Lamourouxia gracilis Robinson & Greenman. Amer. J. Sci. Arts, 1895

Francisco-Gutiérrez, Antonio, Ruiz-Sanchez, Eduardo, González, Dolores & Lira-Noriega, Andrés, 2023, Lamourouxia (Orobanchaceae) of Mexico, Phytotaxa 582 (1), pp. 1921-1935 : 1921-1935

7. Lamourouxia gracilis Robinson & Greenman. Amer. J. Sci. Arts , ser. 3, 50: 174. 1895 Lectotype designated here:— MEXICO. Guerrero: Summit of Sierra Madre near Chilpancingo , 9000–12000 ft, 24 December 1894, E.W. Nelson 2234 (Lectotype: US00125700!; isolectotype: GH00078575 !)

Figure 7 A–E .

Herbs 25–60 cm tall, stems branched at base, reclining, woody, glabrescent, non-glandular. Leaves sessile, elliptic to obovate, 15–28 × 3–10 mm, margin serrate to crenate slightly revolute, 5–7 teeth each side, teeth 0.5–1 mm long; apex obtuse, base attenuate; membranous, glabrous to glabrescent, non-glandular. Inflorescence a raceme, erect, pedicels claviform, 6–12 mm long. Bracts equal along inflorescence, sessile, linear-spatulate to elliptic, 4–10 × 3–5 mm, margin serrate to crenate, 4–7 teeth per side in the upper half, apex obtuse, base attenuate. Calyx campanulate without dots on the surface, 5–10 × 3–6 mm, lobes elliptic to oblanceolate, 2–5 × 2–3 mm, margin crenate to crenulate, 2–5 teeth each side, apex obtuse, narrow at base, glabrous. Corolla tubular, 35–50 × 8–10 mm, upper lip 14–22 mm, lower lip 10–20 mm long, lobes 3–4 × 1.5–2 mm; brilliant fuchsia, pubescent, non-glandular. Stamens exserted 2, filaments of lower pair 30–45 mm, anthers 2 mm long, filaments of upper pair not seen. Style 30–35 mm long. Stigma capitate. Capsule ovoid to globose, 10–12 mm long, glabrous. Seeds not seen.

Etymology: —The epithet gracilis means thin.

Distribution and Ecology: —This species is endemic from Mexico and is distributed in the states of Guerrero and Morelos ( Fig. 7E ). It was collected in the transition and border of cloud forests and pine forests, at elevations from 1980 to 2170 m. This species is difficult to locate in the herbaceous substrate; the tiny leaves are easily camouflaged with other species. The brilliant fuchsia color of the flowers helps to identify it ( Fig. 7D ).

Phenology: —Flowers and fruit can be found from September to December. Most collected specimens are reported from September (three of five collections).

Nomenclatural notes: —The original description of Lamourouxia gracilis ( Robinson & Greenman 1895) cited the specimen Nelson 2234 without herbarium location. Ernst (1972) cited duplicates of this collection in GH and US as type specimens. Because of this, lectotype and isolectotype were designated here.

Examined specimens: — MEXICO. Guerrero: Chilpancingo , 1400 m, 24 December 1894, Nelson 2234 (US!, GH!). Morelos: Cuernavaca, Carretera de subida a Chalma , 2172 m, 12 October 2019, Francisco-Gutiérrez & RamírezMartínez 256 (IBUG!, MEXU!, XAL!); Lomas de Atzingo , August–September 1950, Lyonnet 5008000028 (MEXU!); mossy cliffs of wet barranca above Cuernavaca , 18 September 1986, Pringle 6510 (BR, CAS, ENCB!, F, G, GH, K, MEXU!, MO!, MSC, P!, PH, UC, US!, W); barranca La Tilapeña, junto a la antigua vía del tren y el túnel, 2036 m, 10 September 2016, Zamudio et al. 17150 (MEXU!).

Figures

FIGURE 7. Lamourouxia gracilis. A) Inflorescence. B) Leaves. C) Immature infructescence. D) habit. E) Distribution map. Lamourouxia integerrima. F) Inflorescence. G) Leaves. H) Distribution map. Credits in Appendix I.