A Grammatical Dictionary of Botanical Latin

cygneus,-a,-um (adj.A): relating to swans; (a line) curved suddenly downwards like a swan's neck; “the seta of Mosses when curved so as to suggest a swan’s neck” (Jackson); (bryophytes) “curved like a swan’s neck; e.g. setae in many species of Campylopodium and Campylopus” (Magill 1990); see ‘downwards, bent;’

cygneous (Eng.adj.): sigmoid: strongly curved in two directions: one way in the upper part, the other in the lower, like the neck of a swan; in bryophytes, used of the flexure of the seta.

- (moss) theca in pedunculo supra perichaetium exserto atque cygneo reclinata (C. Mueller), the theca bent down on a peduncle [i.e. seta] many times exserted above the perichaetium and also cygneous [i.e. curved suddenly downward].

- [moss] theca minuta ovata in pedunculo cygneo demissa (C. Muell.), theca minute, ovate, nodding on a cygneous [i.e. swan-necked] peduncle [i.e. seta].

Persicaria cygnea Greene (Polygonaceae).