Adenocalymma lineare L.H. Fonseca & Zuntini, 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 : 264-266

Adenocalymma lineare L.H. Fonseca & Zuntini , sp. nov. ( Figs. 1B–F & 2 ).

Adenocalymma lineare is morphologically similar to A. nervosum Bureau & Schumann , but differs from the latter in the habit which is a decumbent shrub (vs. erect shrub in A. nervosum ), narrow-elliptic prophylls (vs. falcate prophylls in A. nervosum ), leaflets with veins immersed (vs. veins prominent in A. nervosum ), floral bracts elliptic with 9–11.6 × 2.1–3.2 mm (vs. floral bracts ovate with 4.1–5.1 × 1.9–2 mm in A. nervosum ), bracteoles with 7–7.4 × 1.8–1.9 mm (vs. bracteoles with 3.1–3.4 × 1.1–1.2 mm in A. nervosum ), corolla orange and tubular with recurved lobes (vs. corolla yellow and infundibular with patent lobes in A. nervosum ), anthers and stigma exerted from the flower tube (vs. anthers and stigma included in the flower tube in A. nervosum ).

Type:— Brazil. Espírito Santo: Águia Branca, Assentamento 16 de Abril, 197 m, 18°54’0.05’’S, 40°44’12.3”W, 20 April 2015, L. H. M. Fonseca & B. M. Gomes 429 (fl) (holotype SPF; isotypes MO, RB) .

Shrubs, 0.8–3 m tall. Stems terete, brown, with striated bark, with lenticels elliptic, 0.8–1.4 × 0.66–0.9 mm. Branchlets terete, pubescent, with eglandular trichomes simple, interpetiolar region without glandular fields; prophylls of the axillary buds narrow-elliptic, 6.2–10.4 × 1.3–1.8 mm, pubescent and lepidote, with eglandular trichomes simple, with glandular trichomes cupular, 2–4, 0.16–0.59 mm diam. Leaves always 3-foliolated, with terminal leaflet never modified into a tendril; petioles terete, 15.4–44.1 mm long, pubescent; petiolules terete, with variable lengths, central petiolules 1.8–9.6 mm long, lateral petiolules 1–5.3 mm long, pubescent to glabrous; leaflets linear, apex acute, base attenuate, symmetric, membranous, adaxial surface glabrous, abaxial surface pubescent, with eglandular trichomes simple or branched at the central vein, first venation order pinnate, second venation order brochidodromous, third venation order reticulate, veins immersed in the blade, margins entire, straight or slightly revolute, terminal leaflets 137–320 × 7.6– 12.7 mm, lateral leaflets 118–312 × 6.2–12.3 mm. Inflorescence a branched lateral raceme, congested, with eglandular trichomes simple; pedicels 7 mm long; floral bracts caducous, not covering young buds, elliptic, 9–11.6 × 2.1–3.2 mm, membranous, puberulent, with glandular trichomes cupular, 0.4–0.5 mm diam.; bracteoles caducous or persistent, elliptic, membranous, 7–7.4 × 1.8–1.9 mm, with glandular trichomes cupular, 0.27–0.34 mm diam. Calyx green, drying brown, campanulate, 5-lobed, coriaceous, 9.7–10.2 × 4.5–7.7 mm, puberulent and lepidote, with eglandular trichomes simple, with glandular trichomes cupular, 4–7 × 0.46–1.1 mm diam. Corolla orange, tubular, membranous, 43.7–47.7 mm long, tube 30.7–33.9 mm long, 13.2–23.4 mm of max width, 3.8–4.4 mm of width at the base, 7.1–12.2 mm of width at the mouth, puberulent, with eglandular trichomes simple, without nectar guides, lobes orbicular, lobe central inferior 12.4 × 7.3 mm, lobe lateral inferior 11.2 × 8 mm, lobe superior 11.3 × 8 mm. Androecium inserted at ca. 12.1 mm, shorter filaments 36.9 mm long, longer filaments 41.8 mm long, staminode 3.4–3.5 mm long, puberulent to glabrous, hirsute at insertion, with eglandular trichomes simple and glandular trichomes stipitate, anthers pale yellow, curved forward, 3.4–4.4 × 0.6–1.1 mm, exerted. Gynoecium 43.1–44 mm long, ovary cylindrical, 2.6–3 × 0.9–1.1 mm, lepidote, with glandular trichomes cupular at the apex, style 38.3–38.7 mm long, puberulent to glabrous, stigma lanceolate, 1.8–2.7 × 1–1.4 mm, exerted. Fruit green, oblong, inflated, rugose, 130.9 × 30.3 mm, puberulent and lepidote, with eglandular trichomes simple, with glandular trichomes cupular, 0.38–0.65 mm of diameter. Seeds numerous, not-winged, seed body 17.3 × 21.1 × 9 mm.

