Monarch Amazonvine

Stigmaphyllon emarginatum (Cav.) A. Juss.

stig-ma-FILL-on ee-marge-ah-NAY-tum

Malpighiaceae

Explanation of name: Generic name means “leaf stigma,” in reference to an expanded leafy portion on the stigma. Emarginate means notched.

Natural range: West Indies

Recognition: Heavy woody vine having opposite, often egg-shaped leaves and bright golden round flowers, the five paddle-shaped petals abruptly narrowed at the base. Each flower has three stigmas. The fruits are winged.

Landscape uses: Large, robust vines with golden showers of blossoms. Very showy when in bloom, followed by reddish fruits. Covers chain link fences.

Note: Additional species of Stigmaphyllon are in cultivation, including “S. littorale A. Juss.” [a synonym of  S. bonariense (Hook. & Arnott) C. Anderson, Brittonia 48: 543. 1997 (“1996”). See the reference below where the synonymy is explained.], Orchid-Vine or Butterfly-Vine. It would be easy to confuse the cultivated species. Persons with a serious taxonomic interest should consult: Anderson, C. Monograph of Stigmaphyllon (Malpighiaceae). http://www.ars-grin.gov/cgi-bin/npgs/html/stdlit.pl?Syst Bot M

Syst. Bot. Monogr. 51: frontisp. + 1-313. 1997.

Based on Anderson:

            Stigmaphyllum bonariense has a unique samara (winged fruit) “which is short and broad, broadly triangular to nearly square, dorsal wing encircles the nut. The inflorescences are characteristically borne on long, axillary primary axes. The laminas are mostly [but not always] cordate to broadly ovate to orbicular…”

            Stigmaphyllum emarginatum has the samara with the dorsal wing much longer than wide and the nut ribbed and sometimes with spurs or crests. The inflorescences are umbels or (pseudo)racemes on peduncles 1.3-25 mm long. The laminas are extremely variable.” Anderson notes this species to be distinguished by its unusual posterior styles. All three styles are efoliolate (without a leafy flap), and the erect, stubby, posterior styles are caniculate-complicate and apically truncate.