Friday Fabulous Flower - a Gesneriad

Almost didn't get to a fabulous flower today what with so many things to get ready for next week.  With the days getting longer, the glasshouse collection is looking a bit livelier, and at least one new species will bloom soon, one obtained as a small plantlet.  This particular tropical plant gets over looked because it grows in a shadier, even dim, part of the greenhouse, and it's flowers are not particularly gaudy or bright and showy, and that is a bit strange.  But then again, the pollinator of this species is not altogether obvious, and although hummingbirds have been known to visit the flowers, it just isn't exactly their type of flower except for the orientation.  This isn't the first time TPP has featured a gesneriad, a member of the Gesneriaceae, the African violet family to many people because that's the house plant most people know.  This is Drymonia stenophylla from Costa Rica, and the flowers, just after a rain provided by the mist system, are rather subtle with the pale yellow and pinks.  The corollas are quite waxy, almost artificial in appearance, but otherwise similar to the better know Episcias.

Friday Fabulous Flower - Kohleria

Gesneriaceae is best known for African violets, but many other members are showier and even easier to grow, of course, my F1 grows better African violets, so the Phactor is not the best authority on their cultivation. This neotropical species, probably Kohleria eriantha, grows as a very vigorous, almost constantly flowering, sub-shrub in our glasshouse. The reason people like this genus is obvious; the flowers are fairly large, bright in color, fuzzy, and the corolla has very bold nectar guides. Nectar guides like this usually absorb UV light and the areas between reflect it, so in those wavelengths, they are very bold. This tells you they are not adapted for human eyes. Numerous hybrids exist, but in general they are avoided in our use as real species are prefered for teaching botany. If you wish to learn how flowers work these are a nice example of how a "bisexual" (bisporangiate really) flower uses movement of floral parts and sequential functionality to promote outcrossing. When this flower first opens the two pair of stamens are positioned at the top and front of the corolla tube thus ready to daub pollen on the back of any visitor, which based on the floral size and features, will be a bee. The style is above and below the anthers, out of the way, and the bilobed stigma remains closed. After a day of dispersing pollen the spent anthers fold back, and the style takes their place with an open stigma, thus changing the flower to pollen accepting. It's a good exercise to assign this to students for them to figure out how this flower works.

Friday Fabulous Flower - Episcia

International travel and the recovery rom it has left the Phactor day and date disoriented. Almost let Friday slip away without posting a fabulous flower, not that there haven't been lots of nice flower posts of late, but TGIFFF. Today's flower, Episcia lilacina is a close relative of a couple of well known house plants in the gesner family. It's sort of funny; a plant like this is hard for many people to grow, and this species has not been used as a temperate house plant to my knowledge even though it has a larger flower than the two cultivated species in our greenhouse, but down in Costa Rican rainforests this lovely plant with it's pale lavendar flowers and varigated leaves with purple on their undersides grows upon bare clay banks in the dark understory. The problem with growing such a plant is quite simply the difference in humidity, and the arid winter air in our houses is just too dry for many tropical plants.

Attractive display for dispersers of tropical plant

It's been awhile since blogging about the tropics. Those of us who study flowers are used to seeing diverse displays to attract pollinators. This is also true for fruit displays attracting seed dispersers. Now of course both of these are floral displays, but at different times in the flower's functional life, and most people just aren't used to thinking of fruits as flowers at the time of seed dispersal.

What is truly unusual is to have the same display being used for attracting both pollen and seed dispersers because they are almost always at different times and for different organisms. This a member of the Gesner (African violet) family from Costa Rica, Columnea purpurata, and the leaves are arranged to make a flat array along a stem forming a canopy over its flowers and fruits. So this is photographed from below as this branch extends out over your head (it grows as an epiphytic shrub). Both the flowers' persistent calyx and the subtending bract are bright orange and hairy, and the entire cluster of flowers, at both dispersal stages, produces a single display. At the right hand end of the cluster you can just see a yellow corolla tube and at the left hand end an orange berry is visible (arrows). The reason one display works for both dispersal stages is that birds are the dispersers of both pollen (hummingbirds) and seed (diverse frugivores), and such a large, bright display is needed in the shady understory.