Source : Webster's Revised Unabridged Dictionary (1913)

Stalkless \Stalk"less\, a.
   Having no stalk.

Source : WordNet®

stalkless
     adj : attached directly by the base; not having an intervening
           stalk; "sessile flowers"; "the shell of a sessile
           barnacle is attached directly to a substrate" [syn: {sessile}]
           [ant: {pedunculate}]