Etymology: —The species epithet refers to the linear leaflets. Habitat and distribution: — Adenocalymma lineare is only known from three populations from the Espírito Santo state, Brazil ( Fig. 3 ), where these populations are separated from each other by ca. 16 km distance. This species is found between 173–300 m alt. in seasonally semi-deciduous Atlantic forest fragments surrounded by inselbergs.

IUCN red list category: — Adenocalymma lineare is here considered as critically endangered [CR B1ab(iii, iv)] according to IUCN criteria ( IUCN 2012; IUCN Standards and Petitions Subcommittee 2014). The small extent of

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occurrence (42.173 km), reduced number of locations, habitat decline and number of locations of occurrence justify the critically endangered category.

Phenology: —Flowering specimens were collected in March and April. A single fruiting specimen was collected in July.

Morphological discussion: — Adenocalymma lineare , and A. nervosum are understory shrubs from semi-deciduous Atlantic Forest. These species differ from other Adenocalymma species by the linear leaflets, an uncommon feature in tribe Bignonieae . Adenocalymma lineare and A. nervosum are quite similar vegetatively, but differ in habit, prophyll morphology and venation pattern. Besides that, the most striking differences between these two species are in reproductive traits, especially the corolla color and morphology, and the position of anthers and stigma ( Table 1). Adenocalymma lineare is most likely bird pollinated mainly due to the orange and tubular corolla, and the exserted stamens and stigma. Several other species of Adenocalymma from the Atlantic Forest share a similar flower morphology.

Additional material examined: — BRAZIL. Espírito Santo: Águia Branca, Assentamento 16 de Abril, 197 m, 18º54’9.72’’S, 40º44’10.54’’W, 15 March 2006, Demuner V. et al. 1940 (fl) ( MBML) ; Águia Branca, Propriedade do Seu Voito , 300–330 m, 18º54’10’’S, 40º40’01’’W, Magnano L. F. S. et al. 1158 (fr) ( MBML, SPF) ; Águia Branca, saída da estrada Isaías Cotelletti, 173 m, 19º00’23.1’’S, 40º46’48.5’’W, 6 November 2013, Fonseca L. H. M. & Medeiros B. 247 (st) ( SPF) ; Águia Branca, Assentamento 16 de Abril, 197 m, 18º54’9.72’’S, 40º44’10.54’’W, 21 March 2015, Fonseca L. H. M. & Gomes B. M. 426 (fl) ( SPF) ; Águia Branca, Assentamento 16 de Abril, 197 m, 18º54’9.72’’S, 40º44’10.54’’W, 21 March 2015, Fonseca L. H. M. & Gomes B. M. 427 (fl) ( SPF) ; Águia Branca, Assentamento 20 de Abril, 197 m, 18º54’9.72’’S, 40º44’10.54’’W, 21 March 2015, Fonseca L. H. M. & Gomes B. M. 430 (fl) ( 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 2. Adenocalymma lineare. A. Flowering branch. B. Detail of interpetiolar region showing prophylls of the axillary buds. C. Flower bud. D. Floral bract. E. Bracteole. F.Side view of an open flower. G. Calyx artificially cut on one side and spread open. H. Frontal view of the corolla. I. Corolla artificially cut on one side and spread open. J. Nectar disk, ovary, style and stigma. K. Detail of stigma. L. Side view of a fruit. M. Seeds. Illustrated from [A–K] Fonseca L.H.M. & Gomes B.M. 429 (SPF) and [L–M] Magnano L.F.S. et al. 1158 (SPF).

FIGURE 3. Distribution of Adenocalymma lineare and A. nervosum in the Brazilian Atlantic Forest.