Brunellia hippocrepiformis C.I.Orozco & A.J.Pérez, 2020

Orozco, Clara Inés, Pérez, Álvaro J., Romoleroux, Katya, Bohórquezosorio, Andrés Felipe & Aldana, José Murillo, 2020, Three new species of the Andean genus Brunellia (Brunelliaceae) from Colombia and Ecuador, Phytotaxa 433 (1), pp. 27-40 : 36-38

3. Brunellia hippocrepiformis C.I.Orozco & A.J.Pérez sp. nov. ( Figs. 2 , 8 , 9 )

Type: ― ECUADOR. Esmeraldas Imbabura: Reserva Ecológica Cotacachi–Cayapas, comunidad de Piñan, Cordillera de Los Cayapas, sendero de Eloy Alfaro, entrando por Cayapa-Chupa , 3000–3100 m, 00°33’09”N 78°30’03”W, 12 September 2017, A. J. Pérez et al. 11226 (holotype: QCA! –2 sheets, flowers and fruits; isotype: COL! –2 sheets) .

Diagnosis:― Brunellia hippocrepiformis differs from all other species of the genus for the combination of the following characters: the coriaceous, glabrescent and simple leaves, with plane alveolar reticulation, the thickened and glabrous stipules, the irregular insertion of the petiole at the node of one of the three leaves, the inconspicuous 2–serrate margin, the absence of bristly hairs on the fruits, the thickened and rotated fruit pedicel and the 2 follicles that form a horseshoe shape when ripening.

Description:― Tree, up to 12 m tall. Stem with young branches notably angulate, furrowed in dry material, usually glabrous, but also with some scattered and strigose trichomes, internodes 3.0– 5.7 cm long. Stipules geminate, subulate, 2.5–4.0 mm long, with a small and intermediate stipule between the largest ones, the scars of the stipules raised, 1 mm in diameter. Leaves three per node, petiolate, simple, apparently without stipels; petiole yellowish in fresh material (brown and red in dried material), longitudinally striated, 1.7–2.9 cm long, of variable size at the same node; blade lanceolate, 14–22 × 5–8 cm, coriaceous, the adaxial surface bullate, dark-green, shiny, the abaxial surface glaucous (both surfaces yellowish-green in dried material); young leaves pilose, with long and appressed trichomes, which are precociously lost; base cuneate, shortly decurrent; apex acute; margin thickened, usually 2–serrate, the teeth mucronate, the middle tooth less visible; secondary veins in 19–22 pairs, diverging at a 40°, ascending, impressed on the adaxial surface, raised on the abaxial side, the midvein scarcely raised, the veins yellowish abaxially in fresh material (yellow or reddish-brown in dry material), the reticulum plane, the perpendicular tertiary veins well marked. Inflorescence axillary, thyrsoid, 12–17 × ca. 8 cm, bracteate, pedunculate, 3–branched, distally ending in monochasial branches, pilose and glossy; flowered part of the inflorescence 40–50% of total length. Bracts laminar, ca. 2 × 1 mm; peduncle angled, the base decurrent on the stem, ca. 5 mm wide, light green in fresh, reddish brown and furrowed when dry, 6–8 cm long. Flowers actinomorphic to slightly zygomorphic, pentamerous, unisexual, pedicellate, bracteolate; floral buds globose, ca. 2 mm in diameter; pedicel articulation with the inflorescence visibly thickened, the thickened and terete pedicel slightly rotated to hold the fruits, 3–4 × 1 mm, yellowish-green, sometimes with brown in fresh material, smoothly angled in dry material; bracteoles deciduous, inconspicuous, linear, ca. 1 mm long; calyx with 5 sepals, 9–10 mm in diameter, sepals usually ovate and coriaceous, 3.2–4.0 × 2–3 mm, joined by a short and wide tube, the tube ca. 1 mm long, with short, stiff and appressed hairs; corolla absent. Staminodes 10, filaments 1–1.5 mm long, anthers ca. 0.5 mm long. Ovary with 4–5 carpels, not all developed as fruits, carpels 3–6 × 1–3 mm, inserted on the disk, the disk ca. 4 mm in diameter, surrounded by golden yellow and dense trichomes. Fruits 7–10 × 3.2–4.0 mm, covered by dense and thick hairs, bristly trichomes absent, the two largest follicles oriented in a horseshoe-shape due to the pedicel rotation, an aborted carpel usually present between the two most mature follicles; calyx in fruit 10–12 mm in diameter, the endocarp boat-shaped, 6–9 × 3.0– 3.5 mm; seeds 2, ellipsoid, ca. 2 × 1 mm, red and shiny.

Etymology: ―The specific epithet refers to the horseshoe shape of the fruit.

Habitat and distribution:― Brunellia hippocrepiformis is endemic to Ecuador, in Cotacachi-Cayapas Ecological Reserve of Esmeraldas and Imbabura Provinces. The habitat is a hyper-humid and cloudy area of the northwestern slope of the Ecuadorian Andean Cordillera at 3000–3100 m of elevation. According to the Ministerio del Ambiente de Ecuador (2013), this locality lies within the montane evergreen forest belt of the Western Cordillera of the Ecuadorian Andes ( Fig. 2 ). It belongs to the Choco biogeographic region, where the new species is sympatric with B. tomentosa Bonpland (1808: 214) .

Phenology:―The known individuals produced flowers and fruits in September.

Conservation status:―This new species is only known from one collection. Its discovery in a reserve guarantees its conservation, since it is included in the system of protected areas of Ecuador, considered as a hotspot of biodiversity. Assessment of IUCN categorization is not provided for this species due to deficient data (DD).

Observations:― Brunellia hippocrepiformis might be included in subsect. Simplicifoliae or at least in sect. Simplicifolia , on account of its simple leaves. However, according to recent molecular data (Murillo et al. in prep.), its current position is uncertain. In addition, as said above, this species is morphologically very different from any other Brunellia .

Figures

FIGURE 2. Distribution map.A. Brunellia alnifolia in Colombia. B. Brunellia hippocrepiformis in Ecuador.

FIGURE 8. Brunellia hippocrepiformis.A. Fruiting branch. B. Stipule scars. C. Stipules. D. Margin in abaxial view. E. Bullate surface of the leaves, margin and adaxial reticulation of the veins. F. Reticulation of the veins in the abaxial side of the leaves. G. Abaxial indument in the young leaf. H. Branching of the infructescence. I. Fragment of the inflorescence, bracts and bracteoles. J. Floral buds K. Maturing follicles. L. The two largest follicles in a horseshoe-shape. M. One of the largest follicles. N. Follicle opens by its ventral suture (the seeds are attached by their funiculus to the boat-shaped endocarp). Drawing by Marcela Morales.

FIGURE 9. Brunellia hippocrepiformis. A. Fruiting branch (notice the uneven insertion of the petiole on the stem). B. Immature follicles, staminodes. C. Infructescence (the two large follicles form a horseshoe by the rotation of the fruit pedicel with the two largest follicles). (Photographs by A. J. Pérez).