Those who can grow Mexican lime, Citrus aurantifolia, get to brag to their friends who can not, even if they are only a few miles away in slightly cooler spots. It really is marginal here. If it gets too cool in winter, it can defoliate. Frost can damage or kill the stems. Because it stays smaller than other citrus, Mexican lime happens to do well in large pots that can be moved to shelter for winter.
Mature trees can get taller than six feet, but not much higher than first floor eaves. The limber stems have small but sharp thorns. The two inch long evergreen leaves are glossy and nicely aromatic. The small white flowers are actually less fragrant. The round one or two inch wide fruits ripen from rich green to pale greenish yellow. The peel is very thin and tough, which is ideal for squeezing the juice from the very juicy and aromatic, but potentially seedy, greenish yellow pulp within.