The Sunflower (helianthemum annuus) is an example of one of the plants belonging to this division which has seeds yielding oil.
It feeds from August to May on rock rose (helianthemum), eating the withered and even mouldy leaves.
I have seen a similar instance in a less degree in a species of helianthemum.
Cross section of the ovary of Frost weed (helianthemum), with three parietal placent, bearing ovules.
Laid on the petals of the common furze (Ulex europæus), and on leaves of rock-rose (helianthemum chamæcistus).
Thus, certain species of helianthemum are apetalous in Lapland.