Resumen de Apuntes sobre anatomía y morfología de las semillas de cactáceas. I. Desarrollo y estructura

Eugenia M. Flores, E.M. Engleman

• español

  En general, la información referente a la embriología de Cactaceae es fragmentaria y con frecuencia contradictoria. Por esta razón, en el presente estudio se describe el desarrollo y la estructura de los rudimentos seminales y semillas de 18 especies de Cactaceae en un intento de confirmar, modificar o ampliar la información al respecto. Al describir los rudimentos seminales llamaremos lado dorsal, en funículo y rudimento seminal, a aquel lado que alcanza mayor desarrollo al curvarse el rudimento. El lado ventral del funículo, queda entonces próximo al Iado ventral del tegumento externo y al micrópilo.

• English

  The morphology and anatomy of ovules, immature and mature seeds of 18 species of Cactaceae (pereskieae, Opuntieae and Cereae B. and R.) have been studied in an attempt to understand their development and their structure. Characteristics of the nucellus, the micropyle, the funiculus and the funicular covering (Opuntieae) in the ovule, and features of the seed coat, the embryo, the perisperm, the hilum and the hilum cup in the mature seed have been analized.The ovular position is amphitropous in most species. The funicular covering of Opuntieae commonly called "aril or third integument" is a true funicular covering and this structure is different from that of arils. There is a relationship between the degree of thickening in the integuments and the size and form of the hilum and hilum cup. Apparently, the presence of tannins incrusted on the cell wall of seed coat cells increases the hardness of the walls and gives them the brittleness