Oil secretion and the pollination of Colpias mollis (Scrophulariaceae)

摘要: Colpias mollis is a perennial lithophyte that secretes non-volatile oil as pollinator reward. Its white to yellow flowers bear two narrow pouches lined with glandular oil-secreting trichomes. The pollinating bee, Rediviva albifasciata (Melittidae), collects its forelegs and midlegs by rubbing them against the gland patches within flower. presence of specialised hairs on these legs facilitates oil-collection. strongly congruent geographic distributions C. R. their close morphological fit suggest long association between plant pollinator. Although appears dependent for pollination, not always oil. It can also obtain utilise from annual herb Hemimeris racemosa (Scrophulariaceae). At main study site, fruit set was high (75.7%; N=202 flowers) in dry year when H. rare relatively low (11.4%; N=184 wet common.