Linden Leaf Hibiscus, Two Species in One Shrub

Hibiscus furcellatus

(Hibiscus is an ancient plant name.  Furcellatus means forked, in reference to the forked “antlers” at the flower base.)

Malvaceae

All photos are H. furcellatus, by John Bradford.

One of the showier flowering shrubs around Southeast and South-Central Florida is the Linden Leaf Hibiscus, growing fast, and standing tall with big shocking very-pink blossoms all showy and decorative. The species is almost as ornamental as any garden-variety Hibiscus, and in Hawaii Hibiscus furcellatus is a garden flower, as well as one of the cluster of Hawaiian native Hibiscus species.   It once was widespread in Hawaiian lowlands just as it decorates wet soil Florida.

Linden Leaf Hibiscus has ancient history in Hawaii as a laxative, a nice example of an island culture finding the same use for a species distant mainlanders did, that is, Hibiscus species are sources of laxatives in other cultures.

Note the barricaded flower base.  No sneaking in from the south flank!

Native to Florida, and native to Hawaii?  Isn’t that odd?   Yes, but then again the native Hawaiian flora didn’t flow forth from volcanoes.   Hawaiian botanists suspect Hibiscus furcellatus to have arrived by seed drifting on the ocean, probably from Central America.   How far from, oh say, Panama to Hawaii?  Wonder how long that floating pioneer seed was in the brine.

If a seed floated up onto a Hawaiian beach, it would have grown into one lonely plant.    Being solo, there would have been no mate to pollinate it, nor were its natural pollinators handy, but no worries.   Hibiscus species tend toward a self-pollination mechanism as back-up system.  They make vast seed crops in Florida, littering disturbed mud with countless seedlings.    The flowers “look” like they are fundamentally hummingbird adapted, but hummingbirds are sparse locally, so those profuse seedlings must come from bee-visitation, and/or from that self-pollination capability.

Ant(lers).  Do the barricades protect the bud, or the ant, or the ant food?

 

,The flower owes its name “furcellatus” to forked antlers (modified bracts) surrounding the nectar-rich flower base in this and related species.    The antlers look like they block nectar thieves from side-stepping the front and center proper entrance.   And if the branched barricade is not discouraging enough to flank attacks, the outside base of the flower feeds guardian ants from “extrafloral” nectaries.

Ant headed to nectary on flower bud

The early origins of Hibiscus furcellatus are a mystery to ponder.  Our species seems to be an ancient hybrid of two other species, having two different sets of chromosomes, one full set from each of its parents.  That would be like me having a full set of human chromosomes AND a full set of chimpanzee chromosomes.  One Hibiscus furcellatus chromosome set (called G) probably originated in Africa, as tough as that may be to imagine.  There remain on Earth other species having the G chromosome set uncombined with others.   The second chromosome set (called P) probably originated in the New World where there exist a total of four species having the same ancient GP combo, despite the absence of any known extant species with P alone.   Maybe some bored future genetic engineer will separate the two chromosome sets and re-constitute the two ancestral species.

Seed capsules