Cucurbita pepo F
for competition purposes, the following distinctions are made between marrows and zucchini (syn. courgette): A marrow is grown on a vining plant, a zucchini on a bush type plant without vines. A marrow generally has rough skin while a zucchini generally has smooth skin. A marrow is generally quite uniform in thickness while a zucchini tends to taper out towards the blossom end.
a. The vine must be trimmed within 2.5 centimetres (1 inch) of the stem.
b. Marrows may be green with green or yellow striping or completely yellowish-white. No orange colouring is accepted.