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 Sicyos (Cucurbitaceae, Sicyeae, Sicyinae) from Mexico and Guatemala

Sicyos lirae is described as a new species from Chiapas, Mexico, and Guatemala. It grows in zones with primary or secondary montane rain forest at elevations between 1400 and 3800 meters. In Guatemala the species is commonly called “güisquil de ratón.” It is similar toSicyos galeottii Cogn., from which it differs in blade consistency, shape of the stigma lobes, and several important ovary and fruit characters.     

A new species of ceratozamia (Zamiaceae) from Chiapas,Mexico

Ceratozamia norstogii sp. nov. from Chiapas, Mexico is described. This species is distinct from all others in the genus in that it has a straight rachis with very narrow leaflets (3–10 mm wide) which are strongly curved and almost round in cross section when dried. It is known only from Chiapas, Mexico and in cultivation.     

A new species of Carex from Chiapas,Mexico

Carex chiapensis, sectionFecundae, from Zontehuitz, municipio de San Cristóbal de Las Casas, Chiapas, is described as new.     

A new species of Sechium sect. Frantzia (Cucurbitaceae, Sicyeae, Sicyinae) from Mexico

Sechium mexicanum is described as a new species ofSechium sect.Frantzia. It differs from the remaining species of the section by several features of the inflorescences and staminate flowers, the obovoid and completely unarmed fruits, and pollen grains with 9–10 narrow, poorly defined colpi. It is endemic to Mexico and the first member of sect.Frantzia to be recorded outside of Central America. It grows at 900–2300 m in mesophilous forests and in oak and pineoak forests in the states of Hidalgo, Puebla, Querétaro, and Veracruz.     

A new species of Thenardia (Apocynaceae,Apocynoideae) from Chiapas,Mexico, with notes on the genus

A new species,Thenardia chiapensis, is described and illustrated. The new species is the first taxon in the genus to have its fruits, two fused follicles, described and illustrated. In addition, observations ofT. floribunda specimens have revealed the existence of a novel character, coiled filaments, previously undescribed for the genus.     

A new species of Zehneria (Cucurbitaceae) from Somalia

The new species Zehneria somalensis , from shady limestone rocks in north-eastem Somalia, is described and illustrated.     

A new fossil species of Phlebotominae sand fly from Miocene amber of Chiapas,Mexico (Diptera: Psychodidae)

The male of Pintomyia (Pifanomyia) bolontikui sp. nov., from the Miocene Mexican amber deposits of Simojovel, Chiapas, is described. This is the second fossil phlebotomine sand fly described from Mexico. Morphological differences between fossil and extant species of American phlebotomine sand flies are discussed.     

A new species of Momordica (Cucurbitaceae) from tropical Africa

Momordica littorea , sp. nov., a dioecious climber with succulent 3-foliolate leaves and conspicuously bracteate flowers from coastal regions of southern Somalia and Kenya, is described and illustrated.     

A new species of Mimosa (Leguminosae) from Coahuila,Mexico

Mimosaunipinnata from the Sierra de San Marcos in the Cuatro Ciénegas Basin of central Coahuila, Mexico, is described. It is unique among mimosas in having oncepinnate leaves.     

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

Malaxis molotensis, a new orchid species from a wet cloud forest of the Sierra Madre del Sur, Guerrero, Mexico is described and illustrated. In habit and floral structure it resembles the widespread M. histionantha but differs in the elliptic labellum with incurved distal margin, and elongate, oblong-falciform pollinaria.     

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.

     

Combinational dormancy in seeds of Sicyos angulatus (Cucurbitaceae,tribe Sicyeae)

Seeds with a water‐impermeable seed coat and a physiologically dormant embryo are classified as having combinational dormancy. Seeds of Sicyos angulatus (burcucumber) have been clearly shown to have a water‐impermeable seed coat (physical dormancy [PY]). The primary aim of the present study was to confirm (or not) that physiological dormancy (PD) is also present in seeds of S. angulatus. The highest germination of scarified fresh (38%) and 3‐month dry‐stored (36%) seeds occurred at 35/20°C. The rate (speed) of germination was faster in scarified dry‐stored seeds than in scarified fresh seeds. Removal of the seed coat, but leaving the membrane surrounding the embryo intact, increased germination of both fresh and dry‐stored seeds to > 85% at 35/20°C. Germination (80–100%) of excised embryos (both seed coat and membrane removed) occurred at 15/6, 25/15 and 35/20°C and reached 95–100% after 4 days of incubation at 25/15 and 35/20°C. Dry storage (after‐ripening) caused an increase in the germination percentage of scarified and of decoated seeds at 25/15°C and in both germination percentage and rate of excised embryos at 15/6°C. Eight weeks of cold stratification resulted in a significant increase in the germination of scarified seeds at 25/15 and 35/20°C and of decoated seeds at 15/6 and 25/15°C. Based on the results of our study and on information reported in the literature, we conclude that seeds of S. angulatus not only have PY, but also non‐deep PD, that is, combinational dormancy (PY + PD).     

A new species of Nemastylis (Iridaceae) from Mexico

A robust, yellow-floweredNemastylis from the state of Colima, Mexico, is described as new.     

A new species of Bidens (Compositae) from Mexico

Bidens longistyla, an annual species with a square stem and yellow rays, known only from the States of Nuevo León and Coahuila, Mexico, is described as new.     

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 Astomiopsis (Ditrichaceae) from Mexico

Astomiopsis saintpierrei Thér. ex Buck is described as new from Nevado de Toluca in Mexico. It is characterized by oblong-lanceolate leaves with recurved margins and a percurrent costa. The capsules are immersed, have a well-developed, deciduous annulus, and are covered with a large, cucullate calyptra. A key to the five known species ofAstomiopsis is given.     

A new species of Psilostrophe (Compositae) from Mexico

Psilostrophe mexicana is described as new and compared with the closely related speciesP. gnaphalodes. Chromosome numbers forP. mexicana are reported asn = 32, a tetraploid number. This new species is the seventh and only polyploid species in the genus.