Cuphea auriflora Lourteig ex M.G.Facco & T.B.Cavalcanti

Facco, Marlon Garlet & Cavalcanti, Taciana Barbosa, 2023, Taxonomic Revision of Cuphea sect. Trispermum s. l. (Lythraceae), Phytotaxa 588 (1), pp. 1921-1935 : 1921-1935

4. Cuphea auriflora Lourteig ex M.G.Facco & T.B.Cavalcanti , sp. nov.

Type:— BRAZIL. Minas Gerais: Serra do Espinhaço , sandy cerrado immediately north of Gr ã o Mogol, elev. 950 m, 17 February 1969, Irwin, Reis dos Santos, Souza & Fonseca 23426 (holotype NY [00386499] image!, isotypes BR image!, IAN, K image!, P image!, W image!). Figs. 7H–N , 20 .

Diagnosis:— Cuphea auriflora morphologically resembles C. flava , both classified in C. sect. Trispermum s.l., but differs mainly by the narrow-ovate to narrow-elliptic leaves, covered by one-armed cystolithic appressed trichomes on both surfaces, and floral tubes 5–7.2 mm long, covered by short, erect, eglandular trichomes and short glandular trichomes vs. broad-ovate to ovate-oblong, rarely narrow-ovate leaves, usually glandular-ciliate, glabrous on both surfaces, and floral tubes 7–9 mm long, usually glabrous.

Subshrubs 20–80 cm tall; stems erect to decumbent, indumentum pubescent and sparsely glandular, eglandular trichomes <0.5 mm long, erect or with curved apices, glandular trichomes short, <0.5 mm long; internodes 0.5–1.5 cm long; brachyblasts absent. Leaves opposite, rarely 3–5-verticillate, membranaceous to chartaceous, sessile to subsessile, blades 3–17 × 1–6 mm, narrow-ovate to narrow-elliptic, apex acute, base obtuse to subcordate, margin plane to revolute, indumentum strigose on both surfaces, one-armed trichomes, mixed with sparse glandular trichomes; hyphodromous to brochidodromous. Racemes 15–25 cm long, frondose to frondose-bracteose, compound, elongated, indistinct; bracts similar to leaves, subequal pairs. Flowers alternate; pedicels 1.5–2.6 mm long; bracteoles 0.9–1 mm long, ovate to elliptic; floral tubes 5–7.2 mm long; spur obtuse, deflexed; outer surface yellow-green, indumentum pubescent and short-glandular; inner surface villous behind the stamens, pilose on the lower third of the floral tube; petals 6, yellow, subequal, sometimes the dorsal petals slightly smaller than the ventral petals, two dorsal 3.3–3.5 × 1.3 mm, narrow-obovate, four ventral 3.8–4.1 × 1.4–1.5 mm, narrow-obovate; stamens free in the upper third of the floral tube, five antesepalous exserted, four antepetalous subexserted; pistil ca. 4 mm long; ovary glabrous; style sparsely pilose; ovules 3(–5); nectary ca. 0.5 × 0.6 mm, deflexed. Seeds (1–)2–3(–4), ca. 2.1 × 1.9 mm, obovate, apex obtuse to slightly retuse, base slightly acute, margin obtuse.

Phenology: —Collected with flowers and fruits practically all over the year, most intensely from December to April.

Distribution and habitat: — Brazil, in Bahia and Minas Gerais states ( Fig. 20 ); “campos rupestres”, on sandy soils, “campos sujos”, riverbanks, “carrascos” in the Cerrado-Caatinga transition, rarely on roadsides; 700–1300 m elev.

Conservation status: — Cuphea auriflora was categorized as Least Concern (LC) due to its wide geographic distribution.

Etymology: —A. Lourteig in 1971 identified that the collection “ Irwin et al. 23426 ” belonged to a new species, naming it as “ C. auriflora ” in the labels of several herbaria. Since the name was never published, it was decided to keep the specific epithet as a tribute to Lourteig . The specific epithet refers to the yellow color of the flowers.

