Isabel Martínez-Solís

Effects of environmental factors on seed germination of Anthyllis barba-jovis L.

Abstract The influence of the main environmental factors on seed germination of Anthyllis barba-jovis L. were analysed. This work is part of a broader investigation aimed at the reintroduction of this species on Mount Conero, Ancona (central Italy), where it is at present extinct. The seeds were collected from the Gargano headland (southern Adriatic coast). Experimental analyses were carried out to determine: (i) dormancy levels of seeds collected in successive years, and also collected from the soil seed bank; (ii) effects of usual pre-treatments for overriding the physical dormancy of the seeds; (iii) optimal temperature range for maximum germination; (iv) effects of fire on seed germination; and (v) effects of NaCl on germination and on early stages of seedling development. Our results confirm that A. barba-jovis seeds have a physical dormancy due to their teguments, which are water-impermeable. This barrier persists in naked seeds that remain in the soil. Regularly water-drenched seeds show a high germinative ability. The optimal seed germination temperature is 20°C, with germination decreasing progressively at lower temperatures, and falling drastically over 20°C. Fire and high temperatures positively affected germination. The seeds were shown to be strongly resistant to salt stress, thus enabling the plants to colonize a habitat suitable for halophytes.

MORPHOLOGICAL AND ANATOMICAL STRUCTURE OF GALLS IN GENISTA FLORIDA L. SUBSP. POLYGALIPHYLLA (BROT.) COUTHINO (LEGUMINOSAE)

ABSTRACT This paper describes the morphology and anatomy of a structure which appears in the floral racemes of Genista florida L. subsp. polygaliphylla (Brot.) Couthino. In this subspecies the floral racemes have a small number of flowers. This structure develops quite frequently in this taxon, which is found in the northwest of the Iberian Peninsula, but never in Genista florida subsp. florida. Its morphology is simple: bottle-shaped, wide at the base and elongated to a narrow peak at the upper extreme. Anatomical examination shows that these structures have a close similarity to flowers. Since they develop by the oviposition of one insect of the Cecidomyiidae family in the floral buds, they can be considered galls. This fact is of great interest in the taxonomy of the group because the number of flowers is a differential character between the two subspecies of G. florida.

La sección Rhamnastrum Rouy (Rhamnus, Rhamnaceae) en el norte de la Península Ibérica

Martinez-Solis, I., Iranzo, J., Corbia, J.T., Estrelles, E. & Ibars, A.M. La seccion Rhamnastrum Rouy (Rhamnas, Rhamnaceae) en el norte de la Peninsula Iberica. Lazaroa 19:9-16 (1998). Se presenta un estudio anatomico y morfologico de los taxones pertenecientes a la seccion Rhamnastrum Rouy presentes en el norte de la Peninsula Iberica. Los datos obtenidos se tratan estadisticamente mediante la utilizacion de tecnicas de clasificacion y se concluye que pueden reconocerse tres especies (Rhamnus alpina L., Rhamnus legionensis Rothm. y Rhamnus pumila Turra).