Dictyanthus nichongus

Distribution & habitat: — Dictyanthus nichongus is only known from two localities in Jalisco. One of them is the population of the type specimen collected in Chalacatepec deciduous forest; the second locality corresponds to photographs posted on social media (Fig. 1 A, 3 A) from the locality of Tenamaxtlan, Municipality of Tenamaxtlan, for which we have no further information. The area of Chalacatepec belongs to the Pacific Coastal Plain, a physiographic region of Jalisco, Mexico. The new species is scarce and no more than 50 individuals were observed in the area. The population can be found between 20 and 45 m elevations. We observed a fly, probably Sarcophagydae, visiting the flowers, but we did not observe if the pollinaria were carried out, nor did we perceive an odor from the flower at the time (Fig. 1. D). Phenology: — The specimen were collected with flowers and fruits in June. Provisional conservation assessment: — The individuals of this species are restricted to Jalisco, Mexico, and two populations are known; one from the type locality close to the Chalacatepec beach, Jose Maria Morelos, Municipality of Tomatlan (Fig. 1 B-D, 2, 3 B), and the second from an observation, recorded only by photographs, in the locality of Tenamaxtlan, Municipality of Tenamaxtlan, Jalisco (Fig. 1 A, 3 A). According to the people of José María Morelos, a hotel project is about to be carried out in the region, which could impact negatively on the vegetation where the population of Dictyanthus nichongus grows. The information about its population, phenology, and distribution is scarce, and the imminent habitat fragmentation and land-use change could place the plant populations at risk. Considering that we only know data from the type locality, together with the anthropogenic impact, we suggest the category of Critically Endangered B 2 ab (ii) according to the red list criteria of the IUCN (2019). Notes: — Dictyanthus is a morphologically interesting genus due to their flowers with a reticulated pattern of colors, sacciformed corollas, palmatilobed gynostegial corona with diverse morphology and fused to the corolla. This new species highlights Mexico as a center of diversity (17 spp.) and endemism for the genus (88 %). Additionally, Dictyanthus nichongus increases the number of species of the genus in Jalisco to eight (Fig. 3), which places it, along with Oaxaca, the state with the highest diversity of Dictyanthus (Alvarado-Cárdenas et al. 2020). The individuals of D. nichongus are distinct from all known species of the genus, but show some similarity with those in D. macvaughianus (Stevens 1988). Both species have corollas with pronounced sacs between the corona, with mainly parallel lines, and the stylar head apex is convex (Fig 3 A – B, D). Dictyanthus nichongus has a flower diameter of 1.8 ‒ 2.0 cm, yellowish to almost purple with purple lines, rhombus-shaped corona lobes, and reddish to purple stylar head apex exserted from the corolla tube (Fig 1, 2). While D. macvaughianus has a flower diameter of 3 cm, brownish with purple to gray lines, linear-spatulate corona lobes, and the stylar head apex is pink and included in the corolla tube (Stevens 1988; Fig 3 D). Dictyanthus parviflorus shares some similarities with D. nichongus in their campanulaterotate flowers with pronounced sacs between the corona lobes (Fig 3 E). The former differs by its reticulate pattern in the corolla tube, linear-lanceolate gynostegial corona, and its gynostegium and stylar apex included in the corolla. Dictyanthus tuberosus showed some resemblance with the new species in its small and purple flowers with parallel lines in the corolla tube. It differs by its campanulate corolla, and gynostegium and stylar head apex deeply included in the corolla (Fig 3 I).