a. [ Cf. F. involucral. ] Pertaining to, possessing, or like, an involucrum.

{ } a. (Bot.) Having an involucre; involucred. [ 1913 Webster ]

n. [ L. involucrum a covering, wrapper, fr. involvere to wrap up, envelop: cf. F. involucre. See Involve. ] (Bot.) (a) A whorl or set of bracts around a flower, umbel, or head. (b) A continuous marginal covering of sporangia, in certain ferns, as in the common brake, or the cup-shaped processes of the filmy ferns. (c) The peridium or volva of certain fungi. Called also involucrum. [ 1913 Webster ]

a. (Bot.) Having an involucre, as umbels, heads, etc. Martyn. [ 1913 Webster ]

n. (Bot.) An involucel. [ 1913 Webster ]

‖n.; pl. L. Involucra E. Involucrums [ L. See Involucre. ] [ 1913 Webster ]

1. (Bot.) See Involucre. [ 1913 Webster ]

2. (Zool.) A sheath which surrounds the base of the lasso cells in the Siphonophora. [ 1913 Webster ]