Linum scabrellum Planchon (1848d: 507)

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 : 170-171

Linum scabrellum Planchon (1848d: 507) . ( Fig. 11 ).

Type:— MEXICO. Hidalgo: Zimapán, T. Coulter 754 (holotype K!) .

Cathartolinum scabrellum Small (1907c: 74) .

Linum macradenium Brandegee (1911: 181) . Type:— MEXICO, San Luis Potosi, Minas de San Rafael , Purpus 4923 (holotype UC!, isotype F, GH!, MO!, US) .

Description: — Herbs, perennial, up to 50 cm in height, pubescent to densely pubescent, root thick; stems erect, ascending, striate, branched from the base, sometimes simple, covered with rigid, whitish, conspicuous hairs. Leaves entire, occasionally with marginal glands in the upper leaves; basal leaves opposite, distal leaves alternate; linear, linearlanceolate, inferior leaves occasionally elliptical, 5.0–17.0 × 1.0– 3.5 mm, sessile, apex acute to acuminate, 1-nerved, coriaceous, pubescent; black stipular glands present at the base, very conspicuous. Inflorescence a cymose panicle, pedicels (5.9)10.0–20.0 mm long; bracts 2.5–7.1 mm long, pubescent along the central nerve, margin glandular-dentate, apex acuminate; black stipular glands present at the base, very conspicuous; sepals persistent, lanceolate to narrowly ovate, 2.5–5.5(6.0) × 1.0– 2.2 mm, margin glandular-dentate; apex acute to acuminate, occasionally with purple hues; 3-nerved, central nerve evident; stipular glands two, black, present at the base, very conspicuous; petals yellow-orange, oblanceolate, 4–10 mm long, pilose at the base; stamens 4–7 mm long, glabrous or sparsely pilose; anthers 0.4–1.2 mm long, yellow; staminodia minute, sometimes absent; styles free, 2.5–6.5 mm long; stigmata capitate, yellow. Fruit ovoid to subglobose, yellow, 2.5 × 2.5–4.0 mm, glabrous, pericarp thick, apex acute, dehiscent into 10 segments, false septa partially developed, septa ciliated; seeds elliptical to ovate, reddish-brown, 1.5–2.0 × 1.0 mm.

Distribution:—Endemic to Mexico, in Aguascalientes, Guanajuato, Hidalgo, Nuevo Leon, Oaxaca, Puebla, Queretaro, San Luis Potosi, and Veracruz ( Fig. 5c ).

Habitat and ecology: —Cypress-juniper forest, cardonal shrublands, chaparral shrubland, crassi-rosette-leaved thorny shrublands, oak forest, oak-pine forest, yucca shrublands, thorny shrubland, thornless or sub-thornless smallleaved shrubland, pine forests, grasslands, low deciduous tropical forest, low deciduous thorny tropical forest, sandy arid desert vegetation. Elevation 1400–2950 m. Cambisol, Kastanozem, Phaeozem, Fluvisol, Lithosol, Luvisol, Regosol, Rendzina, Vertisol, and Xerosol soil types.

Phenology: —Flowering in March–December; fruiting in June–December.

Note: —This is the only species in Mexico that is pubescent throughout all its vegetative parts, with no leaves in whorls and with free styles. It is morphologically similar to L. rupestre , but the latter is entirely glabrous. It was observed that the specimens of L. scabrellum collected in localities further north of its distribution range are slightly less densely pubescent than those from central and southern Mexico; it is possible that Rzedowski and Calderón de Rzedowski (1992) refer to this character when they describe these plants as “ cinereas ” (i.e. whitish-looking).

Conservation status: — Linum scabrellum is a species with a wide distribution range and according to the criterion B and subcriteria established by the IUCN (2019), this species can be considered as LC (EOO = 186,173.234 km 2). However, taking into account its AOO of 140 km 2 and the expansion of mining and ranching activities in its distribution area ( Salinas-Rodríguez 2015, De Nova et al. 2019), the species could see its populations threatened in the short term.

