Martinella insignis A.H. Gentry ex Zuntini & L.G. Lohmann, 2014

Zuntini, Alexandre R. & Lohmann, Lucia G., 2014, Synopsis of Martinella Baill. (Bignonieae, Bignoniaceae), with the description of a new species from the Atlantic Forest of Brazil, PhytoKeys 37, pp. 15-24 : 17-19

1. Martinella insignis A.H. Gentry ex Zuntini & L.G. Lohmann sp. nov. Figs 1 -2

Type.

BRAZIL. Bahia: Itamaraju, Rodovia Itamarajú-Teixeira de Freitas, 3km de Itamaraju (BR-101). Fazenda Chapadão, 3 November 1983, R. Callejas, A. M de Carvalho & L. M. Silva 1629 (holotype MBM-94960!; isotypes CEPEC not seen, MO- 3600686!, NY-00483568!, RB-232556!).

Diagnosis.

Martinella insignis differs from Martinella iquitoensis and Martinella obovata by its 5-lobed calyces and yellow corollas, in contrast to 2-4-lobed calyces and dark purple to red corollas in these other species ( Table 1 ).

Description.

Lianas. Branches green, drying brownish, striated, densely covered with stipitate-glandular trichomes when young; prophylls 0.7-1.5 × 1.0 mm, densely covered with stipitate glandular trichomes, without patelliform glands (with few patelliform glands). Leaves 2-foliolate with the terminal leaflet generally modified into a trifid tendril; petioles terete, 34-64 mm long, covered with stipitate glandular trichomes; petiolules terete, 14-42 mm long, covered with stipitate glandular trichomes; leaflets weakly discolorous, membranous, ovate, with a long acuminate to caudate apex and a cordate base, margins entire (sinuate), 7.6-11.8 × 3.4-6.4 cm, glabrous except on margins and main veins of the abaxial surface where stipitate glandular trichomes are found, with pocket domatia on the axils of primary and secondary veins, with few glands concentrated near base and scattered along the mid-vein on the adaxial surface. Inflorescences compound dichasia, with up to 7 branching orders, 9.2-12.3 cm long, sparsely to densely covered with stipitate glandular trichomes; bracts linear to narrowly elliptic, 8.4-24.7 × 0.8-3.4 mm, densely covered with stipitate glandular trichomes; pedicels terete, 5.8-19.4 mm, sparsely to densely covered with stipitate glandular trichomes. Flowers with calyx pale green, tubular (campanulate), 8.8-15.4 × 6.5-12 mm, sparsely covered with stipitate glandular trichomes except densely covered at the base, with few glands near the apex; lobes 5, very shallowly triangular, aristate, aristae 2.9-8.6 mm long, densely covered with stipitate glandular trichomes; corolla yellow, weakly curved, 29.5-48.3 mm long, tubular basal portion 12.7-18.9 long × 2.4-4.5 mm wide, upper campanulate portion 15.0-23.4 long × 9.2-17.2 mm wide, lobes subcircular, 3.8-9.8 × 6.1-10.9 mm, with ciliate margins; stamens in two lengths, longer ones 11.4-17.3 mm, shorter ones 12.1-15.8 mm, thecae 2.4-3.0 mm, glabrous; staminode 1.1-3.6 mm, glabrous; gynoecium 29.2-39.6 mm long; ovary glabrous; style glabrous; stigma rhomboid, glabrous; nectariferous disk 2.3-3.0 × 1.0-1.8 mm. Capsules 33.6-73.0 × 1.1-1.2 cm, pubescent when immature, glabrous when developed. Seeds ca. 1.0 × 4.6 cm.

Distribution and habitat.

Martinella insignis is restricted to the northern portion of the Brazilian Atlantic Forest, occurring predominantly in areas with sandy soils ( Fig. 3 ).

Etymology.

The species epithet means remarkable or clearly distinguishable. This epithet was probably selected by Alwyn Gentry as reference to the contrasting floral color among species of Martinella .

Phenology.

Flowering specimens were collected between September and February and fruiting collections in January, September and November.

