Facts:

An endangered butterfly, the Green Hairstreak Butterfly is isolated to three small parts of the city: Hawk Hill Park,Rocky Outcrop Park, and a small portion of the Presidio. Green Hairstreak larvae feed exclusively on the Coastal Buckwheat and conservation projects have focused on creating a corridor of these plants to “bridge” the three populations and prevent inbreeding. There are 50 green hair streaked butterflies left!

Explanation: Thomas just looked randomly and came along this.