined from 5.2% in 1985 to 4.0% in 2012 before recovering to 4.6% by 2021 ( Mapbiomas 2022). This picture is however complex, with Google Earth imagery showing that deforestation of primary forest is continuing in some areas, but forest is recovering in other areas ( Google Earth Pro 2020). As such, due to single collection with imprecise locality information from a largely deforested municipality, we provisionally assess K. velutina as Critically Endangered (CR B1 B2 a b ii) under IUCN criteria ( IUCN 2019).

Etymology.

Named for the plant’s velvety indumentum.

Identification notes.

Keraunea velutina is a distinct species easily distinguished from all others in the genus by the dense, velvety indumentum of the stems and lower leaf surfaces. It is also distinctive in its side shoots with more numerous leaves than other members of the genus (6-8 versus 2-5), which are almost all elliptic (versus variously ovate to broadly ovate).

Figures

Figure 2. Distribution of species of the genus Keraunea. Shading denotes elevation; two letter codes represent the standardised two letter codes for the states of Brazil. Species are coloured as follows: blue, K. brasiliensis Cheek & Simao-Bianchini; black, K. bullata Moonlight & D. B. O. S. Cardoso; yellow, K. capixaba Lombardi; red, K. confusa Moonlight & D. B. O. S. Cardoso; green, K. velutina Moonlight & D. B. O. S. Cardoso.

Figure 7. Holotype of Keraunea velutina Moonlight & D. B. O. S. Cardoso, J. G. Costa 257 (RB [00852871]).