Three new species of Ocotea (Lauraceae) from southern Mexico

Three new species ofOcotea (O. disjuncta, O. iridescens, andO. rovirosae) from southern Mexico are described and illustrated.Ocotea disjuncta is related to theO. effusa group, whileO. iridescens seems to be related to theO. heydeana group. The relationships ofO. rovirosae are not clear.      

Three new species of ferns (Woodsiaceae and Polypodiaceae) from Mexico

Three new species of ferns are described from Mexico:Athyrium tripinnatum, Cystopteris millefolia, andPolypodium praetermissum.     

Ten new species of Tibouchina (Melastomataceae) from Mexico

Ten new species of Tibouchina (T. almedae, T. congestiflora, T. connata, T. hintonii, T. macvaughii, T. nanifolia, T. patens, T. roseotincta, T. sinaloensis, andT. thulia) are described from western Mexico. Distinguishing characteristics, phenology, distribution, and phylogenetic relationships are discussed. Illustrations of all these new species are provided.     

Three new Pteridophytes from Mexico

Two new species of ferns and a hybrid horsetail are described from Mexico:Diplazium wendtii, Polypodium microgrammoides, andEquisetum × haukeanum.     

A new species of Tzeltalia (Solanaceae) from Mexico

A new species of Tzeltalia (Solanaceae) from Chiapas, Mexico is described and illustrated: Tzeltalia esenbeckii. A key and a table, distinguishing the members of the genus, are included.     

A new species of Malaxis (Orchidaceae) from Morelos, Mexico

A new species from the Mexican state of Morelos, Malaxis lyonnetii, is described and illustrated. It is similar to M. lepanthiflora but is distinguished by its much smaller flowers, distally uncinate basal lip lobes, and entire, rounded apical lip lobe.

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Resumen  Se describe e ilustra a Malaxis lyonnetii, una nueva especie del estado mexicano de Morelos. Esta especie es similar a M. lepanthiflora, de la que se distingue por las flores mucho menores, los lóbulos basales del labelo distalmente uncinados y el lóbulo apical del labelo entero y redondeado.

     

A new species in the Elaphoglossum petiolatum complex (Elaphoglossaceae) from Mexico

Elaphoglossum trichomidiatum is described from northeastern Mexico. The new species is a member of theE. petiolatum comples, which is widespread in tropical America, Africa, Southeast Asia, and the Pacific Islands. It is unique in the complex and in sectionLepidoglossa in bearing trichomidia on the abaxial blade surface.     

Thirteen new species and two new combinations of Stevia (Asteraceae: Eupatorieae) from Mexico

Thirteen new species of the genusStevia are described and illustrated from Mexico:S. chilapensis, S. coahuilensis, S. crassifolia, S. ecatepecana, S. filodecaballoana, S. mascotensis, S. mexicana, S. oaxacana, S. oligophylla, S. potosina, S. rotundifolia, S. scabrelloides, andS. viejoana. In addition, two varieties,Stevia aschenborniana Sch. Bip. ex Klotzsch var.occidentalis Grashoff andS. palmeri A. Gray var.constricta Grashoff are herein redefined as being distinct species,S. occidentalis andS. constricta stat. nov.Stevia mexicana resemblesStevia trifida Lagasca but differs in the habit.     

A new species of Sicyos L. (Cucurbitaceae) from Oaxaca, Mexico

Sicyos mcvaughii, a new species from Oaxaca, is described and illustrated. It is similar to Sicyos sertuliferus Cogn., and grows in secondary tropical deciduous forest, between 20 and 630 meters.     

A new species of Macrothrix (Anomopoda: Macrothricidae) from Central Mexico

Macrothrix mexicanus sp. nov. is described from central México, a transition zone between the nearctic and neotropics. All localities where it was found are over 1800 meters above sea level. It shows many resemblances with M. laticornis, M. camjatae and M. rosea but is characterized by a persistent dorsal tooth on the valve keel, a spinous papilla on the basipodite of the antenna, the second thoracic limb with a long conical sensillum between scraper 1 and the gnathobase, the endopod of trunk limb IV having two setae; the postabdomen with the dorsal margin bilobed, and the distal segment of the seta natatoria which is unusually long.Abbreviations used on figures EN Endopodite - EP Epipodite - EX Exopodite - IDL Inner distal lobe - ODL Outer distal lobe - GT Gnatobase - E1 Endite 1 - E2 Endite 2 - E3 Endite 3     

Stenocereus zopilotensis Arreola-Nava and Terrazas (Cactaceae), a new species from Mexico

Stenocereus zopilotensis Arreola-Nava and Terrazas, a new species from the Zopilote Canyon, municipality of Zumpango del Rio in the center of the state of Guerrero (Mexico), is described and illustrated. This new species is compared toStenocereus quevedonis J. G. Ortega,S. fricii Sánchez-Mej., andS. pruinosus (Otto) Buxb. based on morphological similarity. Moreover, the new species grows sympatrically withS. pruinosus.     

A new species of Ponthieva (Orchidaceae, Cranichidinae) from Veracruz, Mexico

Ponthieva rinconii, a new orchid species from the foothills of the Sierra Madre Oriental in Veracruz, Mexico, is described and illustrated. It is similar in overall appearance to the wide-ranging upland speciesP. schaffneri, but differs from it in habitat preferences (tropical semi-evergreen forest at 650 m elevation), presence of a loose raceme, and three-lobed labellum with a basal cavity.     

An arsenic-tolerant new species of Eleocharis (Cyperaceae) from Chihuahua, Mexico

A new aquatic, arsenic-tolerant species ofEleocharis (Cyperaceae) endemic to Chihuahua, Mexico, is described and illustrated. It belongs toEleocharis sect.Eleogenus seriesMaculosae. A key for the species ofEleocharis sect.Eleogenus from Mexico is included.

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Resumen  Sc describe e ilustra una nueva especie deEleocharis (Cyperaceae) acuática, tolerante a altas concentraciones de arsénico, y endémica de Chihuahua, México. Forma parte de la secciónEleogenus serieMaculosae. Se incluye una clave para las especies deEleocharis sect.Eleogenus de México.

     

A new species of Castilleja (Orobanchaceae) from central Hidalgo, Mexico

Castilleja hidalgensis is described from several collections from xeric limestone sites in central Hidalgo, Mexico. The new species belongs to a small complex of poorly known and uncommon species within sect.Euchroma, sharing important characteristics withC. macrostigma, the first-described taxon in this assemblage. The new species appears to be rare and highly restricted both geographically and ecologically. A key to the species of theC. macrostigma group is provided.     

Symplocos pachycarpa (Symplocaceae), a new species from southern Mexico

Symplocos pachycarpa is described as new, and an illustration is provided. This species grows in cloud forests and oak-pine forests of Oaxaca and Guerrero, Mexico, and is most similar toS. citrea. A key is provided to distinguishS. pachycarpa from related Mexican species.     

Agave rzedowskiana, a new species in subgenus Littaea (Agavaceae) from western Mexico

Agave rzedowskiana is described and illustrated from the states of Sinaloa and Jalisco, Mexico. This species is a member of subgenusLittaea (Tagliabue) Baker “groupStriatae” of Baker. It is compared withA. petrophila García-Mend. & E. Martínez andA. dasylirioides Jacobi & Bouché.

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Resumen  Se describe e ilustraAgave rzedowskiana de los estados de Sinaloa y Jalisco, México. La especie pertenece al subgéneroLittaea (Tagliabue) Baker “Grupo Striatae” de Baker. Se le compara conA. petrophila García-Mend. & E. Martínez yA. dasylirioides Jacobi & Bouché.