Ameroglossum intermedium E.M.Almeida, A.M.Wanderley & L.P.Felix, 2021

Almeida, Erton M., Christenhusz, Maarten J. M., Wanderley, Artur Maia, Cordeiro, Joel Maciel P., Melo, José Iranildo Miranda De, Batista, Fabiane Rabelo Da Costa & Felix, Leonardo P., 2021, An overview of the Brazilian inselberg genus Ameroglossum (Linderniaceae, Lamiales), with the description of seven new species, European Journal of Taxonomy 746, pp. 1-25 : 16-17

Ameroglossum intermedium E.M.Almeida, A.M.Wanderley & L.P.Felix sp. nov.

urn:lsid:ipni.org:names:77216330-1

Figs 2F , 5e–h

Diagnosis

Ameroglossum intermedium sp. nov. combines characters of both A. manoelfelixii and A. pernambucense . It can be distinguished from A. manoelfelixii by its puberulent branches and leaves (vs glabrousglabrescent leaves), with acicular trichomes recurved at the apex (vs papillose trichomes), and from A. pernambucense by its compound dichasial inflorescence (vs a simple dichasium) and the revolute lower lip (vs involute).

Etymology

The specific epithet is derived from the Latin adjectives ʻ inter ʼ, ʻbetweenʼ, and ʻ medius ʼ, ʻmiddleʼ, referring to the morphological characteristics of the new species that are intermediate between A. manoelfelixii and A. pernambucense .

Material examined

Type BRAZIL – Alagoas • Quebrangulo ; 09°18′17″ S, 36°31′13″W; 502 m a.s.l.; 23Aug. 2012; E.M.Almeida & A.M. Wanderley 478; holotype: EAN!; isotypes: IMA!, IPA!, K!, RB !.

Other material

BRAZIL – Alagoas • Quebrangulo, estrada para Bom Retiro; 09°17ʹ56ʺ S, 36°30ʹ33ʺ W; 25 Aug. 2013; L.P. Felix & E.M. Almeida 14,339; EAN[19,860] !.

Description

Saxicolous chamaephyte up to 150 cm, frequently with secondary branching along the stem. Young branches green to slightly purplish, bifacial, dull, quadrangular or hexangular, often narrowly winged, pubescent, with recurved trichomes; brown cinereous when mature, slightly inclined to decumbent, subquadrangular. Leaves opposite, decussate, occasionally verticillate and then up to three leaves per node; leaf blade 5.1–14.0 × 1.4–3.9 cm, green, lustrous, elliptic to narrowly elliptic, rarely trullate, bullate when young, later smooth; adaxial side glabrous, abaxial side pubescent, with recurved trichomes; apex acute, rarely acuminate, flat to reflexed; margin revolute when young, later flat, ciliate. Inflorescence a compound dichasium, occasionally simple. Peduncle green or tinged purple, subcylindrical, winged, pubescent, with recurved trichomes; primary peduncle 0.7–4.0 × 0.1–0.2 cm, secondary peduncle 0.30– 1.80 × 0.13–0.15 cm, tertiary peduncle 0.30–1.20 × 0.07–0.10 cm. Pedicel 0.6–2.5 × 0.1–0.2 cm, green to slightly purplish, pubescent, with recurved trichomes; ventral side winged up to the proximal third. Bracts 0.20–0.60 × 0.03–0.08 cm, green, abaxial side glabrous, adaxial side glabrescent with papillose trichomes, margin ciliate with recurved trichomes. Calyx green, abaxial side glabrescent, with recurved and/or papillose trichomes, adaxial side covered by papillose trichomes, margin ciliate with recurved trichomes; sepals lanceolate, dorsal one 1.2–1.5 × 0.3–0.5 cm, lateral ones 1.0–1.2 × 0.2 cm, ventral ones 0.8–1.1 × 0.2–0.3 cm. Corolla 4.5–5.6 cm long, orangish, with proximal third yellowish, external side pubescent, trichomes glandular, rarely recurved and/or papillose; tube 3.5–4.4 cm long; upper lip 1.2–1.8 × 0.6–0.8 cm, slightly bilobate; lower lip 1.1–1.4 × 0.35–0.50 cm, inner perianth with white filiform trichomes; lobes revolute, median lobe 0.1 × 0.2 cm. Stamens occasionally with the ventral pair exserted, adnate to the median third of the corolla tube; filaments violet, dorsal ones 1.6–2.6 × 0.8 cm, ventral ones 1.9–2.9 × 0.8 cm; thecae ca 0.2 cm diam.; staminodium 0.3–0.4 cm, adnate to the median third of the corolla tube, glabrous. Ovary 0.4–0.7 × 0.2–0.3 cm; style 3.6–5.6 cm, occasionally exserted. Capsule 1.2–1.6 × 0.6–0.8 cm, greenish. Seeds 0.10 × 0.05 cm.

Distribution

Only two populations of Ameroglossum intermedium sp. nov. are currently known, both in the municipality of Quebrangulo, Agreste mesoregion of Alagoas State. Elevation ca 500 m.

Ecology

This species occurs exclusively on granite outcrops. Flowering and fruiting recorded in August and like all other Ameroglossum species it is pollinated by hummingbirds. The surrounding vegetation was probably originally composed of deciduous forest, but this has now been replaced by natural pasture.

Population and threats

Only two rock outcrops separated by pasture in a single municipality in Alagoas State are known to harbour this species. Approximately 200 adult individuals can be found in the first population, whereas the other comprises approximately 30 individuals. The main threat to these populations are farming and grazing of the site by stray animals.

Taxonomic notes

Among the species of Ameroglossum with quadrangular stems, A. intermedium sp. nov. stands out by having reproductive and vegetative structures covered in trichomes, a characteristic otherwise typically observed in A. pernambucense . However, A. intermedium sp. nov. differs by having leaves that are principally opposite and decussate, inflorescences of compound dichasia and the revolute lower lip.

Figures

Fig. 2. Reproductive branches and floral details of different taxa of the genus Ameroglossum Eb.Fisch., S.Vogel & A.V.Lopes. A. A. alatum sp. nov. B. A. asperifolium sp. nov. C. A. bicolor sp. nov. D. A. fulniorum sp. nov. E. A. genaroanum sp. nov. F. A. intermedium sp. nov. G. A. manoelfelixii L.P.Felix & E.M.Almeida. H. A. pernambucense Eb.Fisch., S.Vogel & A.V.Lopes. I. A. xukuruorum sp. nov.

Fig. 5. a–d. Ameroglossum genaroanum sp. nov. (Almeida et al. 397). a. Reproductive branches. b. Inflorescence. c. Flower. d. Corolla opened, showing the stamens. e–h. Ameroglossum intermedium sp. nov. (Almeida & Wanderley 478). e. Reproductive branches. f. Inflorescence. g. Flower. h. Corolla opened, showing the stamens. i–k. Ameroglossum xukuruorum sp. nov. (Felix et al. 15647). i. Reproductive branches. j. Flower. k. Corolla opened, showing the stamens.