Cuphea congesta Graham & Cavalcanti (1999a: 26)

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

7. Cuphea congesta Graham & Cavalcanti (1999a: 26) .

Type:— VENEZUELA. Bolívar: Parque Nacional Canaima [approx. 5.338, -62.038], 8 January 1973, Schwabe s.n. (holotype B [100248237] image!, isotype CEN [fragm.]!). Figs. 9A–F , 18 .

Subshrubs 37–150 cm tall; stems erect, indumentum strigose, one-armed trichomes, mixed with sparse glandular trichomes, ca. 0.5 mm long; internodes 0.5–2 cm long; brachyblasts absent. Leaves opposite, chartaceous to coriaceous, sessile to petiolate, petioles ca. 1 mm long, blades 15–35 × 2–10 mm, narrow-ovate, oblong to elliptic, apex acute, base subcordate to truncate, margin subrevolute, both surfaces glabrous to sparsely strigose, one-armed trichomes; brochidodromous, sometimes the secondary veins incospicuous. Racemes 6–15 cm long, frondose, simple to compound, elongated, indistinct; bracts 9–30 × 3–8 mm, subequal pairs, similar to leaves in shape and indumentum. Flowers alternate; pedicels 5–6 mm long; bracteoles ca. 1 mm long, broad-ovate; floral tubes 15–21 mm long; spur saccate, strongly deflexed; outer surface yellow-green, indumentum densely glandular, rarely erect eglandular trichomes <0.5 mm long present; inner surface villous behind the stamens, densely pilose around the ovary, pilose on the rest of the floral tube; petals 6, pale yellow, subequal, ca. 2.5–3 × 1 mm, narrow-obovate; stamens free in the upper third of the floral tube, five antesepalous exserted, four antepetalous subexserted; pistil ca. 16 mm long; ovary glabrous; style glabrous; ovules 3; nectary ca. 1 × 1.3 mm, deflexed. Seeds number unknown, 3–3.2 × 2.3–2.7 mm, narrow-elliptic to suborbicular, apex obtuse to slightly retuse, base obtuse, margin obtuse.

Phenology: —Collected with flowers in January, March, and July; fruits in January and July.

Distribution and habitat: — Venezuela, in Bolívar state ( Fig. 18 ); river beaches, in savannas; 390–430 m elev.

Conservation status: — Cuphea congesta was categorized as Data Deficient (DD), a classification influenced by the low number of specimens found, leaving it uncertain whether the species has a sampling deficit or if it is rare in the region.

Specimens examined: — VENEZUELA. Bolívar: Río Carrao , Alto Caroní, Guayana Venezolana, alrededores Salto Hacha, 06º15’00”N, 62º51’00”W, March 1954, Puig 2883 (US image!) ; región de Canaima, isla de la laguna del Río Carrao , frente del Salto Hacha y el hotel, 06º15’00”N, 62º47’00”W, 18 July 1972, Steyermark 106332 ( P!) ; Parque Nac. Canaima, 08 January 1973, Schwabe s.n. [58] ( B [100248238] image!); Canaima, 09 January 1973, López-Palacios 3062 ( P!) .

Cuphea congesta is identified by the long yellow-green floral tubes, 15–21 mm long, with saccate spur, the pale yellow petals, and large seeds ( Fig. 9F ), 3–3.2 mm long. It is endemic to Venezuela, occurring in the state of Bolívar within the Guiana Shield, with sparse records in the savannas of Canaima National Park and adjacent regions. Cuphea congesta is morphologically similar to the sympatric C. anisoclada . The smaller floral tubes ( Fig. 6C ), 10–13 mm long, with obtuse spur, and smaller seeds, 1.7–1.8 mm long, differentiate C. anisoclada from C. congesta .

Graham & Cavalcanti (1999a) classified C. congesta in C. sect. Melvilla because of the long, thick floral tubes. Within the section, it was placed in C. subsect. Pachycalyx Koehne (1877: 230) due to the low number of ovules, nonciliate sepals and the South American distribution ( Graham & Cavalcanti 1999a). On the other hand, it was observed that C. congesta has several synapomorphies of C. sect. Trispermum s.l., such as pollen grains with thickened exine between the pores ( Graham & Cavalcanti 1999a), 3 ovules, deflexed nectary, and obtuse margin seeds. According to Graham et al. (2006) and Barber et al. (2010), the large floral tubes that define C. sect. Melvilla appear to be convergences related to adaptation to large pollinators, such as birds and bees, which are attracted by the color of the floral tube and the nectar that accumulates in the spur. In this way, C. congesta was transferred to C. sect. Trispermum s.l. in this revision.

Figures

FIGURE 6. A–E. Cuphea anisoclada. A. Habit; B. Detail of a branch; C. Lateral view of floral tube; D. Pistil; E. Seed. F–K. Cuphea antisyphilitica. F. Habit; G. Flowering branch; H. Floral tube in lateral view, without petals; I. Floral tube in longitudinal-dorsal section, without petals; J. Pistil; K. Seed. A: Maguire 33644; B–E: Steyermark et al. 115626; F: Sevilha et al. 5684; G: Facco et al. 497; H–J: Facco et al. 490; K: Absy 187. Scale bar.A: 5 cm; C, H: 3 mm; D, I, J: 2 mm; E, K: 1 mm. Photo. F: Anderson Sevilha.

FIGURE 9. A–F. Cuphea congesta. A. Flowering branch; B. Detail of the leaves; C. Floral tube in lateral view, without petals; D. Floral tube in longitudinal-dorsal section, without petals; E. Pistil; F. Seed. G–M. Cuphea cunninghamiifolia. G. Flowering branch; H. Detail of contracted bracteose raceme; I. Flower in frontal view; J. Floral tube in lateral view, without the petals; K. Floral tube in longitudinaldorsal section, without the petals; L. Pistil; M. Seed.A: Puig 2883; B–E: Steyermark 106332; F: Lopez & Palacios 3062; H, L: Cavalcanti et al. 3621; J, K, M: Ribeiro & Diniz-Neres 569. Scale bar.A: 5 cm; B–E: 3 mm; F, M: 1 mm; H: 1 cm; J–L: 2 mm. Photos. G, I: Maurício Mercadante.

FIGURE 18. Geographical distribution of Cuphea anisoclada, Cuphea congesta, Cuphea gracilis and Cuphea rionegrensis.