Linum lasiocarpum Rose 1909
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 lasiocarpum

description: Linum lasiocarpum Rose (1909: 274). (Fig. 6c).
Type:— MEXICO. Nuevo Leon, near Monterrey, Pringle 10209 (holotype US!, isotypes CM, F, GH!, MICH, MO, MSC, NY!, UC!).
Description: — Herbs, annual, 15–40 cm in height, glabrous, root thin; stems slightly decumbent, extending toward the inflorescence, branched from the base, glabrous. Leaves entire, basal leaves arranged in whorls of 4, narrowly oblanceolate to obovate; distal leaves opposite and alternate, narrowly elliptical; (4.0)6.0–23.0 × 1.7–6.8 mm, subsessile, apex obtuse; 1-nerved, nervation more evident in the abaxial surface; occasionally rough hairs near leaf nodes and bases, prominent stipular glands present at the base. Inflorescence a cymose panicle, branched, occupying more than half the plant height; pedicels 0.8–2.1 mm long, villous; bracts 2.2–4.1 mm long, margin glandular-dentate, apex acute, prominent stipular glands present at the base; sepals persistent, lanceolate, 1.7–2.5 × 0.5–1.0 mm, marginal glands conspicuous, sessile, apex acute to acuminate, 3-nerved, stipular glands present; petals yellow, narrowly obovate, 3.0– 4.0 mm long, glabrous; stamens 2.0–3.0 mm long; anthers 0.5 mm long, light yellow; staminodia minute; styles free, 2.0 mm in length; stigmata capitate, light yellow. Fruit widely ovoid, yellow, 1.2–2.1 × 1.3–2.0 mm, sparsely hirsute at the mid portion, pericarp thin, apex acute, dehiscent into 10 segments, false septa poorly developed, true septa with some marginal hairs; seeds ovate, light brown, 0.9-1.2 × 0.6-0.7 mm.
Distribution: —Endemic to Mexico, in Coahuila, Nuevo Leon, and Tamaulipas (Fig. 5a).
Habitat and ecology: —Oak forests, oak-pine forests, grasslands. Elevation 600–2100 m. Kastanozem, Phaeozem, Lithosol, Vertisol, and Xerosol soil types.
Phenology:—Flowering and fruiting in March–June.
Note: —Although the prominent stipular glands at the base of leaves and bracts and the villous pedicels clearly separate L. lasiocarpum from other northern species such as L. aristatum, L. berlandieri var. filifolium, L. elongatum, L. flagellare, L. modestum, L. puberulum, this is not the case with its closest species, L. nelsonii. However, the nerves on the leaf under surface, the marginal glands of sepals, and the pointed and hirsute fruits, together allow clearly separating L. lasiocarpum from L. nelsonii.
Conservation status: —According to the criteria established by the IUCN (2019) L. lasiocarpum is EN (B1 + 2ac(iii)), with an EOO <20,000 km 2 (2,369.840 km 2) and AOO of 28 km 2. The species is restricted to a few states in the Northeast of Mexico.
Specimens examined: — MEXICO. Coahuila: Castaños, Sierra La Gavia, 1351 m, 26°19’60”N, 101°15’00”W, 12 May 1992, M.H. Mayfield et al. 1321 (TEX!). Nuevo Leon: Galeana, 6 km E of Potosí, 2100 m, 3 July 1984, Hinton et al. 18725 (CHAPA!); Montemorelos, El Pastor, 845 m, 19 May 1994, Hinton et al. 24232 (ANSM!, CIIDIR!, IEB!, MEXU!); Monterrey, Northwestern outskirts of Monterrey, 29 March 1973, C.M. Rogers 13455 (MEXU!); Monterrey, Foothills of the Sierra Madre, 610 m, 15 April 1906, C.G. Pringle 10209 (MEXU!); Santiago, La Nogalera, 950 m, 16 June 1994, Hinton et al. 24409 (ANSM!, IEB!); Santiago, Cola de Caballo, 800 m, 25°23’00”N, 100°10’00”W, 20 June 1984, J.A. Villarreal & M.A Carranza 2778 (ANSM!); Santiago, El Manzano, 1600 m, 19 May 2004, E. Estrada et al. 16139 (ANSM!). Tamaulipas: San Carlos, Sierra de San Carlos, 1134 m, 24°31’00”N, 98°57’01”W, 17 June/ 1987, G. Nesom et al. 6053 (TEX!).
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 154-155, DOI: 10.11646/phytotaxa.549.2.3, http://zenodo.org/record/6622753