The pollination ecology of Aloe ferox Mill.

The breeding system and pollination ecology of Aloe ferox Mill. were investigated. The relationship between plant height, raceme number, raceme length and percentage fruit success was determined for 93 plants. There was a significant positive relationship between plant height and raceme number but the percentage fruit success did not increase with an increase in plant height, number of racemes and mean and total raceme length. A description of post-anthesis flower development is given. Optimal stigma receptivity occurs 8 to 24 h after anthesis and is synchronized with maximum nectar concentration and volume. The flower morphology of this species suggests a bird- pollinated syndrome. This study shows, however, that African honey bees may also play a role in its pollination. Bees visit the anthers as soon as they are exerted beyond the floral tube and, because the stigmas are at least partially receptive at this early post-anthesis stage, fertilization can be affected. This species is self-incompatible and selection pressures have probably been to minimize the number of flowers open on an inflorescence at any one time. Die voortplantingswyse en bestuiwingsbiologie van Aloe ferox Mill. is ondersoek. Die verhouding tussen planthoogte, aantal trosse, troslengte en persentasie vrugvorming is vir 93 plante bepaal. Daar was ’n betekenisvolle positiewe korrelasie tussen planthoogte en aantal trosse, maar die persentasie vrugvorming het nie vermeerder met ’n toename in planthoogte, die aantal trosse en die gemiddelde en totale troslengte nie. ’n Beskrywing van blomontwikkeling na antese word gegee. Optimale stempelontvanklikheid kom van 8 tot 24 uur na antese voor en is met die maksimum nektarkonsentrasie en -volume gesinchroniseer. Die blommorfologie van hierdie spesie skep die indruk van voëlbestuiwing. Hierdie ondersoek het egter aangetoon dat Afrikaanse heuningbye ook ’n rol in bestuiwing mag speel. Bye besoek die blomme sodra die helmknoppe by die blombuis uitgestoot word en aangesien die stempels ten minste gedeeltelik ontvanklik op hierdie vroeë na-antese stadium is, kan bestuiwing beïnvloed word. Hierdie spesie is self-onverenigbaar en seleksiedruk het waarskynlik gelei tot ’n vermindering van die aantal oop blomme op ’n bloeiwyse op enige stadium.