Linum pringlei S.Watson (1888: 269)

González-Velasco, Juan, Burgos-Hernández, Mireya, Galván-Escobedo, Iris G. & Castillo-Campos, Gonzalo, 2022, Taxonomic update of the flax family in Mexico, Phytotaxa 549 (2), pp. 141-184 : 165

Linum pringlei S.Watson (1888: 269) . ( Fig. 9b ).

Type:— MEXICO. Chihuahua: shaded slopes, Sierra Madre, Pringle 1200 (holotype US!, isotypes GH!, MSC, NY!) .

Cathartolinum pringlei Small (1907c: 74) .

Description:— Herbs, perennial, 23–68 cm in height, glabrous, root thin; stems erect, branched from near the base, rigid ascending branches, extended, glabrous. Leaves, basal entire, opposite; distal discretely dentate, alternate; lanceolate or oblanceolate, 8.0.0–19 × 0.7–3.5 mm, sessile, apex acute or rounded, 2-nerved, membranous, glabrous, stipular glands absent. Inflorescence a cymose panicle, pedicels 3.0–14.0 mm long; bracts 1.7–3.4 mm long, margin sparsely dentate, apex acute, stipular glands absent; sepals persistent, ovate to lanceolate, 3.0–4.5 × 0.8–2.1 mm, margin entire or sparsely dentate above the mid portion to glandular-dentate, apex acute to acuminate, 1-nerved, glabrous, stipular glands absent; petals white to pinkish, oblanceolate, 5.0 – 8.0 mm long, glabrous; stamens 2.0–3.0 mm long; anthers 0.6–0.8 mm long, light yellow; staminodia present; styles free, 1.1–2.0 mm long; stigmata capitate, white. Fruit ovoidpyriform, yellow with purple hues in the upper part, 2.3–2.7 × 2.3–2.8 mm, glabrous, pericarp thin, apex acuminate, dehiscent into 10 segments, false septa partially developed, septa ciliated along the margins; seeds narrow to widely ovate, reddish-brown, 1.5–1.8 × 0.8–1.1 mm.

Distribution: —Endemic to Mexico, in Aguascalientes, Chihuahua, Coahuila, Durango, and Jalisco ( Fig. 5c ).

Habitat and ecology: —Oyamel fir forest, cypress-juniper forest, oak forests, oak-pine forests, thornless or small-leaved sub-thornless shrubland, palm-tree forests, pine forests. Elevation 1900–2900 m. Cambisol, Kastanozem, Phaeozem, Lithosol, Luvisol, Regosol, Rendzina, Vertisol, and Xerosol soil types.

Phenology: —Flowering in March–September; fruiting in June–October.

Note: —It is easily distinguished from other Mexican flax species by the white to pinkish color of the corolla; however, it is often confused with L. neomexicanum based on vegetative traits. The ovoid-pyriform fruits of L. pringlei are another character that can be used to identify the species.

Conservation status: — Linum pringlei registers an EOO of 229,843.785 km 2, and an AOO of 120 km 2. In addition, the species is known from> 10 localities therefore it is considered as LC. However, the species, besides being endemic, presents a not continuous distribution that affects the estimation of EOO. Furthermore, template forests of the high regions of Mexico as the north-western portion—the area of distribution of the species—are disappearing due to the development of agriculture and livestock ( Gutiérrez-Garcia & Ricker 2019, CONABIO 2021), so L. pringlei could be threatened in the short term.

