Cypella aurinegra Deble & A.González, 2015

Deble, Leonardo Paz, Alves, Fabiano Da Silva, González, Andrés & Deble, Anabela Silveira De Oliveira, 2015, Three new species of Cypella (Iridaceae) from South America, and taxonomic delimitation of C. suffusa Ravenna, Phytotaxa 236 (2), pp. 101-120 : 102-105

Cypella aurinegra Deble & A.González , sp. nov. ( Figs. 1 , 2 , 5A–C )

Cypella aurinegra is closely related to C. fucata and C. luteogibbosa ; however, it can be distinguished from both species by its yellow flowers, with dark-purple stains in the blade, outer tepals narrowly oblong, stamens with filaments narrower and fused only in the base, divergent style branches, and seeds with smooth epidermis.

Type:— URUGUAY. Cerro Largo: Cañada Yerba Sola, “ 11 km al norte de Puntas del Parao”, 32° 37’ 36” S and 54° 22’ 51” W, 7 April 2014, A. González 2250 (holotype MVFA!).

Plant up to 8–22 cm high above the soil, underground stems up to 6 cm long. Bulb nearly globose, 8–17 × 7–15 mm, prolonged in a collar up to 4 cm; cataphylls light-brown, broadly ovate, apex acuminate. Leaves at anthesis absent or up to 2, blades narrowly linear 7–15 × 0.05–0.2 cm. Cauline leaf linear-ensiform, 4.5–6.5 × 0.1–0.2 cm, base sheathing the stem. Flowering stems 6–15 cm long, geniculate, furcate in distal third. Spathes 1–3 per branch, 2.4–2.8 × 0.2–0.3 cm, herbaceous, pallid-green, bivalved, one-flowered, shortly pedunculate, peduncles 1.2–1.8 cm long; outer valve 1.2–1.5 cm long, the inner 2.3–2.7 cm long, both with membranous edges covered with sparse parallel dark brown longitudinal glandular strips; pedicel filiform, 2–2.5 cm long. Flowers yellow, dark-purplish stained, and 28–36 mm diameter; central concavity 12–16 mm diameter, and 4–6 mm depth. Tepals whorls sharply dissimilar: outer tepals oblong, 20–22 mm long, concave at the base for 8–9 mm, slightly patent distally; blades yellow, darker-purple stained in two lateral bands at the base, 12–14 × 7–7.5 mm, slightly patent with margin undulated and facing upward, apices truncate or rounded, apiculate; claws broadly cuneate, 7–8 mm long, 1.5–1.9 mm wide at the base, and 6.5–7.8 mm wide at the apex, dull-yellow, translucent, not stained. Inner tepals geniculate-recurved, 6–7 mm long, the proximal half patent, slightly inclined, then curved upward, the distal one-third incurved and strongly reclined; blades 5.5–6 mm wide, yellow or sulfur-yellow, with a golden-yellow central depression densely clothed by glandular trichomes, surrounded by a lateral high part, yellow with dark-purple stains; claws cuneate, 5–5.5 mm long, 1.1–1.4 mm wide at the base, and 3.2–3.7 mm wide at the apex, dull yellow, translucent, with reddish-brown parallel stripes. Filaments filiform 2–2.5 mm long, porrect, dull-yellow, translucent, base dilated, without stains, attached for 0.3–0.4 mm; anthers oblong 4–4.4 mm × 1.4–1.7 mm; connective yellow, 1.1–1.4 mm, locules darker, pollen grey or ochraceous. Ovary pallid-green, 3.5–4.5 mm × 1.8–2.2 mm. Style 5.4–6 mm long. Style arms channeled, porrect, 3.5–4 mm long, crests at the apex 3, translucent and yellowish, adaxial crests lanceolate, 2.4–2.9 mm long, abaxial crest deltate, 0.8–1.1 mm long, at apex bifid. Capsule obovate, 9–10 mm × 5.5–6 mm, with glandular spots and stripes. Seeds oblong to obconical, 2–2.5 mm long, angulate, light brown, epidermis smooth, with ribs and folds.

Phenology:—Specimens with flowers and capsules can be found from January to April. The flowers bloom in the morning and wither midday. In cloudy days the flowers remain opened up to middle afternoon.

Etymology:–From the Latin “ aureus” that means gold-yellow and “ nigra” meaning black or dark, and referring the yellow flowers, with dark-purple stains at the base of the blades of outer tepals.

Additional specimen examined (paratypes):— BRAZIL. Rio Grande do Sul: Dom Pedrito, “cultivated from seeds of Deble 15105 ” 30 January 2015, L. P. Deble 15106 (SI!). URUGUAY. Cerro Largo: Arbolito, “Sources of Taquari river, on wet grasslands” 22 April 2014, L. P. Deble & A. S. de Oliveira-Deble 15105 (MVFA! SI!).

Distribution and habitat:— Cypella aurinegra occurs in the sources of Taquari River, Southern Cerro Largo Department, in Eastern Uruguay. Individuals grow at altitudes between 150–190 m, in wet grasslands close to the sources, in moist and usually deep soil above sandstone of the “Tres Islas” geological formation, Lower Permian (see Ferrando & Andreis 1990, Ferrando & Montaña 1987), where this species is probably endemic. Specimens occur in sympatry with C. fucata , but no intermediate forms were observed.

Conservation status:— Cypella aurinegra occurs in an extent of occurrence smaller than 10 km 2, the individuals known belong to a single population. Furthermore this population is composed by few individuals, which occur in high specialized habitat. According to the IUCN Red List assessment protocol ( IUCN 2013), the species can be assigned to Critically Endangered (CR, B1a, b(iii) + B2a, b(iii)) category.

Taxonomic relationships:— Cypella aurinegra belongs to sect. Cypella (sensu Ravenna 1981a, 1981b, 2003, 2009). By its lower habit, smaller flowers and features of floral organs is closely related with Cypella fucata Ravenna (1981b: 18) , C. luteogibbosa Deble in Deble et al. (2012c: 60), and C. osteniana Beauverd (1923: 165) . It can be distinguished from these species by its flowers yellow with dark-purple stains, outer tepals narrowed, smaller inner tepals, shorter adaxial crests of style branches, slender filaments, and seeds with smooth epidermis.

Note:—Seeds were cultivated in Brazil by the first author. The seeds were pre-cooled at 4–8ºC during 48 hours, then sown directly into a pot with organic substrate in May. They germinated after 10 days and the plants bloomed in January, after only 10 months.

Figures

FIGURE 1. Cypella aurinegra. A. Habit. B. Flower and spathe, lateral view. C. Flower, upper view. D. Flowers, tepals removed. E. Inner tepal. F. Capsule. G. Seed. H. Spathe with immature capsule. I. Crests of the style branches. J. Cauline leaf. K. Stamen (A–K from L.P. Deble et al. 15105).

FIGURE 2. Geographic distribution of Cypella aurinegra.

FIGURE 5. Cypella aurinegra. A. flower, upper view. B. flower, lateral view. C. Detail of stamens and style. Cypella gutatta. D. Flower, upper view. E. Flower, lateral view. F. Detail of stamens and style (A–B from L.P. Deble et al. 15105; C from González 2250; D from L.P. Deble et al. 14990; E–F from L.P. Deble et al. 14991).