Cuphea laricoides Koehne (1877: 292)

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

13. Cuphea laricoides Koehne (1877: 292) .

Lectotype (first step designated by Lourteig 1987: 43 , second step lectotypification here designated):— BRAZIL. Piauí: “ Habitat in provincia Piauhy ” [ Tranqueira ], March 1839, Gardner 2163 ( P [01901773] image!, isolectotypes F [2 sheets] image!, GH image!, K [2 sheets] image!, L image!, NY [2 sheets] image!, OXF image!, P [01901772; 01901774] image!, W [3 sheets] image!) . Figs. 12A–H , 21 .

Subshrubs 15–80 cm tall; stems usually decumbent forming clumps, rarely erect or prostrate, indumentum pubescent and strigose, eglandular trichomes <0.5 mm long, erect or with curved apices, and one-armed trichomes, sometimes sparse glandular trichomes present, often the indumentum is distributed in a longitudinal band along the stem; internodes 0.3–1.5 mm long; brachyblasts present. Leaves usually 3-verticillate, coriaceous, sessile, blades 2–8 × 0.8–1.5 mm, linear to narrow-ovate, apex acute, base truncate to obtuse, margin subrevolute to revolute, rarely plane, indumentum strigose on both surfaces; hyphodromous. Racemes 7–20 cm long, frondose, compound, elongated, indistinct; bracts 3–6 × 0.8–1.5 mm, subequal pairs, similar to leaves in shape and indumentum. Flowers alternate, rarely opposite; pedicels 2–3 mm long; bracteoles 1–1.5 mm long, ovate, oblong to suborbicular; floral tubes 6–8 mm long; spur obtuse to slightly saccate, deflexed; outer surface purple on dorsal region, green ventrally, indumentum pubescent, mixed with glandular trichomes, rarely just strigose; inner surface villous behind the stamens, dense-pilose on the rest of the floral tube, mainly on the veins in the lower third of the tube; petals 6, lilac to white, subequal, two dorsal 5.5–6 × 1.8–3 mm, narrow-obovate to obovate, four ventral 5.5–6.5 × 1.5–3 mm, narrow-obovate to obovate; stamens free in the upper third of the floral tube, five antesepalous exserted, four antepetalous subexserted; pistil 4.5–5.2 mm long; ovary glabrous, rarely pilose on the dorsal line; style pilose at base or glabrous; ovules 3(–4); nectary 0.6–0.7 × 0.5–1 mm, deflexed. Seeds 2–3, 1.8–2.3 × 1.8–2.3 mm, broad-obovate to suborbicular, apex slightly retuse to obtuse, base slightly acute, margin obtuse.

Phenology: —Collected with flowers and fruits all year round.

Distribution and habitat: — Brazil, in the states of Bahia, Ceará, Maranh ã o, and Piauí ( Fig. 21 ); sandstone outcrops, in transition vegetation between Caatinga-Cerrado; 150–630 m elev.

Conservation status: — Cuphea laricoides was categorized as Least Concern (LC) due to its wide geographic distribution, forming dense populations.

