[Taxacom] Polygonum cespitosum or P. caespitosum?

[Dilrukshan Wijesinghe]

A quick question: What is the correct spelling of the specific epithet of the so-called Oriental Lady' s Thumb or Cespitose Smartweed: cespitosum or caespitosum? It appears as cespitosum in Gleason & Cronquist's Manual of Vascular Plants of Northeastern United States and Adjacent Canada, 2nd ed. 1991 (11th printing 2009, p. 137) and in the USDA PLANTS Database (http://plants.usda.gov/java/profile?symbol=POCE4) but as caespitosum in several popular recent publications (e.g. Del Tredici, 2010, Wild Urban Plants of the Northeast, p. 260).

Thanks.

Priyantha

D. P. Wijesinghe
dpwijesinghe at yahoo.com