Novelties in Campyloneurum ( Polypodiaceae ) from Mesoamerica

Three new species are described and another is recognized in Campyloneurum. Two species occur in Mexico to El Salvador and the others two are present in Nicaragua, Costa Rica and Panama. The new species are Campyloneurum acutum A. Rojas, C. leoniae A. Rojas and C. madrense A. Rojas. The first species differs from C. xalapense by broader rhizome scales, acute to attenuate blade apex, commonly two series of areoles between parallel veins, commonly one sori per areole and hydathodes absent or few evident. Campyloneurum leoniae differs from C. irregulare by more compact and non-pruinose rhizomes, thinner stipes, relatively broader, thinner and more opaque laminae, and distribution at lower elevations. Campyloneurum madrense is different to C. angustifolium because it has narrower and darker rhizome scales with denticulate margin, long scales cells and distributed at lower elevations. Finally, Campylonerum pittieri is here recognized as valid species and it differs from the similar C. amphostenon by longer rhizomes with appressed scales that have a patent, long acuminate apices, relative broader laminae, veins evident and distribution at higher elevations.


Introduction
Campyloneurum C. Presl is a Neotropical genus with about 50 species [1].This genus is recognized by having sterile and fertile monomorphic leaves, single, entire and glabrous blades or with few scales on the rachis, sori in 2 -4 rows between the main lateral veins and they born on the tips of included veinlets [2].
Lellinger mentioned two distributional ranges from Campyloneurum irregulare in Costa Rica, between 800 -1500 m and between 2200 -3300 m [5].Rojas found that really are two entities with different geographic and altitudinal distribution.Since the plants with the northernmost distribution between Costa Rica and Nicaragua present a non-farinosous rhizome, rhizome scales are with basal cells less markedly irregular and distribute to (700-) 1200 -1700 m, while the typical form with pruinose rhizome and basal cells of the rhizome scales markedly irregular is located to (1200-) 1700 -2500 m.Rojas also mentioned that lowland plants need to merit consideration of variety or species [6].
Mickel & Smith made difference between C. angustifolium and C. ensifolium (Willd.)J. Sm., principally referring to rhizome scales, the first with long acuminate apex and with oblong cells, the other with rounded to short acute apex and the cells rounded to squarish [7].
Respect to Campyloneurum xalapense Fée, León mentioned that this taxon has differences in the blade form and variation in rhizome scales between lanceolate to linear, related with populations but not between characters [8].Mickel & Smith mentioned different chromosome number between Oaxaca (=74) and Costa Rica (=148) [7], probably due because they are different taxa.
León defined to Campyloneurum amphostenon (Kunze ex Klotzsch) Fée as plants with long-creeping rhizome with dark brown and ovate scales, they are appressed at base, with patent apex [4] [8].Respect to same species, Rojas found two different entities and separated them in his Table 2,[6], relating entity 1 to the entity proposed by León [4] [8] and entity 2 as a possible hybrid that has short-creeping rhizome with scales 1.5 -3 times longer than wide and brownyellowish, fronds relatively shorter and narrower, veins few evident and distributed at low elevation.
León [8] mentioned 18 species of Campyloneurum from Mesoamerica, but Rojas with the publication of C. gracile and the recognition of C. cooperi and C. irregulare [6], the inclusion of Hyalotrichopteris anetioides (Christ) W.H. Wagner in Campyloneurum [9] and four species that are included in this work; the current number of species for the region arrives to 26.

Table 3 .
Comparison of morphological characteristics among three species of Campyloneurum: C. angustifolium, C. gracile and C. madrense.