Representative specimens examined: —BRAZIL. Bahia: “Marais de Japira près Villa de Barra”, 1840, Blanchet 3079 (BR image!, F image!, K image!, NY image!, P image!, W image!); Gentio do Ouro, 20 km S de Xique-Xique, camino a Santo Inácio, 11º01’00”S, 42º43’00”W, 19 January 1997, Arbo et al. 7507 (CEN!, CEPEC!); Pil ã o Arcado, Barra do Lú, ca. 30 km Oeste de Pil ã o Arcado, 10º04’16”S, 42º50’09”W, 18 March 2006, Miranda et al. 950 (CEN!, HUEFS!). Ceará: Crateús, RPPN Serra das Almas, 26 February 2002, Araújo & Girão 1324 (EAC image!); Crateús, Serra das Almas, 20 March 2014, Teixeira 26 (EAC image!). Maranhão: Barreirinhas, 01 November 2004, Silva 4 (MG!); na estrada de piçarra entre S. Jo ã o dos Patos e Bar ã o de Grajaú, 02 May 1979, Fernandes et al. s.n. (EAC [6063] image!). Piauí: Altos, PI-221, Altos-Alto Longá, Km 5, 05º03’51”S, 42º25’32”W, 05 May 2018, Pereira-Silva et al. 17173 (CEN!); Caracol, Parque Nacional da Serra das Confusıes, entre o Portal do Parque e a descida da Serra das Confusıes, 09º13’18”S, 43º29’20”W, 20 February 2013, Martinelli et al. 18053 (RB!); Monsenhor Gil, BR-316, a 4 km ao sul de Monsenhor Gil, 05º36’10”S, 42º36’43”W, 04 May 2018, Pereira-Silva et al. 17164 (CEN!); Oeiras, April 1839, Gardner 2164 (F image!, GH image!, K image!, L image!, NY image!, P image!, W image!); Oeiras, 1877– 78, Jobert 1041 (P image!); Oeiras, estrada para Tanque do Piauí, 06º56’45”S, 42º04’34”W, 14 March 2005, Queiroz et al. 10184 (CEN!, HUEFS!); Oeiras, BR-230, Oeiras-Picos, morros de arenito na saída da cidade, 07º00’00”S, 42º06’51”W, 03 May 2018, Pereira-Silva et al. 17160 (CEN!); Oeiras, entroncamento da BR-230-Tanque do Piauí, ca. 4.5 km, 06°55’09”S, 42°04’57”W, 03 May 2018, Pereira-Silva et al. 17161 (CEN!); Pedro II, descida da Serra do Gritador, 04º19’39”S, 41º27’16”W, 06 May 2018, Pereira-Silva et al. 17186 (CEN!); Piracuruca, Parque Nacional das Sete Cidades, 04º06’11”S, 41º41’27”W, 06 May 2018, Pereira-Silva et al. 17180 (CEN!); Piripiri, BR-404, Piripiri-Pedro II, Km 14, 04º25’41”S, 41º43’02”W, 06 May 2018, Pereira-Silva et al. 17184 (CEN!).

Cuphea laricoides is characterized by its decumbent habit, often in clumps ( Fig. 12A ), the presence of brachyblasts on the branches ( Fig. 12B ), and linear to narrow-ovate, 3-verticillate, hyphodromous leaves, with a generally revolute margin. The color of the petals can vary from white to lilac within the same population ( Fig. 12C, D ). It occurs in northeastern Brazil on sandstone outcrops in the Caatinga-Cerrado transition, forming large populations in the state of Piauí, and sparse records in northern Maranh ã o (near Lençóis Maranhenses National Park), western Ceará, and northwestern Bahia.

Cuphea laricoides is morphologically similar to the linear-leaved species C. araguaiaensis , C. ericoides , and C. paralarix . Brachyblasts are absent in C. ericoides , and the leaf margin is plane. Cuphea araguaiaensis and C. paralarix have brachyblasts, however, C. paralarix is distinguished by its plane leaf margin and yellow flowers, and C. araguaiaensis by its erect habit and opposite leaves. Because of its close morphological similarity to the mentioned species, specimens of C. laricoides were included in phylogenetic analyses using AFLPs and ITS markers (Facco, unpublished data). The results revealed that C. laricoides is well defined, as well as the other related species.

Figures

FIGURE 12. A–H. Cuphea laricoides. A. Habit; B. Branch with brachyblasts; C–D. Branches with white (C) and lilac (D) flowers; E. Floral tube in lateral view, without petals; F. Floral tube in longitudinal-dorsal section, without petals; G. Pistil; H. Seed. I–N. Cuphea micrantha. I. Habit; J. Flower in lateral view and ruptured fruit with exposed placenta carrying a seed; K. Floral tube in lateral view, without petals; L. Floral tube in longitudinal-dorsal section, without petals; M. Pistil; N. Seed. A: Pereira-Silva et al. 17161; B, D, G, H: Pereira-Silva et al. 17160; C, E, F: Pereira-Silva et al. 17180; I: Pereira-Silva et al. 17081; K, M, N: Sevilha et al. 5872; L: Scariot et al. 386. Scale bar. E–G, L, M: 2 mm; H, N: 1 mm; K: 3 mm. Photo. J: Joel M.P. Cordeiro.

FIGURE 21. Geographical distribution of Cuphea bahiensis, Cuphea cunninghamiifolia, Cuphea laricoides and Cuphea praetermissa.