Molecular and morphological notes on Opuntia ser. Streptacanthae (Cactaceae) Author Martínez-González, César Ramiro 0000-0002-0256-0840 Posgrado en Biotecnología Agrícola, Instituto de Horticultura, Departamento de Fitotecnia, Universidad Autónoma Chapingo, Chapingo, México, 56230, Texcoco, Estado de México, México. & cesar. ramiro. mg @ gmail. com; https: // orcid. org / 0000 - 0002 - 0256 - 0840 cesar.ramiro.mg@gmail.com Author Gallegos-Vázquez, Clemente 0000-0003-2506-8274 Posgrado en Biotecnología Agrícola, Instituto de Horticultura, Departamento de Fitotecnia, Universidad Autónoma Chapingo, Chapingo, México, 56230, Texcoco, Estado de México, México. & cgallegosvazquez @ gmail. com; https: // orcid. org / 0000 - 0003 - 2506 - 8274 cgallegosvazquez@gmail.com Author Mascorro- Gallardo, José O. 0000-0001-9713-4758 Posgrado en Biotecnología Agrícola, Instituto de Horticultura, Departamento de Fitotecnia, Universidad Autónoma Chapingo, Chapingo, México, 56230, Texcoco, Estado de México, México. & jomg 1 @ yahoo. com. mx; https: // orcid. org / 0000 - 0001 - 9713 - 4758 jomg1@yahoo.com.mx Author Barrientos-Priego, Alejandro F. 0000-0001-6555-7633 Posgrado en Biotecnología Agrícola, Instituto de Horticultura, Departamento de Fitotecnia, Universidad Autónoma Chapingo, Chapingo, México, 56230, Texcoco, Estado de México, México. & abarrien @ gmail. com; https: // orcid. org / 0000 - 0001 - 6555 - 7633 abarrien@gmail.com text Phytotaxa 2022 2022-12-15 576 1 1 28 http://dx.doi.org/10.1094/PDIS-04-22-0755-PDN journal article 209394 10.11646/phytotaxa.576.1.1 87841c94-3925-497b-8801-549e93467c87 1179-3163 7440876 Opuntia hyptiacantha F.A.C. Weber (1898: 894) Neotype (designated by Scheinvar et al . 2010: 287 ): — MEXICO . San Luis Potosí , 13 Km northwest of San Luis Potosí, 01 May 1973 , Sánchez-Mejorada 1734 ( MEXU !). Description:— Plant 2.0– 2.5 m high tree ( Fig. 15A ). Defined trunk , 35 cm in diameter, slightly grayish scaly bark with light brown tones ( Fig. 15B ). Glabrous epidermis ( Fig. 18C ). Elliptical to oval cladodes , 32–40 cm long x 14–24 cm wide and 2–3 cm thick, green in color, covered with a light layer of wax ( Fig. 16A ). Areolas arranged in 12–13 series, 3.6 cm spacing between series, 3.4 cm spacing between elliptical areolas, 0.4 × 0.3 cm , short black trichomes, ( Fig. 16B ). Very small and scarce yellow glochids, arranged at the top of the areola. 0–9 white spines, yellowish apex, rigid, generally erect and diffuse, some of which are generally adpressed at the edge, unequal in length, 0.3–2.1 cm , the lower part of the cladode has no spines ( Fig. 16C ). Juvenile cladodes with prominent tubers, areolas with short brown to black trichomes, some reddish white bristle hairs, erect subulate green leaves, with reddish apex ( Fig. 15C ). Acute flower buds , reddish perianth segments with accumulated apex, elliptical pericarpel, slightly elevated tubers, areolas with short brown trichomes, brown glochids and areolas with brown bristles ( Fig. 16D and 16E ). Yellow flowers ( Fig. 16F ), 6.0–7.0 cm long, elliptical pericarp, ca. 3.4 × 2.3 cm , areolas arranged in 5–6 series, 0.66 cm spacing between them, with crass basal scale, outer segments of the perianth with obovate form, mucroned apex, smooth yellow edges, with medium greenish striation, reddish apex, oblanceolated inner segments, emarginated apex, yellow with reddish apical part, upper edges slightly dentate, stamens 1/3 of the length of the perianth, reddish and yellow filaments, yellow anthers, cuneiform style, ca. 1.9 cm long, light green, usually eight green papillary lobes of stigma, ca. 0.5 cm long, with medium white pink striation ( Fig. 17B ). Red elliptical fruits ( Fig. 17C ), 5.0– 6.5 cm long, sunken floral striated scar, large and circular to elliptical areolas, ( Fig. 17E ), arranged in 4–5 series, 1 cm spacing from each other and 0.7 cm between series, long black trichomes, some spines, short yellow glochids, juicy and sweet pink red funicles ( Fig. 17D ). Lenticular seed with irregular lateral aril, lateral trhead-micropilar region, micropilum and funiculus included ( Fig. 17F ). FIGURE 16. Opuntia hyptiacantha . A. Elliptical cladode. B. Elliptical areola, short black trichomes. C. Erect and diffuse white spines with yellowish apex. D. Acute flower buds, reddish segments of perianth with auminate apex. E. Flower button, side view, elliptical pericarpel. F. Flower in anthesis. FIGURE 17. Opuntia hyptiacantha . A. Lateral view of the flower. B. Longitudinal cut of the flower, reddish and yellow filaments, yellow anthers, green cuneiform style, eight green stigma lobes. C. Elliptical fruit. D. Longitudinal cut of the fruit, pink red funicles. E. Areola of fruit, circular with long trichomes, yellow glochids. F. Lenticular seed with irregular lateral aril. Micromorphology:— Thornswith lignified epidermal cells 98.35 ± 1.40 × 23.64 ± 1.10 μm in the distal part ( Fig. 18B ), 61.22 ± 1.30 × 12.04 ± 1.40 μm, continuous epidermal cells and rough texture, in the middle part ( Fig. 18A ). Glabrous epidermis, irregular epidermal cells ( Fig. 18C ) and paracytic stomas ( Fig. 18D ). Polyhedron-shaped pollen grain hexagonal, pantoaperturate ( Fig. 18E ), 111.16 ± 1.40 μm in diameter, 8432.28 μm ² in area, 10.10 ± 1.90 μm distance between each distal opening (pores), with a diameter of 22.50 ± 1.50 μm, 15–17 pores with walls of 1.85 ± 0.14 μm width and wart ( Fig. 18F ). FIGURE 18. Opuntia hyptiacantha . A. Epidermal cells of the middle part of the thorn, continuous cells without fissures between the cells and with rugose texture. B. Epidermal cells of the apical part of the thorn. C. Glabrous epidermis. D. Irregular epidermal cells, paracytic stoma. E. Polyhedron-shaped pollen grain hexagonal, pantoaperturate. F. Approach to a pore, warty walls. Vernacular names:— Nopal cascarón , tuna mansa, tuna corriente and Tuna chaveña (see e.g., Bravo-Hollis 1978 , Anderson 2001 , Scheinvar 2004 ). Phenology:— Opuntia hyptiacantha blooms from March–April, whereas fruiting time if June–July. Habitat and distribution:— Endemic to Mexico , it is known in the states of Aguascalientes , Ciudad de México , Guanajuato , Hidalgo , Jalisco , México , Oaxaca , Puebla , Querétaro , San Luis Potosí , Tlaxcala and Zacatecas (see e.g., Arias et al. 1997 , Guzmán et al . 2003 , Scheinvar 2004 , Scheinvar et al. 2010 , Arias et al. 2012 , Hernández et al. 2014 ) ( Fig. 2 ). It grows in xerophytic scrub ( Rzedowski 1978 ).