Pollen morphology of browneopsis (Leguminosae: Caesalpinioideae), and its evolutionary significance

Abstract

The pollen of the bat- and moth-pollinated Browneopsis is spheroidal to oblate-spheroidal in shape, 3- or 4-colporate or 3- or 4-porate, with verrucate ornamentation. Three types are recognised: (1) 3-colporate with long, distinct colpi and verrucae interspersed with dense adpressed clavae or fine verrucae; (2) 3- or 4-colporate with short, indistinct colpi and irregularly shaped verrucae interspersed with a fine reticulum; (3) 4-porate with large scattered verrucae interspersed with adpresscd clavae. There is a trend from colporate to porate pollen which is reflected in the petals which range from well-developed to rudimentary. The closely related bird-pollinated genus Brownea has distinctly different pollen which is prolate to prolate-spheroidal in shape, 3-colporate and with striate, striate-reticulate or reticulate ornamentation. The pollen morphology of the two genera is discussed in relation to pollination biology. © 1992, Taylor & Francis Group, LLC.