Juglans jamaicensis a newly grown shoot. The fruit is a drupe roughly 2 to 3 centimeters long with a black husk and a seed, which is an edible walnut meat, inside. In Puerto Rico there are only ten to fourteen trees of this species remaining. It is also rare in Cuba and Hispaniola. It is threatened by habitat loss. It may never have been common, but specimens were likely lost when forest was cleared for coffee plantations on Puerto Rico, and it was probably harvested for wood. The attractive wood is similar to that of the black walnut ("Juglans nigra"). This tree
Two-sided market that the greater the multihoming costs, the greater is the tendency toward market concentration. Higher multihoming costs reduce user willingness to maintain affiliation with competing networks providing similar services. Attracted by the prospects of large margins, platforms can try to compete to be the winner-take-all in two-sided markets with strong network effects. That means that one platform serves the mature networked market. Examples of the standards battles include VHS vs Betamax, Microsoft vs Netscape and the DVD market. Not all two-sided markets with strong positive network effects are optimially supplied by a single platform. Markets must have high multi-homing costs