XVI International Botanical Congess

The inaperturate pollen of the aperigonate Aroideae has a thick, spongy endexine, which is mostly covered by a polysaccharidic stratum (Weber et al. Int J Pl Sci 160/2, 1999). Pollen of the perigoniate Aroideae (sensu Mayo et al., 1997: Zamioculcas, Gonatopus and Stylochaeton) deviates from that of the aperigonate in important exine and aperture characters (thick nonapertural ektexine and thick apertural endexine in the zonosulcate Z. and G., thin, unstratified ektexine in the inaperturate St.). The palynological characters underline the present tribal alignement of Z./G., and of St., but support even the placement of Z. and G. in a new subfamily with St. still remaining in the Aroideae. The presence or absence of an aperture, of the polysaccharidic stratum or of the spongy endexine appears connected with the aroid floral biology.