Pinguicula filifolia subsp. alba Y.Domínguez, Panfet & V.Miranda, subsp. nov. (Fig. 1)

Differs from P. filifolia subsp. filifolia in the larger number and length of leaves and inflorescences; white flowers with oblongspathulate lobes; conical spur, angle between spur and corolla tube of 99°–110°, calyx lower-lip lobes connate (0.5–0.8 mm); capsule globose; seeds smaller with anticlinal exotesta walls thickened and almost flat.

Type: — CUBA. Pinar del Río: Mantua, Playa “La Cana”, Reserva Ecológica “Los Pretiles”, pinares sobre arenas blancas, 4 m. a.s.l., 22°26'21''N, 84°17'58''W, 4 January 2012, Y. Domínguez, C. Panfet & R. Novo 313 (holotype HAJB–PFC 87590!; isotypes HUMC 5321!, HFA!, JABU!).

Annual rosulate herb. Rhizome short, with numerous adventitious roots. Leaves 18–23(–30), 9.5–10.5 × 0.2–0.3 mm, linear-filiform, erect, green-yellowish, margin entire, plane, apex acute, circinate, base cuneate, adaxial surface moderately covered with stalked and sessile glands, abaxial surface glabrous. Plantlets leaves 4–8, 4–5.5 × 1.5 mm, flat to suberect, spathulate, base cuneate, apex rounded to obtuse, margin entire, planar. Inflorescence (3–)6–8(–13), erect, 15–18 cm tall, 1 mm in diameter, 1-flowered, sparsely covered with stalked and sessile glands. Flower (12.5–)13.5–15(–18) mm long (spur included). Calyx 2-lipped, sepals oblong, apex rounded, greenyellowish, sparsely covered with stalked glands; upper-lip sepals 3, each 1.5–2 × 1 mm, entirely divided; lower-lip sepals 2, each 1–1.5 × 0.5 mm, connate 0.5–0.8 mm from the base. Corolla subisolobate, lobes 3–4.3(–5) × (2.5–)3–3.7(–4) mm, white, oblong-spathulate, apex rounded to truncate; tube (3.5–)4–4.5(–5) × 1.8–2.5(–3.2) mm, cylindric, outside yellow with brown stripes, inside yellow, covered with long-stalked multicellular-headed hairs; spur 3.5–4(–4.5) × 3–3.5 mm, conic, apex rounded-truncate, yellow-brownish, forming an angle of 99°–106°(– 110°) with the tube. Capsule 1.7–2 × 1.7–2 mm, globose, ± half covered by the persistent calyx. Seeds (339–)379– 450(–509) µm × (117–)169–190(–229) µm, elliptic-oblong, dark brown; exotesta cells ± rectangular-polygonal, arranged in longitudinal-spiral rows, anticlinal walls thickened, not pronounced; micropylar appendage (30–)37– 47(–56) µm (Fig. 2A–B).

Etymology: —The subspecific epithet refers to the invariable white color of the corolla.

Distribution and habitat: —Endemic to western Cuba (Fig. 3). It occurs in quartz sand planes (savannas) and open areas of Pinus forests at 0–10 m a.s.l., in the Ecological Reserve “Los Pretiles”, province Pinar del Río.

Conservation status:— The subspecies is proposed as Critically Endangered (CR) according to IUCN (2013) criteria B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv) due to its restricted geographic and spatial distribution within the area of occupancy (~ 10 km 2).

Other specimens examined (paratypes):— CUBA. Pinar del Río: Guane, Dimas, Playa La Cana cerca de Camarones, arenas blancas con pinos, September 1975, A. Areces et al. (HAC–PFC 40254!) ; Mantua, Dimas, Playa La Cana cerca de Camarones, arena blanca con Pinus, October 1975, A. Areces et al. (HAJB–PFC 28567!) ; Mantua, Playa la Cana SO de Dimas sobre arena blanca, 12 July 1978, J. Bisse et al. (HAJB–PFC 38731!) ; Mantua, Playa La Cana, al oeste del Arroyo Camarones arena silícea, veg. Pinar, 1–2 m., 5 December 1979, J.Bisse et al. (HAJB–PFC 41285!) ; Mantua, Playa La Cana, al este del Arroyo Camarones, arena silícea, pinar, 1–2 m., 5 December 1979, J. Bisse et al. (HAJB–PFC 41355!) ; Mantua, Playa La Cana, parte occidental del Pinar, 2 m., 29 March 1982, J. Bisse et al. (HAJB–PFC 46602!) ; Mantua, Isla de “Los Pretiles”, Reserva Ecológica “Los Pretiles”, Pinares sobre arenas blancas, 5 m. a.s.l., 22°25'40''N, 84°18'32''W, 4 January 2012, Y. Domínguez et al. 313 (HAJB–PFC 87592!, HFA!, HUMC 5322!) .