Laburnum in "L. anagyroides" and long in "L. alpinum". They have yellow pea-flowers in pendulous leafless racemes long in spring, which makes them very popular garden trees. In "L. anagyroides", the racemes are long, with densely packed flowers; in "L. alpinum" the racemes are long, but with the flowers sparsely along the raceme. The fruit develops as a pod and is extremely poisonous. The yellow flowers are responsible for the old poetic name 'golden chain tree' (also spelled golden chaintree or goldenchain tree). All parts of the plant are poisonous, although mortality is very rare. Symptoms of laburnum poisoning may include
Spanning tree and "routing loops", many routing protocols designed for such networks—including the Spanning Tree Protocol, Open Shortest Path First, Link-state routing protocol, Augmented tree-based routing, etc.—require each router to remember a spanning tree. A special kind of spanning tree, the Xuong tree, is used in topological graph theory to find graph embeddings with maximum genus. A Xuong tree is a spanning tree such that, in the remaining graph, the number of connected components with an odd number of edges is as small as possible. A Xuong tree and an associated maximum-genus embedding can be found in polynomial time. A tree is