Spigelia ayotzinapensis L.O. Alvarado, S. Islas & R. Bustamante, 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 : 244

Spigelia ayotzinapensis L.O. Alvarado, S. Islas & R. Bustamante sp. nov.

Type:— MEXICO, Guerrero: Chilapa de Álvarez, Parque Nacional General Juan N. Álvarez, 17°35’46.3” N, 99°5’9.8” W, 31 July 2010, R. Bustamante, et al. 414 (holotype FCME!, isotype MEXU!). Fig. 1 .

Spigelia ayotzinapensis is similar to Spigelia mocinoi because of its sessile, ovate-lanceolate leaves without stipules. The former can be easily distinguished by its quadrangular (vs. cylindrical) stems, chartaceous (vs. membranaceous) leaves, monochasium with 1-2 flowers (vs. scorpioid cyme with 3-5 flowers), sepals green with purple apex (vs. sepals green) and white corolla with purple apex (vs. white corolla).

Perennial erect herbs of 10–20 cm tall. Stems quadrangular, pilose, monopodial. Leaves opposite, sessile; stipules absent; blades2.9–3.3 × 1.5–2.6 cm, ovate-lanceolate to elliptic, base rounded to attenuate, apex acuminate, chartaceous, adaxially and abaxially glabrate. Inflorescences terminal, one-sided cyme (monochasium), with 1–2 flowers; peduncles subsessile or less than 0.5 mm long, glabrescent; pedicels 3.9 mm long, pilose; bracts 1.0 × 0.9 mm, lanceolate, glabrate, persistent; bracteole absent. Calyces with sepals fused at the base only, lobes 10–13 × 0.7–1.3 mm, lanceolate, glabrate, green with purple apex. Corollas hypocrateriform, tube 8.0–10.0 × 1.2 cm, white, glabrescent; lobes 1.7–2.5 × 1.0– 1.3 cm, ovate-lanceolate, internally and externally glabrate, white inside, white with purple margin outside; stamens included, filaments 3.0– 3.3 mm long, glabrate, inserted on the upper half of the corolla tube, anthers 4.0 mm long, basifixed, lanceolate-sagittate, glabrate; pollen in tetrahedral tetrads, prolate-spheroidal to oblate-spheroidal, tetracolpate, tectate microrugulate, foveolate, homogeneously distributed in the apocolpium and the mesocolpium, polar axis 50–75 μm, equatorial axis 70–90 μm; ovary 1.6 mm, ovoid, style 4.8–6.5 cm long, glabrescent, stigma 1.29 mm long, capitate, pilose. Capsules unknown, seeds unknown.

Etymology:— Spigelia ayotzinapensis is named in honor of the 43 missing students, nine dead and 27 wounded, from the Escuela Normal Rural Raul Isidro Burgos in Ayotzinapa, Guerrero, Mexico on September 26–27, 2014. We are all Ayotzinapa. ¡Vivos se los llevaron, vivos los queremos!

Habitat:—The new species can be found in Quercus forest, at 2078 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 state of Guerrero.

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

Conservation:— Spigelia ayotzinapensis is known only from the type locality, recorded in the central-east of the state of Guerrero.The population was collected close to the municipality of Chilapa de Álvarez.Although the population seems abundant and the area surrounding the municipality is still conserved, the specimen was collected seven years ago and the locality is currently severely affected by livestock. We suggest assigning the category of critically endangered (CR) for this taxon ( IUCN 2016), due to the very restricted area of distribution and the anthropogenic impact of the type locality.

Figures

FIGURE 1. Holotype of Spigelia ayotzinapensis.