Specimens examined: — MEXICO. Aguascalientes: Tepezalá, Extremo NE deArroyo Hondo , 2000m, 22°11’05”N, 102°11’13”W, 1 November 2007, G. García 5386 ( IEB!) ; Tepezalá , 4 km al E de Tepezalá, 2247 m, 22°13’13.1”N, 102°08’6.1”W, 19 April 2013, G. García R. 6015 ( INEGI!) . Guanajuato: Atarjea, Puerto del Gallo, 8 km al Sureste de La Joya , 2100 m, 14 December 1988, E. Ventura & E. López 6501 ( XAL!) ; San Luis de la Paz, 5 km al S de Pozos , 2100 m, 24 September 1994, Rzedowski 52586 (ANSM!, XAL!) ; San Luis de la Paz, cerca de El Pregón, 24 September 1994, Rzedowski 52569 (IEB!, XAL!) ; 3 km al W de Pozos , 2300 m, 28 June 1987, Rzedowski 43481 ( XAL!) . Hidalgo: Nicolás Flores, El Arenalito , 20°46’04”N, 99°68’56”W, 20 September 1995, V.H. López B. 134 (CHAP!, XAL!) . Nuevo Leon: Aramberri, Cerro Grande , 2180 m, 19 October 1986, Hinton et al. 19106 (CHAPA!, CIIDIR!, IEB!) ; Dr. Arroyo, Carretera Matehuala-Dr. Arroyo aprox. 38 km, 17 June 1992, J.A. Villarreal & M.A. Carranza 6555 ( ANSM!) ; Dr. Arroyo, Santa Gertrudis, nr., 1780 m, 16 March 1993, Hinton et al. 22707 ( ANSM!) ; Dr. Arroyo, Camino a Agua Nueva , 2000 m, 23 June 1981, O. Briones 683 (ANSM!, XAL!) ; Galeana, Santa Gertrudis , 1700 m, 20 July 1993, Hinton et al. 23043 ( IEB!) ; Mier y Noriega, West of Refugio de Cerros Blancos , 1825 m, 1 October 2001, Hinton et al. 27692 ( ANSM!) . Oaxaca: Cuicatlán , 6 km al N de Cuicatlán, 1750 m, 19August 1987. A. Salinas T. et al. 4323 ( XAL!) ; 2 km al NE-E de Suchixtlahuaca , 2100 m, 17°43’00”N, 97°21’00”W, 6 June 1985, F. Chiang et al. 2519 (MEXU!, XAL!) . Puebla: Cañada Otate, brecha a Hijaderoaria , 2121 m, 18°01’00”N, 97°20’00”W, 5 November 2001, P. Tenorio L. & L. Kelly 21561 ( MEXU!) ; Hwy 28, N of Azumbilla (which is N of Tehuacan ), 2375 m, 18°41’00”N, 97°24’20”W, 16 July 1991, Mayfield et al. 876 ( MEXU!) . Queretaro: Peña Miller, Ejido Maguey Verde , 2242 m, 21°05’21”N, 99°41’45”W, 13 October 2005, O. Mares A. & M. Sosa M. 497 ( ANSM!) ; Cadereyta, Alrededores de Maconí , 1800 m, 10 November 1988, Rzedowski 47642 ( ANSM!) ; Ezequiel Montes, Cerro La Caja frente a la Peña de Bernal , 2157 m, 20°44’38.2”N, 99°55’49.3”W, 24 September 2020, J. González-Velasco & P. Albarrán-González 20001 ( CHAPA!) ; San Joaquín, Cañada La Culebra , 1600 m, 27 August 1978, S. Zamudio 3221 ( CIIDIR!) ; 5 km al S de Vizarrón , 16 August 1989, Rzedowski 48673 ( CIIDIR!) ; Cadereyta, Alrededores de Maconí , 1800 m, 10 November 1988, Rzedowski 47642 ( IBUG!) ; San Joaquín, Cañada La Culebra , 1600 m, 27 August 1978, S. Zamudio R. 3221 (IBUG!, XAL!) ; Tequisquiapan , 3 km al W de Las Rosas, 2000 m, 8 September 1990, Rzedowski 49998 ( XAL!) ; Ezequiel Montes, 7.5 km de Bernal, carretera a Tolimán , 2000 m, 20°46’22”N, 99°54’14”W, 11 October 2008, E. Carranza & I. Silva 7493 ( IEB!) ; Peñamiller, Camargo , 1700 m, 12 June 