Clock Vine, Sky Vine

Thunbergia grandiflora Roxb.

(with comments on T. battiscombei)

thune-BERG-ee-ah grand-ah-FLORE-ah

Acanthaceae 

Explanation of name:  Generic name commemorates Swedish botanist Carl Thunberg, 1743-1822, student of Linnaeus; grandiflora means large-flowered.

Natural range:  Tropical Asia, escaped in Florida (WU2)

Recognition: This large, aggressive vine has opposite cordate-hastate leaves and large, bilaterally symmetrical sky blue flowers with a yellow center. ‘Alba’ is a white-flowered cultivar. 

Thunbergia battiscombei Turrill is similar but less common.  Thunbergia battiscombei has rich purplish (vs. blue or white) flowers, is smaller, and is less vigorous.  This is a useful alternative for a sunny situation where a T. grandiflora may be too large and aggressive.  Although a well behaved vine if unpruned, T. battiscombei can be pruned into a shrub.

Landscape uses: A staple of tropical fence and wall landscaping.  A big aggressive vine.  Flowers extremely showy.   May suffer from nutrient deficiencies or from nematodes.