RESUMENEn el edificio que ocupa el Museo Nacional de las Culturas (MNC), del centro histó-rico de la ciudad de México, se llevaron a cabo excavaciones arqueológicas de las que se derivó esta investigación que tuvo como objetivo recuperar los restos arquebotánicos contenidos en los depósitos sedimentológicos de dichas excavaciones, con la finalidad de establecer las condiciones paleoecológicas de la región y el posible aprovechamiento de plantas. Se analizaron 50 muestras de sedimento que cronológicamente corresponden a finales de la época prehispánica y a la época colonial (siglos XVI a XIX). Los restos vegetales recuperados fueron: semillas y fragmentos de madera, que representaron a 36 géneros y una familia, de los cuales se pudo inferir el aprovechamiento de algunas plantas principalmente con fines alimenticio, medicinal, ceremonial y constructivo, así como algunas otras que aportan información de la vegetación de la región.Palabras clave: macrorrestos botánicos, sedimentos, semillas, maderas, excavaciones arqueológicas. ABSTRACTArcheological excavations were carried out in the building that houses the National Museum of Cultures (Museo Nacional de las Culturas, MNC), which is located in the historical center of Mexico City. The present research derives from these archeological works, whose objective was the recovery of archaeobotanical remains contained in the sediment deposits of such excavations with the purpose of establishing the paleoecological conditions of the region and the possible use of plants. Fifty sediment samples, which corresponded chronologically to the end of the prehispa-

In La Purísima region, Comondú, Baja California

No abstract

The morphological characteristics of pollen grains of Linum species in Mexico have not previously been evaluated in quantitative terms. This study reports statistical values of pollen characteristics – polar axis, equatorial axis, shape, polar area, exine thickness, sexine thickness, nexine thickness, and height and diameter of ornamental pollen elements – of 11 of the 13 endemic species accepted to date and for which material was available: L. cruciata, L. flagellare, L. lasiocarpum, L. longipes, L. mexicanum, L. modestum, L. orizabae, L. pringlei, L. rzedowskii, L. scabrellum, and L. tenellum. The detailed light and scanning electron microscopy study revealed that the pollen is prolate-spheroidal to subprolate, tricolpate and with semitectate exine sculptured with bacula, clavae, gemmae or spines whose height and diameter follow a homogeneous, intermediate, or heterogeneous pattern. The principal component analysis found that five characters, namely the height of the ornamental elements, sexine thickness, exine thickness, diameter of ornamental elements, and nexine thickness, explained the highest percentage of the variance between species. The cluster and discriminant analyses classified some of the species into three groups and differentiated three of them according to their morphology. The difficulty in distinguishing some species through a conventional approach was solved conveniently using palynological traits since the ornamentation pattern of pollen grains was unique and because grains of various species were statistically different, thus representing a tool for identifying Linum species.