1991, E. Ventura & E. López 9229 ( IEB!) ; Ezequiel Montes, 7.5 km de Bernal, carretera a Tolimán , 2000 m, 20°46’22”N, 99°54’14”W, 11 October 2008, E. Carranza & I. Silva 7493 ( UAMIZ!) ; Peñamiller, Camargo , 1700 m, 12 June 1991, E. Ventura & E. López 9229 ( XAL) . San Luis Potosi: Ahualulco, 9.7 km al W del entronque Ahualulco-Charcas , 2100 m, 10 October 1985, F. García-Pérez 2025 (ANSM!, INEGI!, SLPM!) ; Armadillo de los Infante, Sierra de Álvarez , 1800 m, 1 September 2012, F. García S. 8640 (ANSM!, SLPM!) ; Armadillo de los Infante, Camino a Tlaxcalilla a 200 m del cruce con la carretera con dirección a la mina, 1711 m, 22°16’0.67”N, 100°40’13.6”W, 10 September 2020, A. Villalvazo-Hernández & J. González-Velasco 44 ( CHAPA!) ; Charcas , 6 km al E de Miguel Hidalgo, 23°12’00”N, 101°04’00”W, 7 July 1985, P. Tenorio L. & T.P. Ramamoorthy 9208 ( MEXU!) ; Guadalcazár, Km 9 carretera a Guadalcazár , 1635 m, 22°37’19.3”N, 100°29’26”W, 11 September 2020, A. Villalvazo-Hernández & J. González-Velasco 49 ( CHAPA!) ; Guadalcázar , 1.6 km al este de la carretera Matehuala-San Luis Potosí, 1609 m, 9 November 2019, V.W. Steinmann & M.M. Salinas-Rodríguez 8249 ( CHAPA!) ; Guadalcázar , El Cañón Hondo, 12 km al NW de Guadalcázar, 22°36’58”N, 100°29’21”W, 16 November 1996, R. Torres C. 14852 ( IEB!) ; Guadalcazár , El Cañón Hondo, 12 km al NW de Guadalcazár, 22°36’58”N, 100°29’21”W, 10 October 1996, R. Torres C. 14698 ( IEB!) ; Real de Catorce , 18 km del entronque Matehuala-San Luis Potosí, 1850 m, 23°50’00”N, 101°05’00”W, 5 June 1990, J.A. Villarreal et al. 5734 (ANSM!, IBUG!) ; Real de Catorce, Camino a Real de Catorce sobre la loma que está antes de entrar al pueblo, 2537 m, 23°26’26.5”N, 100°48’59”W, 12 September 2020, A. Villalvazo-Hernández & J. González-Velasco 52 ( CHAPA!) ; Real de Catorce, Parte alta del cerro Quemado , 2910 m, 23°40’21”N, 100°54’45”W, 25 August 2013, S. Zamudio R. 16411 ( IEB!) ; Soledad Diez Gutiérrez , 5 km al NE de Laguna Seca, 2000 m, 30 August 1955, Rzedowski 6293 ( SLPM!) ; Villa Guadalupe, Sierra del Catorce rumbo a los lomeríos, 1833 m, 23°26’26.5”N, 100°48’59.6”W, 12 September 2020, A. Villalvazo-Hernández & J. González-Velasco 51 ( CHAPA!) ; Villa Juárez, Camino Guaxcamá-Buenavista con dirección a la mina, 1215 m, 22°15’49.6”N, 100°39’38”W, 11 September 2020, A. Villalvazo-Hernández & J. González-Velasco 45 ( CHAPA!) . Veracruz: Perote , ladera de cerro, 2400 m, 19°33’47.17”N, 97°13’47.17”W, 19 December 1998, G. Castillo-Campos 19095 ( MEXU!) .

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 11. Linum scabrellum. A. Aspect general of the plant; B. Leaf; C. Flower; D. Filament and anther; E. Styles and stigmata; F. Fruit; G. Detail of stipular glands and bracts; h. Leaf midrib detail. Illustrated by Lizbeth Pérez Lucas, based on J. González-Velasco & P. Albarrán-González 20001.