Laburnum Laburnum Laburnum, sometimes called golden chain or golden rain, is a genus of two species of small trees in the subfamily Faboideae of the pea family Fabaceae. The species are "Laburnum anagyroides"—common laburnum and "Laburnum alpinum"—alpine laburnum. They are native to the mountains of southern Europe from France to the Balkans. Some botanists include a third species, "Laburnum caramanicum", but this native of southeast Europe and Anatolia is usually treated in a distinct genus "Podocytisus", more closely allied to the "Genisteae" (brooms). The "Laburnum" trees are deciduous. The leaves are trifoliate, somewhat like a clover; the leaflets are typically long
Slice genus Slice genus In mathematics, the slice genus of a smooth knot "K" in "S" (sometimes called its Murasugi genus or 4-ball genus) is the least integer g such that "K" is the boundary of a connected, orientable 2-manifold "S" of genus "g" properly embedded in the 4-ball "D" bounded by "S". More precisely, if "S" is required to be smoothly embedded, then this integer "g" is the "smooth slice genus" of "K" and is often denoted g("K") or g("K"), whereas if "S" is required only to be topologically locally flatly embedded then "g" is the "topologically locally flat slice genus"