Specimens examined: — MEXICO. Aguascalientes: San José de Gracia , 10 km al NW de la Congoja, 2630 m, 22°12’39.2”N, 102°38’5.9”W, 16 October 2013, Murillo-Pérez 525 ( INEGI!) ; San José de Gracia , 12 km al SW de la Congoja, 2700 m, 16 October 1973, Rzedowski & McVaugh 778 ( MEXU!) . Chihuahua: Ocampo, Parque Nacional, Cascada de Basaseachi , 2100 m, 28°11’00”N, 108°12’30”W, 3 October 1986, R Spellenberg et al. 8674 ( CIIDIR!) . Coahuila: Saltillo, Ladera caliza 3 km al S de El Frayle, 1953 m, 25°00’47.6”N, 101°20’6.8”W, 1 October 2016, M.A. Ayala-Ramos et al. 60 ( MEXU!) . Durango: Cuencamé, Cuencamé de Ceniceros , 12 October 1973, J. Marroquín 2648 ( ANSM!) ; Durango, Predio Las Bayas , 2710 m, 8 August 1990, A. García & M. González 569 (CHAPA!, CIIDIR!) ; Durango, Parque El Tecuán, 4 September 1984, F. Casillas et al. 38 ( CIIDIR!) ; Durango, Parque El Tecuán, 30 August 1984, F. Casillas et al. 40 (CHAPA!, IBUG!) ; Durango, Predio Las Bayas , 2700 m, 23°25’00”N, 104°51’00”W, 8 August 1990, A. García & M. González 605 ( CIIDIR!) ; Durango, Parque El Tecuán, 30 August 1984, F. Casillas et al. 40 ( CIIDIR!) ; Durango, Parque El Tecuán, 4 September 1984, F. Casillas et al. 39 ( CIIDIR!) ; Durango, Parque El Tecuán, 4 September 1984, F. Casillas et al. 46 ( CIIDIR!) ; El Mezquital, 19 km de Los Charcos , 2400 m, 4 October 1983, S. González & M. González 2560 (ANSM!, CHAP!, CHAPA!, CIIDIR!, IBUG!, MEXU!) ; El Mezquital, 22 km al NE de Los Charcos , 2750 m, 1 November 1982, S. González & J. Rzedowski 2345 (CHAPA!, CIIDIR!) ; El Mezquital, Rancho de La Mesa , 28 September 1985, I. Solís 391 (CIIDIR!, IEB!, MEXU!) ; Otaez, Entre Llano Blanco y San José de la Escalera, 5 October 1990, A. Benítez 2654 (CHAP!, CIIDIR!, MEXU!) ; Puente El Cajón San Antonio a 10 km de Altares, 1510 m, 2 October 1990, O. Bravo B. 1711 (CHAP!, CIIDIR!) ; Súchil, Trampa Las Iglesias a 2 km de Alemán, 19 September 1986, F. Acevedo 245 (ANSM!, CHAP!, CIIDIR!) ; Súchil, Potrero Tinajíta, ejido San Juan de Michis , 23 September 1985, J. Alvarado 60 (ANSM!, CHAPA!, CIIDIR!, IBUG!, IEB!) ; Súchil , 4 km al SW de Piedra Herrada, 2400 m, 11 September 1981, S. González 1948 (ANSM!, CHAPA!, CIIDIR!, ENCB!, IEB!, XAL!) ; Súchil, Arroyo El Ranchero , 2400 m, 23°22’03”N, 104°18’03”W, 12 August 1990, S. González & M. González 4751 (CIIDIR!, IBUG!) ; Súchil, Reserva de la Biosfera de La Michilia , 23°23’99”N, 104°14’99”W, 1 October 1983, G. Flores 13519 ( CIIDIR!) ; Súchil, Arroyo Las Iglesias , 12 September 1986, F. Acevedo 234 ( CIIDIR!) ; Súchil , Mesa EL Burro, 2700 m, 23°23’99”N, 104°17’99”W, 18 September 1985, S. González 3235 (CHAP!, CHAPA!; CIIDIR!, UAMIZ!) ; Súchil, Arroyo Los Indios , 19 September 1985, J. Alvarado 36 ( CIIDIR!) ; Tepehuanes , 50 km de Tepehuanes, 2570 m, 12 September 1989, O. Bravo B. 316 (CHAP!, CIIDIR!) ; Tepehuanes , 5 km de la Mesa Alta, 2450 m, 6 September 1989, O. Bravo B. 244 (CHAP!, CIIDIR!) ; 4 km al NW of Los Angeles along road between Mazatlan and Durango, 2500 m, 28 October 1973, D.E. Breedlove 35739 ( MEXU!) . Jalisco: Tequila, Cima del Cerro ( Volcán ) de Tequila, 2850 m, 8 October 1988, M. Cházaro B. et al. 5723 (IBUG!, IEB!) ; Mezquitic, 5 km al NE de El Mortero por el camino a Monte Escobedo , 2300 m, 22°22’00”N, 103°37’00”W, 22 September 2001, P. Carrillo-Reyes & E.M. Guevara 2677 ( IBUG!) .

Figures

FIGURE 5. Geographic distribution in the Mexican territory of:A. L. cruciata, L. lasiocarpum, L. lewisii, L. mexicanum, and L. tenellum; B. L. elongatum, L. neomexicanum, L. puberulum, L. rzedowskii, and L. schiedeanum; C. L. modestum, L. orizabae, L. pringlei, L. scabrellum, and L. vernale. Maps by Ma. Isabel Olivares.

FIGURE 9. A. Linum orizabae; B. Linum pringlei; C. Linum puberulum; D. Linum rupestre. Photographs by José Luis Colin.