Linum rzedowskii Arreguin 1985
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 rzedowskii

description: Linum rzedowskii Arreguín (1985: 262). (Fig. 10a).
Type:— MEXICO, State of Mexico: Llano Pinahua, approximately 8 km SW from Rio Frío, municipality of Ixtapaluca, 3200 m, in a clearing in the middle of the pine forest, J. Rzedowski 37285 (holotype ENCB!).
Description: — Herbs, perennial, 15–25 cm in height, glabrous, root thick; stem creeping or prostrate, slightly striate, branched from the base, glabrous. Leaves entire, alternate, linear-lanceolate, (3.0–)4.6–5.5(–10.0) × (1.0–)1.1–1.3(– 2.0) mm, sessile, apex acuminate; 1–3-nerved, central nerve evident; coriaceous, glabrous, stipular glands absent. Inflorescence racemose, pedicels (4.5) 6.9–10.6 mm long, glabrous; bracts 2.1–4.2 mm long, margin entire, apex acute, stipular glands absent; sepals persistent, ovate, 3.0–4.0 × 2.0–3.0 mm, shorter than the capsule; margin white, scariose; apex acute; 1-3 nerved, barely evident lateral nerves; glabrous, stipular glands absent; petals blue, obovate, 6.0–8.0(11) mm long, glabrous; stamens 2.4–4.2 mm long; anthers 0.6–1.0 mm long, yellow; staminodia minute; styles free, 1.1–1.9 mm long; stigmata capitate, yellow. Fruit ovate, yellow, 5.0–6.0 × 4.0–5.0 mm, glabrous, pericarp thick, apex acute, dehiscent into 10 segments; septa ciliate; seeds elliptical, brown, 3.0–4.0 × 1.2–1.5 mm.
Distribution: —Endemic to Mexico, in the State of Mexico (Fig. 5b).
Habitat and ecology: —Grasslands, pine forests, low deciduous tropical forest. Elevation 3000–3500 m.Andosol, Cambisol, Phaeozem, Planosol, Regosol, and Vertisol soil types.
Phenology: —Flowering and fruiting in July–August.
Note: —This blue-flowered species occurs only in a small area of the State of Mexico; its distribution does not overlap that of L. lewisii. The creeping habit, the white margins of sepals, and the size of petals support an easy differentiation.
Conservation status: —Although, according to the B1 criterion established by the IUCN, L. rzedowskii can be considered Critically Endangered (CN) (EOO = 24 km 2), due to its AOO of 24 km 2 and a number of known localities, together with the degradation of its habitat adjacent to the largest human population nuclei by deforestation and tourism (Pineda-Jaimes et al. 2009, CONABIO 2021), this species is considered EN (B1 + 2abc(iii)).
Specimens examined: — MEXICO. State of Mexico: Chalco, Río Frío Estación Forestal Zoquiapan, 3500 m, 16 August 1974, E. García M. et al. 1256 (CHAPA!); Ixtapaluca, Estación Experimental de Investigación y Enseñanza de Zoquiapan 8 km al S de Río Frío, 3250 m, 04 July 1975, S.D. Koch 75289 (CHAP!, CHAPA!); Ixtapaluca, Estación Experimental de Investigación y Enseñanza de Zoquiapan 8 km al S de Río Frío, 3000 m, 28 August 1975, S.D. Koch & J. Magaña M. 75471 (CHAPA!); Ixtapaluca, Estación Experimental de Investigación y Enseñanza de Zoquiapan 8 km al S de Río Frío, 3200 m, 30 October 1975, S.D. Koch 75704 (CHAPA!); Ixtapaluca, Estación Experimental de Investigación y Enseñanza de Zoquiapan 8 km al S de Río Frío, 3200 m, 3 July 1978, R. Vega A. 229 (CHAPA!); Ixtapaluca, Llano Pinahua, 3250 m, 12 August 1980, Rzedowski 36790 (CIIDIR!, IEB!, SLPM!); Ixtapaluca, Llano Grande, 3000 m, 30/August/1983, E. Ventura V. 1295 (IEB!, XAL!); Ixtapaluca, Llano Tepochaico, 3350 m, 17/July/1983, Rzedowski 38109 (IEB!, XAL!); Ixtapaluca, Llano Grande, 3100 m, 3 July 1983, E. Ventura V. 1051 (UAMIZ!).
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 169-170, DOI: 10.11646/phytotaxa.549.2.3, http://zenodo.org/record/6622753