Cuphea pulchra Moricand (1847: 168)

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

18. Cuphea pulchra Moricand (1847: 168) .

Lectotype (designated by Graham 1990: 27):— BRAZIL, Bahia, “ Serra Jacobina [approx. -11.189, -40.500]”, 1836, Blanchet 2603 ( G [00227320] image!, isolectotypes BM image!, BR, F image!, G [00227321] image!, K [2 sheets]!, NY image!, OXF image!, P [2 sheets] image!, W [3 sheets] image!). Figs. 14H–N , 15A–G , 24 .

Cuphea coccinea Martius ex Koehne (1882: 405), nom. nud., pro syn.

Subshrubs to shrubs 40–200 cm tall; stems erect, indumentum pubescent, eglandular trichomes short, <0.5 mm long, erect or with curved apices, mixed with glandular trichomes ca. 0.5 mm long, sometimes one-armed appressed trichomes present or glandular trichomes absent; internodes 0.5–4 cm long; brachyblasts absent. Leaves opposite, chartaceous to coriaceous, sessile, rare petiole ca. 1 mm long, blades 10–55 × 7–21 mm, ovate to ovate-oblong, rarely elliptic or orbicular, apex acute, rarely obtuse or cuspidate, base subcordate to cordate, rarely obtuse, margin subrevolute to revolute, indumentum strigose on both surfaces, with one-armed trichomes, indumentum pubescent concentrated on the veins, sometimes glandular trichomes present; brochidodromous. Racemes 5–20 cm long, bracteose to frondosebracteose, simple to compound, usually contracted at apex of branches; bracts 2–30 × 1.2–15 mm, subequal pairs, ovate to oblong-ovate, similar to leaves in indumentum. Flowers alternate; pedicels 3–8 mm long; bracteoles 0.4–1.2 mm long, broad-ovate, rarely suborbicular; floral tubes (15–) 17–24 mm long; spur obtuse, saccate to galeate, deflexed; outer surface red-orange, apex yellow-green, indumentum pubescent, mixed with glandular trichomes; inner surface villous behind the stamens, dense-pilose around the ovary; petals 0 or 6, red-orange, subequal, two dorsal 3.5–4.2 x 3–4 mm, broad-obovate, four ventral 3–4.8 × 2.2–3 mm, broad-obovate to broad-elliptic; stamens free in the upper third of the floral tube, five antesepalous exserted, four antepetalous subexserted; pistil 16–23 mm long; ovary sparsely pilose to glabrous; style pilose; ovules 3–8; nectary 1.5 × 1.7–2 mm, deflexed. Seeds 3–4, 2.1–3 × 2–2.9 mm, obovate to suborbicular, apex truncate to slightly retuse, base acute to obtuse, margin obtuse.

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

Distribution and habitat: — Brazil, in the states of Bahia, Minas Gerais, Pernambuco, and Sergipe ( Fig. 24 ); cerrado sensu stricto, “campos rupestres”, rocky riverbanks, openings in hillside forests, gallery forest edges, and open “caatinga”; 200–1600 m elev.

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

Cuphea pulchra is easily recognized by the generally shrubby habit ( Fig. 14H ), up to 2 m tall, and the multiflorous racemes contracted at the apex of the branches ( Figs. 14J , 15B ), with long, red-orange floral tubes, (15–) 17–24 mm long. Individuals are typically apetalous. However, populations with six orange-red petals ( Fig. 15C ) were discovered in the state of Bahia, Brazil, and described as C. pulchra var. corollata ( Cavalcanti & Graham 2005) . Cuphea pulchra is recorded expressively in Bahia, forming dense populations in the Chapada Diamantina region, and with less frequency in the other states where it occurs.

Cuphea pulchra was classified in C. sect. Melvilla subsect. Pachycalyx by the long and robust floral tubes, a distinctive characteristic of the section, and by the low number of ovules, non-ciliate sepals, and South American distribution ( Koehne 1877 , 1903). Morphological and palynological studies by Graham (1990) and Graham & Cavalcanti (1999a) suggested that C. pulchra was closely related to C. sect. Trispermum by possessing several significant characters from this section. In the molecular phylogenetic analyses by Graham et al. (2006) and Barber et al. (2010), C. pulchra var. pulchra appeared in the “ Trispermum clade”.

Graham et al. (2006) commented that the large, colorful floral tubes found in the paraphyletic C. sect. Melvilla are convergent, certainly related to selection for large bees and bird pollination. According to photographic records ( Holderbaum 2013, Pongiluppi 2017), populations of C. pulchra in Chapada Diamantina, Bahia, are visited by hummingbirds.

Key to the varieties of Cuphea pulchra

1. Petals absent ................................................................................................................................................... C. pulchra var. pulchra

- Petals 6, red-orange ...................................................................................................................................... C. pulchra var. corollata

Figures

FIGURE 14. A–G. Cuphea praetermissa. A. Habit; B. Detail of 3-verticillate leaves; C. Abaxial surface of the leaf, margin strongly revolute to the midvein; D. Floral tube in lateral view, without petals; E. Floral tube in longitudinal-dorsal section, without petals; F. Pistil; G. Seed. H–N. Cuphea pulchra var. pulchra. H. Habit; I. Detail of a branch; J. Contracted raceme at the apex of the branch; K. Floral tube in lateral view; L. Floral tube in longitudinal-dorsal section; M. Pistil; N. Seed.A–D, G: Pastore et al. 2455; E: Bringel-Jr. & Moreira 709; F: Pastore et al. 2439; H–J, L–N: Facco et al. 487; K: Miranda & Conceição 682. Scale bar. A: 5 cm; B: 5 mm; C: 0.5 mm; D–F, N: 2 mm; G: 1 mm; K: 3 mm; L–M: 6 mm.

FIGURE 15. A–G. Cuphea pulchra var. corollata. A. Detail of a branch; B. Contracted raceme at the apex of the branch; C. Flower in frontal view; D. Floral tube in lateral view, without the petals; E. Floral tube in longitudinal-dorsal section, without the petals; F. Pistil; G. Seed. H–M. Cuphea rionegrensis. H. Branches with flowers; I. Detail of an immature fruit; J. Floral tube in lateral view, without petals; K. Floral tube in longitudinal-dorsal section, without petals; L. Pistil; M. Seed. A–G: Facco et al. 488; H, J–L: Poole 1790; I: Kubitzki et al. 126; M: Maia et al. 256. Scale bar. D–F: 6 mm; G, J–L: 2 mm; H: 5 cm; M: 1 mm.

FIGURE 24. Geographical distribution of Cuphea pulchra var. pulchra and Cuphea pulchra var. corollata.