Premise: Carex tricephala is a species in the genus "Carex", family Cyperaceae. It is one of only about seven species in "Carex" sect. "Scabrellae". Members of this section have leaf-like bracts, and small spicate inflorescences. "Carex tricephala" is native to Southeast Asia, reported from Cambodia, Indonesia, Laos, Myanmar, Thailand, Vietnam and the Chinese province of Yunnan.
Hypothesis: The "Scabrellae" species are native to Southeast Asia.