Sinningia stapelioides Chautems & M. Peixoto, 2019

Chautems, Alain, Valquíria F. Dutra,, Fontana, André P., Peixoto, Mauro, Perret, Mathieu & Rossini, Josiene, 2019, Three new species of Sinningia (Gesneriaceae) endemic to Espírito Santo, Brazil, Candollea 74 (1), pp. 33-42 : 39-41

Sinningia stapelioides Chautems & M. Peixoto , spec. nova

( Fig. 2D , 5 ).

Holotypus: [ BRAZIL. Espírito Santo]: cult. in CJBG under Acc. nº AC-3518 originating from Pancas, Pedra da Agulha , 17.I.2012, fl., A. Chautems 555 ( VIES!; iso-: G spirit!) .

Sinningia stapelioides resembles S. defoliata (Malme) Chautems , S. helioana Chautems & Rossini and S. tuberosa (Mart.) H.E. Moore in having inflorescences and leaves arising separately and successively from the tuber with rarely more than one leaf blade produced by a petiole-like stem. It differs however by a pauciflorous inflorescence with distinctive flowers having a large (5–6 cm) tubular-campanulate corolla, dull red orange outside with a peculiar throat that is greenishcream with a dense network of vinaceous streaks that extends on the inner face of the lobes (vs long, up to 3–4 cm, tubular and bright red corollas).

Herb, arising from perennial tuber, saxicolous; tuber spheroidal, 4–12 cm in diam., leaves and inflorescences produced separately and successively, 1- rarely 2-petiole-like stems, obliquely arising from the tuber upper surface, 4–12 cm long, 3–4 mm in diam., vinaceous, pubescent, blade attachment swollen abaxially, 1–2 pairs of linear-lanceolate bracts just below blade insertion. Leaves forming an angle of nearly 90° with the petiole-like stem, usually reduced to one large blade at maturity (during first growing cycle from seed seedlings produce 2–3 pairs of opposite leaves, followed on subsequent growing cycles from tuber by a phase with a second and small leaf blade, 1–5 mm long, produced in opposite position), ovate (3–)9–24 (– 36) × (1–)4–11(– 18) cm, apex acute-acuminate, base shortly attenuate to truncate, green above, green or reddish beneath, finely puberulous-velutinous, margin slightly crenate, 10–15 pairs of veins. Inflorescences organized in well-developed pairflowered cymes of 1–3 flowers borne on a peduncle, 5–8 cm long, 1–2 mm in diam., greenish to vinaceous, emerging from 1–2 points of the tuber upper surface, bracts linear, 1–2 mm long. Flowers nodding, borne on pedicels, 2–4 cm long, greenish to vinaceous, puberulous. Calyx campanulate, sepals fused at base for 2– 3 mm, narrowly triangular, 13–15 × 6– 7 mm, wide at base, greenish to reddish, margin entire, puberulous. Corolla slightly oblique in the calyx , tubular, 5– 6 cm long, nectary chamber composed of 5 swellings, green, 9–10 mm wide at base, tube enlarged then towards the middle reaching 16–20 mm in diam., vinaceous in bud, dull red orange outside (RHS color chart # 35 B-C) at maturity, puberulous with simple and glandular trichomes, lobes 9–10 × 18–20 mm, throat cream to greenish towards bottom, lobes spreading with a network of vinaceous streaks and dots on inner face. Stamens 4, included, filaments ca. 50 mm, greenish, glabrous, anthers coherent, star-shaped, pollen cream; nectary formed of five glands, equals in size, greenish; ovary vinaceous, style included, 40– 50 mm long, vinaceous, puberulent, stigma greenish. Fruit a capsule, subulate at the apex, dark brown at maturity, 14–18 × 9–11 mm, seeds ellipsoid, 7–9 mm long.

Etymology. – The specific epithet refers to the color pattern of the corolla that resembles flowers of some members of the genus Stapelia L. ( Apocynaceae ).

Distribution and ecology. – Only known so far from the type locality in the region of the “Pontões Capixabas”, an area classified as National Monument around the small town of Pancas, in the northern part of the state of Espírito Santo, Brazil ( Fig. 1 ). The area is famous for large rock inselbergs, some reaching several hundred meters in height. A few tubers were observed growing on a vertical side of a granite block measuring ca. 5 m in height in shady situation, not far from a forested fragment partially converted to cocoa trees cultivation, within a small farm.

Phenology. – Flowers observed in August (in cultivation in Brazil) or December (in cultivation in Geneva) and mature fruits in October (in cultivation in Brazil).

Conservation status. – Less than ten individuals were observed in a single population growing on a large granitic block within a fragment of humid forest, with the understory partly planted with cocoa trees. This single location lies within a farm at a few hundred meters from the farmer residence. Most of the land is already converted to tropical crops, like banana and coffee. This reduced plant population is then heavily threatened by any change in the surroundings, like tree felling or extension of any other tropical crop. With an EOO <100 km 2 and AAO <10 km ², S. stapelioides is assigned a preliminary assessment as “Critically Endangered” [CR B2ab(iii)] using the IUCN Red List ( IUCN, 2012).

Notes. – This species generates leaves and inflorescences separately and successively on the tuber surface, following the tuber dormancy period during the dry season (May-September). This feature is also present in three other Sinningia species, i.e., S. defoliata (Malme) Chautems , S. helioana and S. tuberosa (Mart.) H.E. Moore. This separate and successive development of vegetative and fertile shoots could have evolved at least twice independently in the genus. Indeed, preliminary phylogenetic data place this new taxon in the clade Corytholoma , together with S. defoliata and S. helioana , whereas S. tuberosa belongs to clade Sinningia ( PERRET et al. 2003; M. Perret, unpubl. data). Nevertheless, S. stapelioides produces large (5–6 cm) tubular-campanulate corollas with a peculiar throat and lobes coloration pattern that differ from the long (up to 3–4 cm) tubular and bright red corollas displayed by these three species.

Live material of this species was first obtained from the late R.A. Kautsky (later established to have been originally collected in the type locality within Sr. Adriano Romais’ property). It was introduced in cultivation under the provisional name Sinningia sp. “Pancas”.

The only available material collected in the wild is a sterile gathering, as all individuals at the time of the collection were in a vegetative phase. This sample is designated as a paratype. Fertile material could only be observed at a different period on a plant cultivated in Geneva originating from the same locality. A flower was then collected and designated here as the holotype.

Paratypus. – BRAZIL. Espírito Santo: Pancas, base da Pedra da Agulha , propriété do Sr. Adriano Romais , 4.V.2012, ster., Perret, Chautems, Peixoto & Duarte 55 ( VIES-026563 ) .

Figures

Fig. 2. – Photographs of Sinningia Nees. A. Sinningia flammea Chautems & Rossini; B–C. Sinningia hoehnei Chautems, A.P. Fontana & Rossini; D. Sinningia stapelioides Chautems & M. Peixoto. [Pictures: A–C: A. P. Fontana; D: M. Peixoto]

Fig. 5. – Sinningia stapelioides Chautems & M. Peixoto. A. Habit, leaf stage; B. Habit, flowering stage; C. Frontal view of corolla; D. Longitudinal cut of corolla showing androecium and gynoecium; E. Lateral view of corolla; F. Dorsal surface of anthers; G. Ovary and nectary, corolla removed; H. Schematic arrangement of the nectary glands; I. Calyx, ovary and style.

Fig. 1. – Distribution map of Sinningia flammea Chautems & Rossini (triangles), S. hoehnei Chautems, A.P. Fontana & Rossini (squares) and S. stapelioides Chautems & M. Peixoto (star).