STUDIES IN THE CAPPARIDACEAE. XI: CLEOME AFROSPINA, A TROPICAL AFRICAN ENDEMIC WITH NEOTROPICAL AFFINITIES

Abstract

The Tropical West African‐Congolese spiny Cleome previously referred to the neotropical “C. spinosa” is the indigenous, distinct, here newly described C. afrospina, most closely related to the southern South American C. trachycarpa of the otherwise endemic neotropical Section Tarenaya. Early collections (from 1816) and widespread distribution in wet forests and riversides also indicate it to be indigenous and not adventive. Related also is the widespread Brazilian‐Argentinian C. hassleriana Chod. (“C. spinosa” auct. non Jacq.; “C. pungens” auct. non Willd.?), the commonly cultivated “Spider Flower,” once recently collected in the Congo (cultivated?). As the only indigenous spiny Old World Cleome, C. afrospina is a remarkable neotropical element in the African flora. Historical explanations for such disjunctions (continental drift, land bridges) are rejected. Avian long‐distance dispersal is indicated by semi‐aquatic successional habitats of high ecological receptivity, generally annual habit, other highly disjunct vicariads, and self‐compatibility within the group. Similar disjunctions occur in the distribution patterns of many aquatic birds (e.g., whistling ducks—Dendrocygna) and of various tropical plants of ecologically receptive “open” habitats.