spathe
noun
ˈspāt͟h 
: a sheathing bract or pair of bracts partly enclosing an inflorescence and especially a spadix on the same axis
the spathe of the calla lily
Example Sentences
Recent Examples on the Web The foliage appears in late fall, grows all winter and in late winter/early spring produces a whitish green spathe bloom. 
Janet Carson, Arkansas Online, 20 Dec. 2021 By Monday morning, the 6-foot-tall flower remained in full, glorious bloom with its blood-red petal spathe slowly darkening to a deep maroon, but its smell was more muted. San Diego Union-Tribune, 1 Nov. 2021 After a monthlong growth cycle, the spathe, or the petal-like sheath around the flower’s spadix (a beige, fleshy spike), began folding back around 3 p.m. Sunday. San Diego Union-Tribune, 1 Nov. 2021 Look for a maroon spathe (basically a leaf that covers a flower) and get close enough to get a whiff of its namesake. Chelsey Lewis, Milwaukee Journal Sentinel, 2 Apr. 2020 The spathe on the corpse flower is striped green and white on the outside and a meaty red within. Ciscoe Morris, The Seattle Times, 31 May 2017
Janet Carson, Arkansas Online, 20 Dec. 2021 By Monday morning, the 6-foot-tall flower remained in full, glorious bloom with its blood-red petal spathe slowly darkening to a deep maroon, but its smell was more muted. San Diego Union-Tribune, 1 Nov. 2021 After a monthlong growth cycle, the spathe, or the petal-like sheath around the flower’s spadix (a beige, fleshy spike), began folding back around 3 p.m. Sunday. San Diego Union-Tribune, 1 Nov. 2021 Look for a maroon spathe (basically a leaf that covers a flower) and get close enough to get a whiff of its namesake. Chelsey Lewis, Milwaukee Journal Sentinel, 2 Apr. 2020 The spathe on the corpse flower is striped green and white on the outside and a meaty red within. Ciscoe Morris, The Seattle Times, 31 May 2017 Word History
Etymology
New Latin spatha, from Latin, broadsword — more at spade
First Known Use
1785, in the meaning defined above