Sinningia ganevii Chautems & Mat. Perret

Chautems, Alain, Cardoso, Domingos B. O. S. & Perret, Mathieu, 2022, Two new species of Sinningia (Gesneriaceae) endemic to Bahia, Brazil, Candollea 77 (2), pp. 137-144 : 138-140

Sinningia ganevii Chautems & Mat. Perret , sp. nov. ( Fig. 1 , 3 ).

Holotypus: BRAZIL. Bahia: Abaíra, distrito de Catolés, sítio Palmeiras, Serra do Porco Gordo , 13°23'S 41°46'W, 25.IV.1992, fl., Ganev 206 ( SPF [ SPF88316 ]!; iso-: HUEFS-10649!, US [ US00590762 ]!) .

Species with habit very similar to Sinningia harleyi Wiehler & Chautems , but differing by the presence of a short peduncle at the base of the cymes (0.4–0.5 cm long) and by having purple, tubular-campanulate corollas (vs. peduncle absent and bright red, tubular corollas in S. harleyi ).

Herb 20–60 cm tall, arising from perennial, irregularlyshaped tuber, 1–4 cm in diam., saxicolous; stems 3–5 mm in diam., usually unbranched, greenish to vinaceous, pubescent with glandulous trichomes, internodes 1.5–8 cm long. Leaves 4–9 pairs, decussate, equal or slightly anisophyllous; petiole 1.5–3 cm long, green to reddish, pubescent with glandulous trichomes; blade 2.5 –6.5(–11) × 1.8– 4(–7) cm, ovate, apex acute, base rounded to subcordate, margin distinctly crenate to nearly dentate, membranaceous, green and puberulous with glandular trichomes above, paler and puberulous with glandular trichomes between the nerves, but pubescent on the nerves beneath, 6–9 pairs of lateral veins. Inflorescence frondose, composed of cymes reduced to 1 (rarely 2) flowers, arranged in opposite pairs in the apical 3–9 leaf axils. Flowers borne on a short peduncle, 0.4–0.5 cm long, with 2 bracts 0.4 × 0.2 cm at the base of a single, rarely 2, ascending pedicel, 1.3–1.8 cm long. Calyx campanulate, fused at base along 2–3 mm, lobes 7–9 mm long, lanceolate, c. 3 mm wide at base, margin entire, green, glandular pubescent. Corolla yellowish during bud stage, tubular-campanulate at anthesis, erect in calyx (i.e. aligned with axis of calyx), 3.5–4 cm long, 0.4– 0.5 cm in diam. at base, tube 1–1.2 cm wide, dorsal side slightly arcuate, ventral side gradually expanding, light purple for most part, dark purple on the lobes inside, pubescent, lobes subequal, entire, 5– 6 × 8 –9 mm, patent to slightly revolute, throat cream to light violet with darker lines or fine dots or cream with pink dots. Stamens 4, included, filaments 1.5–1.8 cm long, white, glabrous, anthers coherent forming a rectangle, pollen cream, nectary composed of 5 whitish glands, the 2 dorsal ones fused at base, staminode greenish. Gynoecium with a greenish ovary, style included, 1.5–2 cm, white, puberulous. Fruit a dry capsule, 8–10 × 0.5 mm; seeds ellipsoid, c. 0.5 mm long.

Etymology. – The species is named after Wilson Ganev, guide to the Catolés collaborative research expedition between K, SPF and HUEFS (1991/1992) and plant collector in the Chapada Diamantina; his activities were supported by the Royal Botanical Gardens, Kew and the University of São Paulo.

Distribution and ecology. – Sinningia ganevii is known only from two locations in the district of Catolés within the municipality of Abaíra (578 km ²), which is part of the massif Chapada Diamantina in Bahia State ( Fig. 2 ). Scattered individuals were found growing between 950 and c. 1300 m on rocky (quartz) soil of the campo rupestre vegetation.

Phenology. – Flowering specimens were collected in April and May.

Conservation status. – Sinningia ganevii has a geographic range in the form of an Extent of Occurrence of less than 5,000 km² and a minimum Area of Occupancy of less than 500 km ². It is only known in little patches of campo rupestre vegetation threatened by fires and grazing. The protection of its habitat in the “Area de Proteção Ambiental Serra do Barbado” is not effective [https://g1.globo.com/bahia/ noticia/2013/10/incendio-atinge-areas-da-regiao-oeste-eda-chapada-diamantina-na-bahia.html]. The new species is therefore assigned a provisional status of “Endangered” [EN B1ab(i,ii,iii)+2ab(i,ii,iii)] using the IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. – This species is very similar in habit and leaf shape to Sinningia harleyi (CHAUTEMS, 1991). Material collected in the 1990’s was identified and stored in the herbaria HUEFS, K and SPF under this name, however, a closer examination by the first author revealed the strikingly different corolla morphology (see diagnosis above). Preliminary phylogenetic results support a sister-group relationship between S. ganevii and S. harleyi and suggest a case of recent evolutionary transition between hummingbird for the latter and bee syndromes for S. ganevii (SERRANO-SERRANO et al., 2017: fig. S4). Based on the present distribution of the two species with occurrences registered at only a few km away, this speciation event may have happened in sympatry. So far, S. ganevii was found in a small area in the municipality of Abaíra at elevations between 900 and 1300 m, whereas S. harleyi occurs in a wider extension of the Chapada Diamantina including the municipalities of Abaíra, Jussiape and Rio de Contas, at elevations between 900 and 1500 m ( Fig. 2 ). The area around the locality of Catolés harbors a rich and poorly known flora as suggested by many recently described species in other families as detailed in the Introduction.

Additional specimens examined. – BRAZIL. Bahia: Abaíra, Riacho do Piçarrão de Osmar Campos , 13°23'S 41°48'W, 8.V.1994, Ganev 3229 ( HUEFS, SPF, UESC, US); Abaira, Distrito Catolés , Chemin de Arapiranga a Catolés, campo rupestre, 13°23'20"S 41°47'43"W, 956 m, 1.V.2012, Perret et al. 51 ( G, VIES). [ BRAZIL]: cultivated in CJBG from Perret et al. 51, 7.XI. 2012, Chautems 550 ( G) .

Figures

Fig. 1. – Sinningia ganevii Chautems & Mat. Perret. A. Habit, flowering stage; B. Longitudinal cut of corolla showing androecium and gynoecium; C. Ventral and dorsal view of coherent anthers; D. Ovary and nectary, corolla removed; E. Schematic arrangement of the nectary glands. [Chautems 550, G] [Drawing: G. Loza]

Fig. 3.– Image featuring the similar erect habit of Sinningia ganevii (left) and S. harleyi (right) and their distinct floral morphology corresponding to bee and hummingbird pollination syndrome, respectively. Cultivated in CJBG] [Photo: M. Perret]

Fig.2.– Distribution of Sinningia ganevii Chautems & Mat. Perret (black triangle) and S. sulphurea Chautems & D.B.O.S. Cardoso (black square), including their related species S. harleyi Wiehler & Chautems (white triangle) and S. barbata (Nees & Mart.) G. Nicholson (white square).