Hailing from the hills of Honduras/Eastern Guatamala, Passiflora citrina is a delightful form of passionflower, found growing in moist pinewoods. A beautiful free-flowering plant which may be in bloom 10 months of the year. Pollinated by hummingbirds, if you have one about your person.
The leaves are very distinct, paddle shaped and quite a lot like a blunted Liriodendron tulipifera, though thicker, velvety and textured.
Minimum temperatures 4ºC/40ºF, so one for an all year round cool conservatory – a large one as growth can extend 12-15ft – 3.6m-4.7m, though kept in a pot and trained up slender canes, it may be more manageable and will flower for months on end.
A bit of Botany and Biology…
For a passionflower, the diminutive blooms are relatively simple, while still exhibiting family characteristics.
The structure of Passiflora blooms is unusual, with the ovary and stamens held aloft from the centre of the flower on a long column. It has been suggested that this arrangement evolved to avoid damage from visiting pollinators (usually bees, although this and the large red-flowered species are visited by hummingbirds) that probe for nectar at the base of the petals. Keeping the ovary – all important for seed production – out of harm’s way will make sure that the visiting pollinator contacts the stigmas and stamens on both the way in and the way out. The flowers are protandrous, meaning the anthers shed their pollen first and then, once it has all been removed by pollinators, those three nail-shaped stigmas on top of the ovary move outwards and become receptive, so promoting cross pollination.
There are photographs on the blog A Digital Botanic Garden, noted in the side bar, of this yellow variety and the more common, but more fantastical Passiflora caerulea. Thank you for notes on flower structure too.
This example flowering just inside the automatic doors of the Glasshouse at RHS Wisley. There is an exhibition of the winners of the International Garden Photographer of the Year (IGPOTY) on there at the moment, and a selection of Fuchsias well worth closer inspection, as well as the usual delights.