Taxonomic update of the flax family in Mexico Author González-Velasco, Juan 0000-0001-8743-3906 Departamento de Botánica, Colegio de Postgraduados. km 36.5 carretera México-Texcoco, Montecillo, 56230 Texcoco, Mexico, Mexico. & gonzalez. juan @ colpos. mx; https: // orcid. org / 0000 - 0001 - 8743 - 3906 gonzalez.juan@colpos.mx Author Burgos-Hernández, Mireya 0000-0003-3036-297X Departamento de Botánica, Colegio de Postgraduados. km 36.5 carretera México-Texcoco, Montecillo, 56230 Texcoco, Mexico, Mexico. & burgos. mireya @ colpos. mx; https: // orcid. org / 0000 - 0003 - 3036 - 297 X burgos.mireya@colpos.mx Author Galván-Escobedo, Iris G. 0000-0003-4250-4971 Departamento de Botánica, Colegio de Postgraduados. km 36.5 carretera México-Texcoco, Montecillo, 56230 Texcoco, Mexico, Mexico. & igalvan @ colpos. mx; https: // orcid. org / 0000 - 0003 - 4250 - 4971 igalvan@colpos.mx Author Castillo-Campos, Gonzalo 0000-0002-3059-8109 Red de Biodiversidad y Sistemática. Instituto de Ecología A. C. Carretera antigua a Coatepec km. 351, El Haya, 91073, Xalapa, Veracruz, Mexico. & gonzalo. castillo @ inecol. mx; https: // orcid. org / 0000 - 0002 - 3059 - 8109 gonzalo.castillo@inecol.mx text Phytotaxa 2022 2022-06-08 549 2 141 184 journal article 67684 10.11646/phytotaxa.549.2.3 62e44cf6-6f9d-4658-a89b-a0ddf687b5b9 1179-3163 6622753 Linum neomexicanum Greene (1881: 183) . ( Fig. 7d ). Type :— UNITED STATES OF AMERICA . New Mexico : Pinos Altos Mountains , Greene s.n. ( holotype ND!, isotypes GH!, KANU, MO!) . Cathartolinum neomexicanum Small (1907l: 73) . Description: — Herbs , annual, 15–60 cm in height, glabrous, sometimes glaucous, root thin; stems erect, ascending, branching from the base, glabrous. Leaves entire, basal opposite, distal alternate, elliptical-oblanceolate, 8.0–15.0 × 1.0–1.8(–2.5) mm, sessile, apex subacute to acuminate, 1-nerved, rough, glabrous, stipular glands absent. Inflorescence a cymose panicle, thin, pedicels almost parallel to the stem, 1.0–4.0(–7.5) mm long; bracts 1.5–4.8 mm long, margin entire, apex acute, stipular glands absent; sepals persistent, linear-lanceolate to lanceolate, 2.3–4.1(–5.0) × 1.1–1.5 mm , margin glandular-dentate, apex acute to acuminate; 1-nerved, nervation evident; glabrous, stipular glands absent; petals yellow, oblanceolate, 4.0–7.0 mm long, glabrous; stamens 3.0–5.0 mm long; anthers 0.8–1.3(–1.5) mm long, orange; staminodia absent; styles free, 1.5–3.0 mm long; stigmata capitate, yellow. Fruit triangular-ovoid to widely ovoid, yellow with purple hues in the upper part, 1.7–2.6(3.5) × (1.9–) 2.7–3.5 mm , glabrous, pericarp thick, apex apiculate, dehiscent into 10 segments, false septa partially developed, septa with ciliate margins; seeds elliptical-ovate, pale reddish-brown, 2.0–2.5 × 1.1–1.3 mm . Distribution: — United States of America ; in Mexico , in Baja California , Chihuahua , and Sonora ( Fig. 5b ). Habitat and ecology: —Cypress-juniper forest, oak-pine forests, pine forests. Elevation 1700–2900 m . Phaeozem, Lithosol, Luvisol, Planosol, Regosol, and Vertisol soil types . Phenology: —Flowering and fruiting in March–November. Note: —It is easily distinguished by its thin inflorescence and pedicels parallel to the stem. Within its distribution range, it is the only species with yellow flowers and free styles. However, when reviewing herbarium specimens, several L. pringlei specimens with white flowers were misidentified as L. neomexicanum . Conservation status: —According to the IUCN Red List Categories and Criteria (2019), L. neomexicanum is Endangered (B2abc(iii)), as it has an AOO of 20 km 2 and ≤ 5 localities are known in the country. However, considering its EOO ( 159,584.708 km 2 ) and its distribution in the United States of America it probably can be considered as LC. Specimens examined: — MEXICO . Baja California : Sierra San Pedro Mártir , 2475 m , 31°02’00”N , 115°27’00”W , 21 July 1970 , R. Moran 17895 ( ENCB !) ; Sierra San Pedro Mártir , 2000 m , 31°04’00”N , 115°33’00”W , 15August 1967 , R. Moran & R.F. Thorne 14121 ( ENCB !) . Chihuahua : Guachochi , Rejogochi cerro oeste de Valle , 10/September/2002 , F. Wyndham 20 (CIIDIR!, MEXU !) ; Sierra Madre , 29 September 1887 , C.G. Pringle 1201 ( MEXU !) . Sonora : Agua Prieta , Arroyo Cajón del Diablo , 1772 m , 31°17’19”N , 108°47’49”W , 29 September 2009 , T.R. Van Devender et al. 1693 ( MEXU !) .