Paratypes: —BRAZIL. Bahia:Abaíra,6 km de Ouro Verde, na estrada velha para Abaíra, 13º16’00”S, 41º45’00”W, 28 December 1988, Harley et al. 27858 (CEN!, SPF!); Abaíra, Gerais do Pastinho, 13º15’00”S, 41º45’00”W, 31 January 1992, Hind et al. H 51425 (CEN!, HUEFS!, SPF!); Abaíra, entroncamento BA-142-Catolés, km 15, na margem da estrada, 13º16’24”S, 41º44’28”W, 12 August 2016, Facco et al. 494 (CEN!); Caetité, 25 km from Caetité to Brejinho das Ametistas and beyond (i.e.c. 1 km S of Brejinho das Ametistas, near Mineraç ã o), 02 February 1991, Taylor et al. 1532 (CEN!, SPF!); Caetité, arredores de Brejinho das Ametistas, 14º16’00”S, 42º31’28”W, 12 March 1994, Roque et al. CFCR 14967 (CEN!, ESA!, SPF!); Licínio de Almeida, trilha Lameir ã o para o trilho do trem, 14º41’37”S, 42º32’07”W, 22 February 2014, Roque et al. 4187 (ALCB!, UEC image!); Piat ã, estrada Piat ã -Abaíra, 4 km após Piat ã, 13º09’00”S, 41º47’00”W, 07 January 1992, Harley et al. 50683 (CEN!, HUEFS!, SPF!); Piat ã, estrada para Catolés, lado esquerdo da estrada, 08 January 1999, Cavalcanti et al. 2449 (CEN!); Seabra, ca. 24 km N of Seabra, road to Água de Rega, 25 February 1971, Irwin et al. 31050 (NY image!, UB!). Minas Gerais: Gr ã o Mogol, Vale do Rio Itacambiruçu, entre a Fazenda Jambeiro e estrada para Cristália, 26 February 1986, Cavalcanti et al. CFCR 9682 (CEN!, UEC image!, SPF!); Gr ã o Mogol, estrada para Gr ã o Mogol, na borda do Parque Estadual Gr ã o Mogol, 16º36’33”S, 42º56’22”W, 09 December 2011, Zanatta et al. 1097 (CEN!, UB!); Gr ã o Mogol, estrada vicinal ca. 5 km da rodovia para Gr ã o Mogol, 16º35’45”S, 42º55’38”W, 03 February 2015, Cavalcanti et al. 3895 (CEN!); Itacambira, entroncamento BR-367-Itacambira, 15 km do entroncamento, 17º15’00”S, 43º05’13”W, 05 February 2015, Cavalcanti et al. 3903 (CEN!); Salinas, Sítio 6-Ponto 5 (Projeto Bem Diverso), 16º07’05”S, 41º52’24”W, 04 December 2016, Sevilha et al. 6184 (CEN!).

Cuphea auriflora is a subshrub with yellow flowers ( Fig. 7J ), described here based on specimens collected above 700 m elevation, in the Espinhaço mountain range, from central Bahia state to northern Minas Gerais ( Fig. 20 ). These specimens were initially identified as C. brachiata , a species morphologically similar to C. flava . The analysis of type materials, protologues and herbarium collections confirmed that C. brachiata and C. flava are found only on the coast of Brazil, in “restinga” vegetation. The new molecular phylogeny of Cuphea in progress (Cavalcanti, pers. comm.) showed that, in the Trispermum clade, the yellow-flowered specimens from the Espinhaço Range are genetically distant from the C. brachiata / C. flava specimens from the Brazilian coast, the latter lacking support for separation. The preliminary results of this molecular phylogeny, and morphological analyses performed here, provide support for the description of the new species, C. auriflora , and the synonymization of C. brachiata under the oldest name, C. flava .

Cuphea auriflora is recognized by its narrow-ovate to narrow-elliptic leaves, strigose on both surfaces, and floral tubes 5–7.2 mm long, pubescent and short-glandular. While C. flava has broad-ovate leaves, rarely narrow or oblong, glabrous, with a glandular-ciliate margin, and floral tubes 7–9 mm long, usually glabrous.

Figures

FIGURE 7. A–G. Cuphea araguaiaensis. A. Habit; B. Detail of a branch with brachyblasts; C. Abaxial surface of the leaf, with strongly revolute margins; D. Floral tube in lateral view, without petals; E. Floral tube in longitudinal-dorsal section, without petals; F. Pistil; G. Seed. H–N. Cuphea auriflora. H. Habit; I. Flowering branch; J. Flower in frontal view; K. Floral tube in lateral view, without petals; L. Floral tube in longitudinal-dorsal section, without petals; M. Pistil; N. Seed.A–F: Pereira-Silva et al. 17010; G: Macêdo et al. 825; H–M: Facco et al. 494; N: Cavalcanti et al. CFCR 9682. Scale bar.A: 5 cm; B: 4 mm; C, G, N: 1 mm; D–F, L, M: 2 mm; K: 3 mm.

FIGURE 20. Geographical distribution of Cuphea auriflora, Cuphea inaequalifolia and Cuphea tenuissima.