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 streptacantha Lemaire (1839: 62) Neotype (designated by Scheinvar et al . 2010: 283 ): — MEXICO . Hidalgo , Zempoala , east of Téllez basis of El Cerrito , 23 March 1973 , Scheinvar & Ahuatzin 2024 ( MEXU !). FIGURE 8. Opuntia lasiacantha . A. Obovate cladode. B. Elliptical areola, short black trichomes. C. Erect and diffuse yellowish white spines. D. Acute flower buds, red segments of perianth with acuminate apex. E. Flower button, side view, slightly cylindrical pericarpel. F. Flower in anthesis. = Opuntia streptacantha subsp. aguirriana Scheinvar & Rodríguez (2003: 304) . FIGURE 9. Opuntia lasiacantha . A. Side view of flower. B. Longitudinal cut of the flower, white filaments, and white-yellowish anthers, white with pink slightly cylindrical style, eleven green lobes of stigma. C. Elliptical fruit. D. Longitudinal cut of the fruit, orange red funicles. E. Circular areola of the fruit with short trichomes, yellow glochids. F. Kidney shaped seed with irregular lateral aril. FIGURE 10. Opuntia lasiacantha . 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, pantoaperturate. F. Approach to a pore, warty walls. Description:— Plant 2.0–3.0 m high tree ( Fig. 11A ). Defined trunk of 60 cm in diameter, grayish scaly bark with black shades ( Fig. 11B ). Glabrous epidermis ( Fig. 14C ). Oval cladodes, 32–40 cm long × 23–35 cm wide and 2–3 cm thick, green in color, covered with a very light layer of wax ( Fig. 12A ). Areolas arranged in 10–11 series, 3 cm spacing between series, 2.1 cm spaing between elliptical areolas of 0.4 × 0.3 cm , short black trichomes ( Fig. 12B ). Very small and scarce yellow gloquids , arranged at the top of the areola. 0–8 white spines with gray and black tones, flexible, acicular, some slightly twisted, adpressed and diffuse, very few erect, unequal of 0.2–2.2 cm long, yellowish apex, in the lower part of the cladode some areolas do not have spines ( Fig. 12C ). Juvenile cladodes with prominent tubers, areolas with short brown to black trichomes, some white bristel hairs with reddish tones, subulate, erect, green leaves, with uncinate slightly reddish apex, white spines with reddish apex ( Fig. 11C ). Acute flower buds , green perianth segments with reddish acuminate apex, elliptic pericarpel, slightly raised tubers, areolas with short black trichomes, brown glochids and brown bristle areolas ( Fig. 12D and 12E ). Yellow flowers ( Fig. 12F ), 5.5–6.1 cm long, elliptical pericarp, ca. 3.2 × 2.0 cm, areolas arranged in 4–5 series, 0.62 cm spacing between them, outer segments of perianth with spatulate shape, rounded apex, smooth yellow edges, with medium greenish striation, reddish apex, oblanceolated inner segments, emarginated apex, yellow, smooth upper edges, stamens 1/3 of the length of the perianth, yellow filaments, yellow anthers, white, cuneiform style, ca. 2.3 cm long, usually nine green papillary lobes of stigma, ca. 0.4 cm long, with medium white striation ( Fig. 13B ). Red elliptical to obovate fruits ( Fig. 13C ), 4–6 cm long, slightly sunken striated floral scar, circular to elliptical large areolas ( Fig. 13E ), arranged in 6–7 series, 1.1 cm spacing from each other and 1 cm between series, long black trichomes, some spines, yellow glochids, red juicy and sweet funicles ( Fig. 13D ). Discoid seed with irregular lateral aril, lateral thread-micropillar region, microphile and funiculus included ( Fig. 13F ). FIGURE 11. Opuntia streptacantha . A. 2.70 m high tree. B. Defined trunk, grayish scaly bark with black shades. C. Juvenile cladode with prominent tubers. FIGURE 12. Opuntia streptacantha . A. Oval cladode. B. Elliptical areola, short black trichomes. C. Adpressed and diffuse white spines with gray and black tones. D. Acute floral buttons, green segments of perianth with reddish acuminate apex. E. Flower button, side view, elliptical pericarpel. F. Flower in anthesis. Micromorphology:— Thornswith lignified epidermal cells 13.38 ± 1.90 × 3.59 ± 1.3 μm in the distal part ( Fig. 14B ), 114.01 ± 1.10 × 12.79 ± 1.20 μm, non-continuous epidermal cells with fissures between cells and smooth texture, in the middle part ( Fig. 14A ). Glabrous epidermis, irregular epidermal cells ( Fig. 14C ) and cyclocytic stomas ( Fig. 14D ). Polyhedron-shaped pollen grain, pantoaperturate ( Fig. 14E ), 114.64 ± 1.90 μm in diameter, 9219.1 μm ² in area, 13.89 ± 2.10 μm distance between each distal opening (pores), with a diameter of 21.49 ± 1.50 μm, 22–24 pores with walls of 2.43 ± 0.04 μm width and wart ( Fig. 14F ). FIGURE 13. Opuntia streptacantha . A. Lateral view of the flower. B. Longitudinal cut of the flower, yellow filaments and yellow anthers, white cuneiform style, nine green stigma. C. Obovate fruit. D. Longitudinal cut of the fruit, red funicles. E. Areola of fruit, circular with long trichomes, brown glochids. F. Discoid seed with irregular lateral aril. FIGURE 14. Opuntia streptacantha . A. Epidermal cells of the middle part of the thorn, with fissures between the cells and smooth texture. B. Epidermal cells of the apical part of the thorn. C. Glabrous epidermis. D. Irregular epidermal cells, cyclocytic stoma. E. Polyhedronshaped pollen grain, pantoaperturate. F. Approach to a pore, warty walls. Vernacular names:— Nopal cardón, Tuna cardona and Nopal hartón (see e.g., Bravo-Hollis 1978 , Scheinvar 2004 ). Phenology:— Opuntia streptacantha blooms from March–April, whereas fruiting time if June–July. Habitat and distribution:— Endemic to Mexico , it is known in the states of Aguascalientes , Chihuahua , Ciudad de México , Coahuila , Durango , Guanajuato , Hidalgo , Jalisco , México , Michoacán , Nuevo León , Oaxaca , Puebla , Querétaro , San Luis Potosí , Tlaxcala , Veracruz 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 and tropical deciduous forest ( Rzedowski 1978 ).