What is "linnaea borealis"

Linnaea borealis \Lin*n[ae]"a bo`re*a"lis\ (l[i^]n*n[=e]"[.a] b[=o]`r[-e]*[=a]"l[i^]s) n. [NL. Linnaeus Linn[ae]an + L. borealis northern.] (Bot.) The twin flower which grows in cold northern climates.

Twin \Twin\, a. [OE. twin double, AS. getwinne two and two, pl., twins; akin to D. tweeling a twin, G. zwilling, OHG. zwiniling, Icel. tvennr, tvinnr, two and two, twin, and to AS. twi- two. See Twice, Two.]

1. Being one of two born at a birth; as, a twin brother or sister.

2. Being one of a pair much resembling one another; standing the relation of a twin to something else; -- often followed by to or with.
   --Shak.

3. (Bot.) Double; consisting of two similar and corresponding parts.

4. (Crystallog.) Composed of parts united according to some definite law of twinning. See Twin, n., 4.

   Twin boat, or Twin ship (Naut.), a vessel whose deck and upper works rest on two parallel hulls.

   Twin crystal. See Twin, n., 4.

   Twin flower (Bot.), a delicate evergreen plant ( Linn[ae]a borealis) of northern climates, which has pretty, fragrant, pendulous flowers borne in pairs on a slender stalk.

   Twin-screw steamer, a steam vessel propelled by two screws, one on either side of the plane of the keel.