Linum usitatissimum Linnaeus 1753
Creators: name: González-Velasco, Juan
name: Burgos-Hernández, Mireya
name: Galván-Escobedo, Iris G.
name: Castillo-Campos, Gonzalo
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Malpighiales
Linaceae
Linum
Linum usitatissimum

description: Linum usitatissimum Linnaeus (1753: 277). (Fig. 10d).
Type:—Habitat hodie inter segetes, Europae australis. Herb. Clifford 114, Linum no. 1. (lectotype BM!).
Linum angustifolium Hudson (1778: 134).
Linum humile Miller (1768: 2).
Description:— Herbs, annual, 20–100 cm in height, glabrous, root thick; stems erect, smooth to simple striate, sometimes sparsely branched from the base, cylindrical, glabrous. Leaves entire, alternate, linear to linear-lanceolate, 10.0–40.0 × 0.7–3.0(4.0) mm, sessile, apex acute to acuminate, 1-nerved, scariose, glabrous, stipular glands absent. Inflorescence an open cymose panicle, glabrous; pedicels glabrous, 20-35 mm long; bracts 10.0–24.0 mm long, glabrous, margin entire, apex acute, stipular glands absent; sepals persistent, elliptical to ovate, 5–8 mm long, margin entire, thoroughly ciliated toward the apex or finely ciliate-fimbriate, scariose, apex acuminate, 1-nerved, stipular glands absent; petals blue, obovate, 9–15 mm long, glabrous; stamens 4.0–5.0(7.0) mm long; anthers (1.0)1.8–2.0 mm long, bright-yellow; staminodia absent; styles free or connate at the base, 3.0–6.0 mm long; stigmata linear or claviform, white. Fruit widely ovate to subglobose, yellow, 6–10 × 5–10 mm, glabrous, pericarp thick, apex rounded, dehiscent into 10 segments; false septa ciliated; seeds lanceolate, brown, 4.0–6.0 × 2.5–3.0 mm.
Distribution: —Native of Europe and Asia (India, Eastern Mediterranean and Near East). Introduced in America, in Canada, United States of America; in Mexico, in Coahuila, State of Mexico, Jalisco, Michoacan, Nuevo Leon, and Sonora (Fig. 2b); to South America; in Asia (far East), South Africa, and Australia.
Habitat and ecology: —Ruderal and cropland. Elevation 1900–3000 m. Limestone Andosol, Cambisol, Phaeozem, Planosol, Regosol, and Vertisol soil types.
Phenology: —Flowering and fruiting throughout the year.
Note: —This blue-flowered species can easily be confused with L. lewisii; however, the size of the plant, leaves, and fruits are larger in L. usitatissimum. Besides, the linear to claviform styles, as well as its habitat, are key characters for differentiating the species.
Conservation status: — Linum usitatissimum is the only species of the family in Mexico that is introduced and naturalized. It is considered a crop, ruderal and weed species (Martínez-Orea et al. 2020).
Specimens examined: — MEXICO. Coahuila: Saltillo, Invernadero UAAAN Buenavista, 1750 m, 25°21’25”N, 101°02’04”W, 13 May 1986, L. Arce 288 (ANSM!). State of Mexico: Texcoco, 2240 m, 19°29’28”N, 98°52’47”W, 14 August 1976, S.D. Koch 76151 (CHAPA!); Texcoco, Campo Experimental Chapingo, 2250 m, 19°29’00”N, 98°53’00”W, 11 October 1984, G. Vázquez C. 33 (CHAPA!); Villa Guerrero, Entre el Pueblo y la Autopista, 2267 m, 18°59’20.3”N, 98°38’53.9”W, 6 October 2000, H. Vibrans 6781 (CHAPA!). Jalisco: Chapala, Carretera Ocotlán-Atequiza, 1500 m, 20°19’38”N 103°11’08”W, 20 May 1968, L.M.V. de Puga 2727 (IBUG!); Ocotlán, 20°20’45”N, 102°46’12”W, 1 April 1973, J. Fdo. Amador A. 25 (IBUG!); Tepatitlán, 20°48’26”N, 102°46’07”W, 1 December 1977, T. Tejeda 135146 (IBUG!); Zapopan, Villa Universitaria al W de Guadalajara, 1550 m, 20°41’47”N, 103°24’47”W, 15 March 1975, L.M.V. de Puga 17066 (IBUG!). Michoacan: Pátzcuaro, Salida a Uruapan, 2100 m, 19°29’36”N, 101°36’00”W, 20 September 1993, J.M. Escobedo 2649 (IEB!). Nuevo Leon: Galena, Cerro el Potosí cerca de San José de la Joya, 3200 m, 24°53’12.8”N, 100°14’28.6”W, 24 September 2011, E. Estrada et al. 20955 (ANSM!). Sonora: Cajeme, Distrito Guaymas, 28°05’26”N, 110°00’47”W, 18 May 1957, J. Corral 44 (CHAPA!).
description: Published as part of González-Velasco, Juan, Burgos-Hernández, Mireya, Galván-Escobedo, Iris G. & Castillo-Campos, Gonzalo, 2022, Taxonomic update of the flax family in Mexico, pp. 141-184 in Phytotaxa 549 (2) on pages 175-176, DOI: 10.11646/phytotaxa.549.2.3, http://zenodo.org/record/6622753