Tynanthus macranthus Williams (1967: 250)

Medeiros, Maria Cláudia Melo Pacheco De & Lohmann, Lúcia G., 2015, Taxonomic Revision of Tynanthus (Bignonieae, Bignoniaceae), Phytotaxa 216 (1), pp. 448-450 : 448-450

8. Tynanthus macranthus Williams (1967: 250) (as “ Tynnanthus ”). Type:— COSTA RICA. Heredia: Roadside 8 km south of San Miguel , 9 July 1964, R.W. Lent 42 (holotype F! (1622130); isotypes NY! (barcode 328981), OKL! (barcode 01 0097215) photo, US! (barcode 125787)).

Fig. 11 : F–K

Lianas. Branchlets terete, without ritidome, finely striated, densely lenticeled, densely puberulent, with simple and peltate trichomes; interpetiolar ridge absent or present; interpetiolar patelliform glands present; prophylls of the axillary buds 1–3 mm long, 1–2.5 mm wide, minute, shallowly triangular, densely puberulent throughout, with simple and peltate trichomes. Leaves 2 foliolated; terminal leaflets often modified into simple tendrils, without adhesive-disks on tip; petioles and petiolules densely puberulent throughout surface, with simple, peltate and patelliform trichomes; petioles (0.6–) 0.8–2.3 cm long; petiolules (0.3–) 0.7–2 cm long; leaflets (2.6–) 4.5–14.9 cm long, (1–) 2.7–6.4 cm wide, chartaceous to coriaceous, discolor, elliptic; apex acuminate, mucronate; base cuneate or obtuse, symmetrical; margin entire; the abaxial surface densely puberulent to puberulent throughout (sometimes only on and near the veins), with simple, peltate and patelliform trichomes; the adaxial surface puberulent to glabrescent on and near the veins, with simple and peltate trichomes; glandular trichomes distributed especially on the abaxial surface; second venation weak brochidodromous; pocket domatia with or without trichomes. Inflorescence axilar or terminal, a thyrse, dense, with corymbose or subcorymbose aspect, 2.5–3– 6 cm long; axis densely puberulent, with simple and peltate trichomes; bracts of the inflorescence predominantly caducous, densely puberulent throughout, 1–2 mm long; floral bracts 0.8–1.2 mm long; floral pedicels 2–6 mm long. Calyx

28 • Phytotaxa 216 (1) © 2015 Magnolia Press

MEDEIROS & LOHMANN green, 5–9(–10) mm long, 4–5 mm wide, with transversal aperture, minutely 5-denticulate (sometimes truncate), densely puberulent throughout outside, without patelliform glands; lobes 0.2–0.5 mm long. Corolla white, 2–3.8 cm long, 2.5–4 mm wide at the tube opening; tube 5–11 mm long, internally tomentose at the base, with simple and long and short stipitate trichomes; nectar guides present, yellow; lobes densely pubescent to pubescent throughout lower ones and at the margin of (sometimes throughout) upper ones; upper ones 2–8 mm long, 1.5–4 mm wide, obtuse to rounded (sometimes acute); lower ones 4–8(–10) mm long, 3–7 mm wide, obtuse to rounded. Androecium with fertile stamens inserted ca. 3 mm from the base of the corolla; shorter ones 7–13 mm long; longer ones 9–18 mm long; anthers thecae 1.7–2.5 mm long, elliptic, inserted; connective extending 0.2–0.4 mm beyond anther attachment; staminode 4–7 mm long, glabrescent, with long and short stipitate trichomes. Gynoecium 14–22 mm long; ovary 1.8–2.5 mm long, 0.9–1.1 mm wide, conical to oblong, densely pubescent; style 12–19 mm long, densely pubescent throughout. Fruit not seen. Seeds not seen.

Phenology: —Flowers from April to November; the fruiting season is unknown.

Distribution and habitat: —Occurs in moist broadleaf forests from Costa Rica (Heredia and Limón) and Panama (Veraguas) ( Fig. 13 ).

Additional specimens examined: — COSTA RICA. Heredia: Entre San Miguel y Cariblanco de Sarapiqui, 725 m, 10 July 1964, A . Jiménez M . 2044 (F photo, NY). Limón: Talamanca, Between Cahuita and the oil drilling platforms beyond Suretka , 100–300 m, 23–25 April 1982, K . Barringer et al. 2671 ( F, MO) . PANAMA. Veraguas: Vicinity of Continental Divide, third branch of Rio Santa Maria to drop-off to lowlands, 12–15 km NW of Santa Fe, 650–750 m, 16–17 November 1974, R . Dressler 4846 ( MO). NW of Santa Fe, 8.8 km from Escuela Agricola Alto de Piedra , 17 May 1975, R . Dressler et al. 6191 ( MO, US).

Taxonomic notes: — Tynanthus macranthus is easily distinguished from the other species of the genus by the large flowers (2–3.8 cm), with conspicuously bilabiate corolla due to the short corolla tube (0.5–1.1 cm). Apart from that, T. macranthus is also characterized by the densely puberulent branchlets, simple tendrils, interpetiolar patelliform glands and corymbose to subcorymbose inflorescences. Tynanthus macranthus was the first species to diverge in Tynanthus ( Medeiros & Lohmann 2015) and is sister to the remaining species of the genus.

TAXONOMIC REVISION OF TYNANTHUS (BIGNONIEAE)

Figures

FIGURE 11. A–E. Tynanthus labiatus: A. Flowering branch; B. Petiolar region showing minute prophylls of the axillary buds; C. Detail of inflorescence axis showing the indumentum and bracts; D. Flower; E. Fruit (J.R. Pirani 3900, SPF). F–K. T. macranthus: F. Flowering branch; G. Detail of the densely pubescent indumentum in branchlet; H. Interpetiolar glands (R. Lent 42, NY isotype); I. Flower; J. Open corolla showing the androecium; K. Open calyx showing the gynoecium (A. Jiménez M. 2044, NY). Illustration by Klei Sousa.

FIGURE 13. Distribution of Tynanthus macranthus.