Adenocalymma apetiolatum L.H. Fonseca & L.G. Lohmann, 2016

Fonseca, Luiz Henrique M., Zuntini, Alexandre R. & Lohmann, Lúcia G., 2016, Two new species of Adenocalymma (Bignonieae, Bignoniaceae) from the Atlantic Forest of Brazil, Phytotaxa 284 (4), pp. 263-272 : 266-270

Adenocalymma apetiolatum L.H. Fonseca & L.G. Lohmann , sp. nov. ( Figs. 1A & 4 ).

Adenocalymma apetiolatum is morphologically similar to A. sessile Udulutsch & Assis and A. subsessilifolium DC. , but differs by a villous indument on the vegetative and reproductive parts (vs. pubescent to glabrous indument in A. sessile and A. subsessilifolium ), yellowish trichomes on the inflorescence (vs. cinereous trichomes in A. sessile , and ferruginous in A. subsessilifolium ), and orange corolla (vs. yellow corolla in A. sessile and A. subsessilifolium ). Adenocalymma apetiolatum also differs from A. sessile by the narrow-elliptic prophylls (vs. falcate prophylls in A. sessile ), large and elliptic floral bracts, with 8–13.7 × 3.8–5.6 mm (vs. short, ovate to obovate bracts with 2.6–4 × 1.8–2.5 mm in A. sessile ), and elliptic or slight falcate bracteoles with 4.3–9.2 × 2.1–3.1 mm (vs. ovate or obovate bracteoles with 2–2.6 × 1.1–1.8 mm in A. sessile ). Furthermore, Adenocalymma apetiolatum differs from A. subsessilifolium in having gibbous corolla (vs. infundibular corolla in A. subsessilifolium ).

Type:— Brazil. Espírito Santo: Águia Branca, Assentamento 16 de Abril, 175 – 180 m, 18°54’12.3’’S, 40°44’07.6”W, 04 October 2007, Boudet Fernandes H. Q., Demuner V., Cruz T. A., Vervloet R. 3508 (fl, fr) (MBML-32195).

Shrubs, 1.5–2 m tall. Stems terete, brown, with striated bark, with lenticels elliptic, 1.2–2.2 × 0.6–1.1 mm. Branchlets terete, villous, with eglandular trichomes simple or branched, interpetiolar region without glandular fields; prophylls of the axillary buds narrow-elliptic, 9.2–19.2 × 1.9–3.1 mm, villous and lepidote, with eglandular trichomes simple or branched, with cupular glandular trichomes, 1–2 × 0.69–3 mm diam. Leaves always 3-foliolated, with the terminal leaflet never modified into a tendril; petioles lacking; petiolules terete, with variable lengths, central petiolules 3.3–13 mm long, lateral petiolules 7.1–7.9 long, villous; leaflets elliptic, apex acute to acuminate, base cuneate, symmetric, membranous, adaxial surface glabrous to pubescent, with eglandular trichomes simple or branched, abaxial surface pubescent and lepidote, with eglandular trichomes simple or branched, with glandular trichomes cupular sparsely distributed, first venation order pinnate, second venation order brochidodromous, third venation order reticulate, veins not prominent, margins entire, straight, terminal leaflets 327–433 × 78.1–140.9 mm, lateral leaflets 343–548 × 114–142.3 mm. Inflorescence a branched lateral raceme, congested, with eglandular trichomes simple or branched; pedicels lacking; floral bracts persistent, covering young buds, elliptic, chartaceous, 8–13.7 × 3.8–5.6 mm, villous, with glandular trichomes cupular, 0.43–0.56 mm diam.; bracteoles persistent, elliptic or slight falcate, membranous, 4.3–9.2 × 2.1–3.1 mm, with glandular trichomes cupular, 0.38 mm diam. Calyx green, campanulate, 5-lobed, coriaceous, 10.7 × 8.4 mm, villous, with eglandular trichomes simple or branched, with glandular trichomes cupular, 0.59–0.77 mm diam. Corolla orange, gibbous, membranous, 37.7 mm long, tube 34.6 mm long, 9.9 mm of max width, 4.9 mm of width at the base, 7.1 mm of width at the mouth, pubescent, with eglandular trichomes simple or branched, with cupular trichomes glandular, without nectar guides, lobes deltoid, with equal sizes, 3 × 2.8 mm. Androecium inserted at 12.4 mm long, shorter filaments 17.6 mm long, longer filaments 22.1 mm long, staminode 2.7 mm long, glabrous, hirsute at insertion, with glandular trichomes stipitate, anthers curved forward, 2.9 × 1.1 mm, exerted. Gynoecium 33.6 mm long, ovary cylindrical, 2.5 × 1.1 mm, lepidote, with eglandular trichomes simple throughout, with glandular trichomes cupular at the apex, style 28.8 mm long, glabrous, stigma lanceolate, 2.3 × 1.3 mm, exserted. Fruit immature, green, oblong, inflated, rugose, 101.9 × 23.5 mm, villous, with eglandular trichomes simple or branched, with glandular trichomes cupular, 0.3–0.5 mm diam. Seeds unknown.

