Chichimecactus corregidorae (S.Arias & E.Sánchez) Bárcenas, H.M.Hern., & P.Hern.-Led

Bárcenas, Rolando T., Hernández, Héctor M., Hernández-Ledesma, Patricia & Gómez, Luis Manuel Montoya, 2021, Chichimecactus (Cactoideae, Cactaceae), a new genus based on molecular characterisation of highly endangered Strombocactus species, Phytotaxa 512 (3), pp. 147-158 : 155-156

Chichimecactus corregidorae (S.Arias & E.Sánchez) Bárcenas, H.M.Hern., & P.Hern.-Led . comb. nov.

≡ Strombocactus corregidorae S.Arias & E.Sánchez (2010: 620) .

TYPE:— MEXICO. Querétaro: municipio de Cadereyta de Montes. Presa derivadora del sistema de conducción de agua Acueducto II , Comisión Estatal de Agua (CEA Querétaro), elevation 1500 m, 20°46’N, 99°30’W, 07 May 2008, Sánchez 338 (holotype MEXU !, isotypes IEB!, QMEX !).

Description: —Plants tubinate to globose-depressed when young, globose to cylindrical at adult stage. Stems to 18(– 21) cm high and 10(–13) cm in diameter, usually not ramified, greyish-green or glaucous, glabrous; roots thin, fibrous, superficial; tubercles rhomboid, strongly keeled, coriaceous; spines 3–5 per areole, 1.8–3.5 cm, differentiated into two short, straight and flexible in the adaxial region of the areole, and up to three abaxial, longer, thicker, curved and rigid, terete, subulate, grey when young, turning greyish-black with age, persistent, but absent in the lower portions of the stem. Flowers infundibuliform; ca. 2.5 cm long at anthesis in dry specimens, pericarpel green in the basal region, red at the distal region, with scales only at the apex; receptacular tube naked, the internal segments white to light yellow, lanceolate to spatulate, the external segments mostly reddish with yellow margins, triangular-obovate to narrowly oblanceolate; filaments numerous, greenish-white; pistil ca. 13 mm, exserted, yellow; stigma with ca. (9–)10(–12) lobes, yellow, the lobes ca. 3 mm. Fruits 9–11 mm, naked, ellipsoid, greenish-yellow when mature, laterally dehiscent. Seeds 0.4–0.5 mm, without strophiole, the testa finely rugose, with flat periclinal cell-walls.

Additional specimens examined: — MEXICO. Querétaro: municipio de Cadereyta de Montes. Presa derivadora del sistema de conducción de agua Acueducto II , Comisión Estatal de Agua (CEA Querétaro), E de Piñones, elevation 1,500 m, 20°46’N, 99°30’O. Same location, Bárcenas 1996 ( QMEX) ; ibidem, Sánchez 339 ( MEXU) ; ibidem, Sánchez 340 ( MEXU) ; ibidem, Zamudio 14107 ( IEB) .