Spigelia mocinoi S. Islas & L.O. Alvarado, 2017

Islas-Hernández, C. Sofia, García, Rubí Bustamante & Alvarado-Cárdenas, Leonardo O., 2017, New additions of Spigelia (Loganiaceae) in Mexico, Phytotaxa 331 (2), pp. 243-252 : 247

Spigelia mocinoi S. Islas & L.O. Alvarado sp. nov.

Type:— MEXICO, Estado de Mexico: Ixtapan, Temascaltepec, 18 July 1935, G.B. Hinton 8063 (Holotype: MEXU, Isotype: ENCB, HUMO). Fig. 2 .

Spigelia mocinoi is similar to Spigelia nicotianiiflora based on vegetative characters, but differs from the latter by its non-rhizomatous (vs. rhizomatous) plants, inflorescences with 3-5 flowers (vs. 8-9 flowers) and corolla lobes of 1.9-2 × 1 cm (vs. 0.9-1.6 × 0.4-0.5 cm).

Perennial erect herbs of 25–30 cm tall. Stems cylindrical, pilose, monopodial. Leaves opposite, sessile; stipules absent; blades 2.9–3.3 × 1.7–2.1 cm, ovate-lanceolate, base rounded, apex acute, membranaceous, adaxially pilose, abaxially glabrescent. Inflorescences terminal, in scorpioid cymes, with 3–5 flowers; peduncles 1.0- 1.5 mm long, pilose; pedicels 7.0- 7.5 mm long, glabrescent; bracts 2.4 × 0.75 mm, lanceolate, pilose, persistent; bracteole 1.0-1.5 x 0.5 mm, deltate, minutely ciliate, persistent. Calyces with sepals fused at the base only, lobes 14 × 3.0 mm, lanceolate, pilose, green. Corollas hypocrateriform, tube 10.0 × 1.5 cm, white, glabrate; lobes 2.0 × 1.0 cm, ovate, internally glabrate, externally ciliate, white inside and outside; stamens included, filaments 2.3 mm long, glabrate, inserted on the upper half of the corolla tube, anthers 4.0– 4.5 mm long, dorsifixed, lanceolate-sagittate, glabrate; pollen in monads, oblate-suboblate, tricolpate, tectate rugulate, gemmate and verrucose, with major density of verrucose and gems in the apocolpium and more rugulae in the mesocolpium, polar axis 52–77 μm, equatorial axis 69–90 μm; ovary 1.6 mm, globose, style 7.0–9.0 cm long, glabrescent, stigma 0.7–0.8 mm long, capitate, pilose. Capsules unknown, seeds unknown.

Etymology:— Spigelia mocinoi is dedicated to José Mariano Mociño (1757–1820), a remarkable Mexican botanist born in Temascaltepec, the place where the new species was found.

Habitat:—The new species can be found in tropical deciduous forest, at 1000 to 1300 m elevation, with annual precipitation of 800–1200 mm and average annual temperature of 20–29 °C (Rzedowski 2006, Challenger & Soberón 2008).

Distribution:—Species endemic to Mexico, restricted to the Estado de Mexico.

Phenology:—Flowering July to August. The fruiting period is still unknown.

Conservation:— Spigelia mocinoi is known only from the type locality in Temascaltepec, Estado de Mexico. The specimen was collected over 80 years ago. However, 68% of the territory of the municipality is preserved forest, so it is likely that the species is still occurring in the area. We propose to assign this taxon to the category of Data Deficient (DD) ( IUCN 2016).

Figures

FIGURE 2. Holotype of Spigelia mocinoi. Herbario Nacional de México (MEXU), Plantas Vasculares. Portal de Datos Abiertos UNAM (on line).