Native Plants
Over the long evolutionary eons, it was much easier for ancestral plants to speciate into different niches than it was for new plants to get here, so most of the native Hawaiian species evolved here and are endemic to the islands (occurring nowhere else in the world). The ancestors that did arrive found a plants’ paradise, with no large herbivorous mammals to eat their leaves or trample their roots, and in the process of natural selection most new species lost defensive mechanisms. As a consequence, they became quite vulnerable when mammals were later introduced by humans. Hawaiian plants are often rare, unique, and imperiled, which makes them important not only for the interest they hold, but also for their conservation. Native plants have green colored signs.
Polynesian Cultural Heritage Plants (Canoe Plants)
About thirty plants came with the first Polynesian settlers, and were the ones chiefly used, for cordage, clothing, medicine, food, and more. In Hawaiian cosmology these plants are related to people through common ancestry, and through kinolau associations, as well as through the interactions of cultivation and use. Because Hawaiian culture is native to these islands, these are also often called native plants, which is inaccurate in a scientific sense, but reflects the popular understanding that these heritage plants have a greater time depth and a longer interrelationship with Hawaiian landscapes than more recent introductions. Canoe plants are indicated by blue colored signs.
Cosmopolitan Plants
The third group of plants began arriving in the islands with the first ships that came from Europe. This category includes large shade trees, showy ornamental plants, and many plants used frequently in lei-making today. Brown colored signs are the most abundant colored sign on campus, they represent this post-European introduced group of plants.