Etymology: —The species epithet refers to the sessile leaves.

Habitat and distribution:— Adenocalymma apetiolatum is only known from the type locality at Espírito Santo state, Brazil ( Fig. 5 ). This species is found between 175–208 m alt. in seasonally semi-deciduous Atlantic forest remnants surrounded by inselbergs.

IUCN red list category:— Adenocalymma apetiolatum is only known from the type locality. Tentatively, its conservation status is Data Deficient [DD] according to IUCN criteria ( IUCN 2012; IUCN Standards and Petitions Subcommittee 2014) until more information about this new species are gathered from more field surveys. Meanwhile, reduced population size, low number of individuals known, and anthropogenic pressure on the only known locality would very likely push this species towards extinction if conservation measures are not taken seriously.

Phenology:— The only specimen with flowers and young fruits was collected in October.

Morphological discussion:— Adenocalymma apetiolatum , A. sessile and A. subsessilifolium are understory shrubs from the semi-deciduous Atlantic Forest. These three Adenocalymma species are the only ones that have sessile leaves. Although these three species are superficially similar vegetatively, they differ on the type of indument. Besides that, differences are also largely observed in reproductive traits, especially in the floral bract morphology and dimension, corolla shape and color ( Table 2). It is worth noting that the gibbous corolla of A. apetiolatum is highly unusual in Bignonieae , and so far can be found only in Anemopaegma nebulosum Firetti-Leggieri & L.G. Lohmann in Firetti-Leggieri et al. (2015), Adenocalymma gibbosum Udulutsch & Assis in Udulutsch et al. (2013: 180), Adenocalymma salmoneum Gomes (1951: 314) , and A. sessile .

Additional material examined:— BRAZIL. Espírito Santo: Águia Branca, Assentamento 16 de Abril, 208 m, 14º39’51”S 61º09’33”W, 20 March 2015, Fonseca L. H. M. & Gomes B. M. 425 (st) ( SPF) ; Águia Branca, Assentamento 16 Abril, 208 m, 14º39’51”S 61º09’33”W, 20 April 2015, Fonseca L. H. M. & Gomes B. M. 431 (st) ( SPF) .

Figures

FIGURE 1. A: Adenocalymma apetiolatum. A. Sapling; B–F: Adenocalymma lineare. B. Sapling; C. Branchlet detail; D. Close-up of a young inflorescence, with ants; E. Close-up of an inflorescence at intermediate stage; F. Close-up of a mature inflorescence with open flowers (Photos by Luiz Fonseca).

FIGURE 4. Adenocalymma apetiolatum. A. Flowering branch. B. Close-up of interpetiolar node showing prophylls of the axillary buds. C. Side view of an open flower. D. Floral bract. E. Bracteole. F. Calyx artificially cut on one side and spread open. G. Front view of the corolla. H. Corolla artificially cut on one side and spread open. I. Nectar disk, ovary, style and stigma. J. Detail of stigma. K. Fruit. Illustrated from Boudet Fernandes H.Q. et al. 3508 (MBML).

FIGURE 5. Distribution of Adenocalymma apetiolatum, A. sessile, and A. subsessilifolium in the Brazilian Atlantic Forest.