taxonID	type	description	language	source
A67831A0CC0A5090B27AF6936DD1B820.taxon	description	Figs 1, 2, 3, 4, 5, 6, 7, 8	en	Manley, Debra L., Lichter Marck, Isaac H., Peralta, Keily, Castro Castro, Arturo, Wogan, Kelsey A., Whiting, Carolyn V., Powell, A. Michael (2025): Ovicula biradiata, a new genus of Compositae from Big Bend National Park in Trans-Pecos Texas. PhytoKeys 252: 141-162, DOI: 10.3897/phytokeys.252.137624
A67831A0CC0A5090B27AF6936DD1B820.taxon	description	Description. Annuals, small, flowering plants usually 1 – 2 (– 3) cm tall, from less than 1 cm wide to 3 – 7 cm across, whole plants densely white-tomentose. Root single, thread-like, 0.5 – 1 mm wide at the plant base. Stems unbranched, erect or branches, if evident, lateral, prostrate, spreading 1 – 4 cm in one or more directions, internodes ca. 1 cm long. Leaves basal, mostly in tight clusters or at nodes on short stems, proximal leaves spreading, distal ascending, petioles 1 – 4 mm long, blades ovate, 4 – 7 × 2.5 – 5 mm, entire, planar, gently involute or nearly conduplicate. Heads heterogamous, borne singly, essentially sessile (peduncles to ca. 1 mm long), obscured by woolly leaves. Involucres 5 – 7 × 4 – 6 mm, broadly funnelform to campanulate or subglobose. Phyllaries in 3 series, ca. 1 – 2 in outer series, ca. 1 – 2 in second series, outer slightly spreading, those in outer 2 series 3 – 4 × 2 – 3 mm, ovate, inner series ca. 7, linear, ca. 2 mm wide, with scarious margins ca. 0.5 mm wide, densely white-tomentose. Receptacles ca. 1 mm across, slightly saucer-shaped to flat, sometimes with a very small conic enation from near centre, otherwise basically smooth or with faint floret scars, epaleate. Ray florets 2 (– 3) per head, 3 – 6 × 0.6 – 1 mm long, positioned on opposing sides, pistillate and fertile, strap-like; corolla tube 2 – 3 mm long, densely pilose distally, with wavy trichomes 0.3 – 1 mm long, laminae 3 – 6 × 0.6 – 1 mm, 3 - lobed, whitish, markedly 4 - nerved proximally, 6 - nerved distally, nerves maroon, proximal portion of the abaxial ray laminae densely covered with sessile or short stipitate glandular trichomes. Disc florets 10 – 12 per head, perfect and fertile; corolla pale yellow, ca. 2 – 3 mm long, tube 0.6 – 0.9 mm long, throat 1.6 – 1.8 mm long, lobes 5, 0.1 – 0.3 mm long, distalmost throat and lobes densely pilose with wavy trichomes 0.3 – 0.5 mm long; anthers yellow, distal anther appendage narrowly obovate to subsagittate; style tip appendage truncate, apex papillate. Cypselae of ray and disc florets similar, 1.5 – 2 mm long, obconic-obpyramidal, slightly compressed or obscurely 4 – 5 - angled (prismatic), ribs 4 – 5, densely pubescent with straight, ascending-appressed, silvery trichomes 0.5 – 0.9 mm long, minutely forked at tip, partially obscuring the bases of pappus scales. Pappus of ray and disc florets similar, scales 5, ca. 1 – 3 × 0.8 – 1 mm, ovate, hyaline, with an apical arista ca. 1 mm long; the scales spreading when dry (Figs 1 – 7). Chromosome number unknown. Similar to members of tribe Helenieae (sensu Baldwin et al. (2002)), especially Tetraneuris, with its annual habit, radiate heads, phyllaries in 3 series, convex, epaleate receptacles, ray florets pistillate and fertile, strap-like 3 - lobed ray floret laminae with prominent, coloured veins, cypselae obconical, faintly ribbed and pappus of hyaline aristate scales, disc florets perfect and fertile, corollas yellow, 5 - lobed; differs from other Helenieae genera by its smaller size, shorter stems, tightly clustered small leaves, greater tomentum density and smaller, sessile heads with only 2 (– 3) ray florets.	en	Manley, Debra L., Lichter Marck, Isaac H., Peralta, Keily, Castro Castro, Arturo, Wogan, Kelsey A., Whiting, Carolyn V., Powell, A. Michael (2025): Ovicula biradiata, a new genus of Compositae from Big Bend National Park in Trans-Pecos Texas. PhytoKeys 252: 141-162, DOI: 10.3897/phytokeys.252.137624
A67831A0CC0A5090B27AF6936DD1B820.taxon	etymology	Etymology. The generic name from Latin Ovis “ sheep ” and - cula (diminutive ending) references the dense woolly indumentum of this new plant. The name honours the desert bighorn sheep (Ovis canadensis nelsonii), an iconic, but threatened desert animal that is currently rebounding in this part of the Chihuahuan Desert, providing hope for other rare species like O. biradiata. The specific epithet biradiata references the typically two conspicuous ray florets, occasionally three per head, positioned on opposing margins of the capitulum (Figs 1, 4). A recommended common name for O. biradiata is “ woolly devil ”, in reference to the woolly indumentum, the proximity of populations to the locality known as Devil’s Den and the tendency for the ray florets to resemble horns.	en	Manley, Debra L., Lichter Marck, Isaac H., Peralta, Keily, Castro Castro, Arturo, Wogan, Kelsey A., Whiting, Carolyn V., Powell, A. Michael (2025): Ovicula biradiata, a new genus of Compositae from Big Bend National Park in Trans-Pecos Texas. PhytoKeys 252: 141-162, DOI: 10.3897/phytokeys.252.137624
A67831A0CC0A5090B27AF6936DD1B820.taxon	distribution	Distribution and phenology. Ovicula biradiata is known from limestone pediments of eastern Big Bend National Park where only three small populations have been found. Within these subpopulations, individual plants were abundant, but short-lived, indicating an ephemeral life history. The species was discovered on 2 March 2024 when plants were in full flower (Fig. 1). It is not presently known how early the plants may produce flowers, but, in the same general area, there are other species in several families that may bloom in early February or even earlier. By late May, after a period of warm and dry weather, the delicate annual plants had ceased vegetative growth and only desiccated inflorescences could be found (Fig. 4).	en	Manley, Debra L., Lichter Marck, Isaac H., Peralta, Keily, Castro Castro, Arturo, Wogan, Kelsey A., Whiting, Carolyn V., Powell, A. Michael (2025): Ovicula biradiata, a new genus of Compositae from Big Bend National Park in Trans-Pecos Texas. PhytoKeys 252: 141-162, DOI: 10.3897/phytokeys.252.137624
