Ameroglossum xukuruorum E.M.Almeida, Christenh. & 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 : 20-21

Ameroglossum xukuruorum E.M.Almeida, Christenh. & L.P.Felix sp. nov.

urn:lsid:ipni.org:names:77216331-1

Figs 2I , 5i–k

Diagnosis

Ameroglossum xukuruorum sp. nov. is similar to A. pernambucense in having verticillate leaves and involute lobes on the lower lip. It differs by its glabrous or glabrescent vegetative portions (vs villose) and usually lanceolate leaf blade with sparsely branched venation (vs elliptic to narrowly elliptic and densely branched venation).

Etymology

The specific epithet is dedicated to the Amerindian Xukuru people, because the type material was collected with their assistance on tribal lands in the Serra do Ororubá Range.

Material examined

Type BRAZIL – Pernambuco • Pesqueira, Serra do Ororubá , Reserva Indígena Xukuru de Cimbres ; 08°19ʹ15ʺ S, 36°46ʹ12ʺ W; 1122 m a.s.l.; 30 Jun. 2015; L.P. Felix et al. 15647; holotype: EAN!; isotypes: IPA!, K!, RB!, UFP!.

Paratypes BRAZIL – Paraíba • São João do Tigre, Serra do Paulo ; 08°05ʹ35ʺ S, 36°40ʹ35ʺ W; 1193 m a.s.l.; 16 Jul. 2010; L.P. Felix & L.I.F. Alves 13085; EAN[16,438] ! • ibid.; 23 Aug. 2013; L.P. Felix 14318; EAN[19,895] ! • ibid.; 3 Aug. 2011; S. Nascimento 105; EAN[18,513] ! • Serra do Enjeitado ; 4 Aug. 2011; S. Nascimento 168; EAN[18,173] ! • Serra do Paulo ; 08°05ʹ36ʺ S, 36°38ʹ34ʺ W; 1094 m a.s.l.; 4 Aug. 2011; S. Nascimento 151; EAN[18,555] ! – Pernambuco • Pesqueira, Serra do Ororobá ; 2 Aug. 1979; D. de Andrade-Lima et al. 79-9,659; IPA[46,742] ! • Serra do Gavião ; ± 800 m a.s.l.; 19 Jun. 2005; M. Oliveira 1,817; UFP[41,495] ! • Jataúba, Sítio Sobrado ; 08°04ʹ53ʺ S, 36°34ʹ48ʺ W; 1021 m a.s.l.; 6 Jun. 2016; E.M. Almeida, L.I.F. Alves & J.A.L. Neves 1673; EAN[24,603] !.

Description

Saxicolous chamaephyte up to 80 cm, occasionally with some secondary branching at the branch tips. Young branches slightly purplish, dull, slightly angular, often narrowly winged, covered by inconspicuous papillose trichomes; mature branches cinereous, slightly inclined to decumbent, cylindrical. Leaves verticillate with usually four leaves per node; leaf blade 2.5–8.2 × 0.5–1.4 cm, green, cinereous, lustrous, narrowly elliptic to lanceolate, sometimes elliptic, bullate; adaxial side glabrous; abaxial side glabrous to glabrescent, with trichomes aciculate and/or papillose; apex acute to acuminate, recurved; margin revolute when young, later flat to revolute; glabrous. Inflorescences in simple dichasia, frequently unifloral. Peduncle slightly purplish to green, cylindrical, glabrous; primary peduncle 0.25– 1.10 × 0.05–0.08 cm, secondary 0.2–0.3 × 0.7 cm. Pedicel 0.3–0.5 × 0.1 cm, slightly purplish to green, glabrous; ventral side without wings. Bracts 0.10–0.30 × 0.05 cm, purplish to green, glabrous. Calyx slightly purplish to green, glabrous; sepals lanceolate, dorsal one 0.75–1.10 × 0.10–0.20 cm, lateral ones 0.60–1.00 × 0.15–0.20 cm, ventral ones 0.60–1.00 × 0.10–0.25 cm. Corolla 2.5–3.4 cm, adaxial portion orange-red, ventral portion and proximal third yellow, base wide, glabrous; tube 2–3 cm; upper lip 0.55–0.75 × 0.06–0.10 cm, bilobate; lower lip, inner perianth with trichomes conical, yellowish white; lobes involute, median lobe 0.15 × 0.04 cm. Stamens exserted, adnate at the median third of the corolla tube; filaments white, 1.8–3.5 cm long; thecae ca 0.15 cm diam.; staminodium ca 0.3 cm, adnate at the proximal third of the corolla tube, glabrescent, with short-glandular trichomes, rarely papillose. Ovary 0.40–0.50 × 0.15–0.30 cm; style 2.4–3.3 cm, exserted, glabrous. Capsule 0.9–1.0 × 0.3–0.5 cm, green to slightly purplish. Seeds 0.10 × 0.05 cm.

Distribution

Ameroglossum xukuruorum sp. nov. has only been collected above 1000 m a.s.l., which corresponds to the highest areas of the Borborema Plateau in the states of Paraíba (São João do Tigre in the Cariri Ocidental microregion) and Pernambuco (Pesqueira in the Vale do Ipojuca microregion). Elevation between (800–)1000 and 1200 m.

Ecology

Ameroglossum xukuruorum sp. nov. appears to prefer higher elevation habitats. It was encountered flowering and fruiting between April and August and is pollinated by hummingbirds (pers. obs.).

Population and threats

Ameroglossum xukuruorum sp. nov. is restricted to the municipalities of Jataúba, Pesqueira and São João do Tigre and has been collected in the Xukuru Indigenous Reserve on a rock outcrop covering approximately 50 ha, with a population of more than 100 individual adult plants. Additionally, the Serra do Ororubá Range, where the reserve is located, has a series of granite outcrops that are difficult to access, and it is possible that other populations of A. xukuruorum sp. nov. (or other species of Ameroglossum ) are yet to be discovered there. The two known locations in Paraíba State have a total of ca 100 adult individuals. The isolated populations are exposed to burning and trampling by livestock.

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.