About Thyrsanthella difformis (Walter) Pichon
Thyrsanthella difformis (Walter) Pichon is a deciduous, low-growing woody twining vine that belongs to the dogbane plant family. Its leaves are arranged oppositely along stems, have smooth entire margins, a tapered acuminate tip, and can grow into a wide variety of shapes. Its flowers range in color from white to creamy yellow, lack a corona structure, have corolla lobes that measure 3–4 mm long, and bloom from May through July. Its fruits are reddish, are pod-like follicles 10–25 cm long and 1–2 mm in diameter, and develop from July through September. Variable leaf shape can make this species challenging to identify in some cases, especially when encountering the narrow-leaf form for the first time. Thyrsanthella difformis is frequently confused with trumpet honeysuckle, invasive Japanese honeysuckle, or Carolina jessamine. In the field, you can distinguish T. difformis from these three species by checking for milky sap: only T. difformis exudes this milky sap when stems are broken or the central vein of a leaf is torn. It can also be told apart from the introduced alien confederate jasmine, which was formerly classified in the same genus as T. difformis, by the difference in flowers: the native T. difformis has unassuming pale yellow flowers, while the introduced confederate jasmine produces showy white flowers. One published source reports that all parts of Thyrsanthella difformis are poisonous when ingested.