Conservation status.

This species is considered Data Deficient [DD] according to IUCN Standards and Petitions Subcommittee (2014) since this taxon is only known from very few specimens, with little information about its distribution and abundance. Further field studies are needed so that its conservation status can be properly documented.

Discussion.

Martinella insignis is the first species of Martinella found in the Atlantic Forest of Brazil. This new species clearly belongs to Martinella based on its prophylls, the continuous interpetiolar ridges and the corolla shape. However, Martinella insignis can be distinguished by the membranous leaflets, 5-lobed aristate calyces, and yellow corollas. In addition, Martinella insignis also has pocket-shaped leaf domatia ( Fig. 2C ) and a puberulous indument of glandular stipitate trichomes that covers almost all organs, with variable density ( Fig. 2E-F ). These trichomes may also be found in Martinella obovata and a few other species in Bignonieae , and are typically formed by a multicellular secretory head, supported by a uniseriate stalk ( Nogueira et al 2013). Only corollas and fruits lack these; the corollas are glabrous, and fruits have simple, deciduous trichomes ( Fig. 2G ). Similar to the other species, the root system of Martinella insignis has unusual tuberous portions ( Fig. 2D ) that might represent an adaptation to the sandy soils, by accumulating water. However, the anatomical structure and function of these are yet unknown. Alwyn Gentry had already noted this new taxon, and had proposed the epithet “insignis” in sched.; his earlier findings are here accredited.

Additional collections examined.

Brazil. Bahia: Guaratinga, Fazenda Vitória, 16°43'S, 39°46'W, 29 October 1979, L.A. Mattos Silva & H.S. Brito 634 (CEPEC, MO). Itabuna, Alcobaça para(ramal) S. Antonio, 24 January 1972, R.S. Pinheiro 1759 (CEPEC, MO). Itamaraju, S. Mori, L.A. Mattos Silva & T.S. Santos 10743 (CEPEC, MO), Itamaraju, Fazenda Riacho das Pedras, prop. Sr. Gersino Antônio Bronzon, 17°08'48"S, 39°21'53"W, 12 February 2007, R.A.X. Borges, A. Amorim, W.W. Thomas, L.C. Gomes, S. Sant’Ana & O. Cruz 825 (CEPEC, SPF). Espírito Santo: Linhares, Reserva Natural da Companhia Vale do Rio Doce ("Reserva de Linhares"), MME, 19°07'57.5"S, 40°04'06.3"W, 65m, 14 December 2007, A.R. Zuntini, W.A.A. Pires & G.S. Siqueira 151 (CVRD, RB, SPF), A.R. Zuntini, E. Françoso, J. Lopes & V. Augusto 321 (SPF). Governador Lindenberg, Pedra de Santa Luzia, 420-590 m, 7 November 2007, V. Demuner, T.A. Cruz & R.R. Vervloet 4481 (MBML, SPF). Sooretama, Mata de tabuleiro situada ao Noroeste da sede da Reserva da Sooretama, 14 July 1969, D. Sucre 5519 (RB-photo).

Figures

Figure 1. Morphology of Martinella insignis: A Habit B Node with interpetiolar ridge C Glandular stipitate trichomes D Flower (lateral view) E Calyx (opened) and gynoecium F Fruit G Root system with tuberous portions. From Zuntini 151 (A-E), Sucre 5519 (F) and Zuntini 321 (G).

Figure 2. Details of Martinella insignis: A Flower B Leaflet base showing glands (abaxial face) C Mite-domatia between primary and secondary veins (abaxial side) D Root system with tuberous portions E Calyx detailing the aristae F Arista detail with glandular trichomes G Simple, tector trichomes on immature fruit. From Zuntini 151 (A-C, E, F), Zuntini 321 (D) and Demuner 4481 (G). Micrographs were obtained using focus stacking.

Figure 3. Distribution of Martinella species: Martinella insignis (solid blue circle), Martinella iquitoensis (solid green square) and Martinella obovata (open red triangles). Elevation in meters, according to the scale presented on the right.