Cytogenetics and embryology of Eupatorium laevigatum (Compositae)

Cytogenetics and embryology of Eupatorium laevigatum (Compositae)

Embryological studies indicate Eupatorium laevigatum to have Antennaria type diplospory with precocious embryony. The embryo sac is of the Polygonum type and the polar nuclei fuse before anthesis (maturation of the stamens). Endosperm development is autonomous and the central cell divides only after the initial stages of embryo formation. It is estimated that about 10% of the florets in anthesi...

Embryology

coloured plates. These are of the very greatest value in assisting one to follow the meaning of the letterpress. This, we think, is particularly the case in the chapter dealing with Meckel's diverticulum. The volume is one that should prove itself of great value to surgeons and physicians and as a book of reference. As would be expected the publishers have done their share of the work in a most...

Wood Anatomy of Vernonieae (Compositae)

Systematics of Isocarpha (Compositae: Eupatorieae)

Isocarpha comprises five species ranging from southern Texas and the Bahamas to northern Peru and northeastern Brazil. The genus belongs in Eupatorieae rather than Heliantheae, but structure of the head of Isocarpha with its elongate, chaffy receptacle is anomalous within Eupatorieae. An hypothesis is presented suggesting the evolutionary derivation of this type of head through formation of flo...

Wood Anatomy of Eupatorieae (Compositae)