Tickseeds, Coreopsis

Coreopsis leavenworthii, and close relatives

(Coreopsis comes from Greek for bedbug, some species with bedbugish fruits.   Dr. M. C. Leavenworth botanized in and near Florida.)

Asteraceae, the Aster Family

Today Jon and I worked on something we never work on…landscape species.   Long story with no good natives photo ops. So in honor of garden species, here’s one horticulturists and wild plant enthusiasts both enjoy,  as well as the State of Florida, making Coreopsis species the state wildflowers.    There are over a dozen Tickseeds native in Florida, with two or three commonly encountered in our usual haunts.

Coreopsis gladiata, by John Bradford, above and below.

Species depend on interpretation.  Coreopsis tinctoria beautifies most of North America and varies all over the map. The best interpretation of today’s C. leavenworthii, not my idea, is perhaps as a localized fringe element of that behemoth species. They can interbreed.

We can argue pointlessly about species status, but no sane person of taste and breeding would dare question the beauty of these little gems

C. leavenworthii…after the fruits fall away.

As with all members of the Aster Family, the “flower” is actually multitude, the big yellow “petals” being individual ray flowers.  The dark center hosts a crowd of tiny dark purple disc flowers with orange stigmas, looking like the Clemson school colors.

An Aster Family trait Coreopsis disc flowers display is the sexuality shifting from male to female.   Stigmas rising from the lower reaches of the floral tube push yellow pollen to the surface of the flower head, starting it off male.  As those orange stigmas continue to rise they surpass the pollen, making the flower functionally female.

Watch it…just a few seconds CLICK

The male phase, yellow pollen on the surface of the head.

Female phase.  Pollen mostly gone, and the orange stigmas protruding.

Flip over the flower head.  On the underside there’s a star of what look like sepals, but the points are the tips of specialized leaves (bracts).

As the head transforms from flowers into a cluster of micro-fruits, those bract tips curl up to form a cup protecting the seedlike fruits.   The fruit bowl looks at first glance like a spherical bud.

This “bud” is made of the bract tips seen in the photo just above, now in the fruiting phase.  They curl up together to form a cup around the little fruits.

The fruits give the name tickseed.   They’re paper-flat, and have two tiny horns it seems to help it cling to passing creatures.   Around the perimeter is a narrow wing mayb for fluttering if hte horns don’t snag transport.

Fruit cup opened to show winged bedbug fruit, and some flowers in female phase at top right.

Sleep tight.