Two new species of endemic Ecuadorean Amaryllidaceae (Asparagales, Amaryllidaceae, Amarylloideae, Eucharideae)

Abstract New species of the genera Stenomesson and Eucharis (Amaryllidaceae) are described from Ecuador. Stenomesson ecuadorense is the second species of the genus reported from that country, and the only endemic one. It is related to Stenomesson miniatum and Stenomesson campanulatum, both from Peru, with which it shares orange flower color and the fusion of the staminal corona to the perianth tube. It differs from Stenomesson miniatum by the non-urceolate perianth, from Stenomesson campanulatum by its shorter stamens and longer perianth, and from both by its lower montane, cloud forest habitat. Eucharis ruthiana, found in the vicinity of Zamora, is related to Eucharis moorei from which it differs by the narrower leaves and tepals; short, deeply cleft staminal corona; the long teeth on either side of the free filaments; the narrowly subulate, incurved free filaments; and the shorter style. The green mature fruit and campanulate floral morphology place it in Eucharis subg. Heterocharis.


Introduction
Ecuador is a major center of diversity for the Andean tetraploid clade of American Amaryllidaceae, specifi cally genera in the tribe Eucharideae (Meerow 1990), a monophyletic group characterized by pseudopetiolate leaves and the loss of the gene ndhF from the plastid genome (Meerow 2010;Meerow et al. 2000). In this paper, we describe two new species in the tribe, Stenomesson ecuadorense, and Eucharis ruthiana, both endemic to Ecuador.

Materials and methods
No specimens matching these new species were observed in herbarium collections in Ecuador (with the exception of the single specimen cited below under S. ecuadorense) housed at QCA, QCNE, HUTI, nor encountered by the fi rst author in collections examined over the past 30 years at GB, K, MO, and NY.
Ovary ellipsoid, ca. 6.7 mm long, ca. 3.2 mm wide, ovules 20 or more per locule, axile in placentation. Mature fruit (Fig. 1H) a trigonous, papery, tri-loculicidal capsule ca. 1 cm long and 1.5 cm wide; seeds numerous, papyraceous, fl attened, shortly obliquely winged, with a dark brown phytomelanous testa. Distribution and ecology. Stenomesson ecuadorense is so far only known from the type locality in southern Ecuador (Fig. 1I) where it grows on what appear to be limestone cliff s above the Río San Luis, just below 1300 m. It was fi rst found by LJ in 2006 and subsequently examined in the fi eld by AM and NO in 2009. As so far known, the species is restricted to these cliff s where it grows in cracks, crevices and narrow shelves on the rock where pockets of humus accumulate. We estimate the population that we observed to consist of several hundred individuals. Th e full extent of occurrence is not yet known.
Etymology. Th e species is named for the nation of Ecuador, to where it so far appears to be endemic.
Notes. Th e genus Stenomesson Herb. (sensu Meerow et al. 2000) includes about 15 spp., and is primarily found in Peru, with only S. aurantiacum Herb. previously reported from Ecuador (Meerow 1990). Th e genus usually occurs in seasonally dry, grassy vegetation or at the margins of cloud forest above 2000 m elevation, but is also found in Peruvian inter-Andean valleys below 2000 m (Meerow and van der Werff 2004), and the loma formations along the coast of Peru. Th e new species, S. ecuadorense, is found below 1300 m elevation in relatively wet habitat.
Stenomesson ecuadorense appears closely related to S. miniatum (Peru, Bolivia; Fig.  2A) and S. campanulatum Meerow (Peru; Fig. 2B) by the orange fl ower color and fusion of the staminal corona to the fl oral tube, but diff ers from them (Table 1) by the unusual limestone habitat and relatively low elevation. S. miniatum has an urceolate corolla, and is always found above 2000 m in elevation to as high as 3500 (unpubl. herbarium data). S. campanulatum has a non-patent limb and long-exserted stamens (Meerow 1985). Th e perianth of S. ecuadorense has fl aring tepals as does S. miniatum, but is long campanulate in morphology. It is only the second species of the genus (sensu Meerow et al. 2000) reported from Ecuador, and so far the only endemic one.
Etymology. Th e species is named in honor of the late Ruth Moore, ardent supporter of conservation eff orts in Ecuador.
Notes. Eucharis subg. Heterocharis was erected by Meerow (1989), even though it appeared paraphyletic in his cladistic analysis of morphological characters. Th e large, fragrant fl owers; numerous ovules per locule, and mature green fruits were considered symplesiomorphic for the genus. Th e subgenus previously included only two fertile species, E. sanderi Baker (1883), endemic to the Chocó region of Colombia, and E. moorei (Baker) Meerow (1987a), found on both the eastern and western declivities of the Ecuadorean Andes. Th e group also contains two apparently sterile taxa, E. × grandifl ora Planch. & Lind. (1853), a putative hybrid of E. moorei and E. sanderi, found in southern Colombia and northern Ecuador (Meerow 1989), most often in cultivation, and E. amazonica Lind. ex Planch. (Meerow and Dehgan 1984). Th e latter, most commonly found in the lower Huallaga Valley of Peru, never sets seed, has a triploid-derived chromosome number (2n = 68), and impaired pollen fertility (Nagalla 1979;Meerow 1987b). Eucharis ruthiana appears most closely related to E. moorei, but is easily separable (Table 2) by the narrower leaves and tepals, the deeply cleft staminal cup with long marginal teeth, the short, nearly fi liform, incurved free fi laments, and the relatively short style.