Fringe Flora

For a while I did archaeology on Kaua’i, which is at least as fun as you would imagine, despite a psychopathic thug who kept threatening me and one long, rainy, snot-filled stint when I did permanent damage to my wrist wrestling through packed clay. The reward for that was spending days in the presence of Makana (watching the wind place misty lei around the mountain again and again), that and some secret things you cannot hear.

I did more excavation there and then than I had since my initiation in a certain O’ahu valley. A fair volume of dirt moved, for sure, but more importantly a high rate of hitting things. Not cool artifacts and valuable museum pieces, but deep stratification, a cache or two, clear-cut features. And lots of charcoal.

Which is what helped me come up with the idea of a “settlement fringe flora.”

Generations of farmers, cooks, and eaters lay down blankets of soil. Cultivation and fallow, cooking and cleaning, occupation and abandonment: all these things lay down a record. All these things make rubbish and soil, holes and backfill, deposits and discontinuities that archaeologists come along later and read. Charcoal that gets buried in the process, the carbon sequestration incidental to human life, embodies a history of the environment (at least the woody part of it). Locked in charcoal is the cell structure of a plant, and patient experts could be hired for a dollar a minute to decode this. The information gained is especially useful when you use it to choose samples for radiocarbon dating, and start looking at things over time.

By buying a few hours of this service, I was able to find the obvious: that the 20th Century had wreaked havoc. Also an earlier chapter: arrival of Polynesian farmers caused discernible but less drastic changes like disappearance of some endemics and introduction of some useful plants. Both of these are examples of selection, intentional or not, cultural or natural, evolution’s famous cutting edge.

But what was really interesting to me was that in taro fields and villages alike, certain species managed to stick around through centuries of human presence. Akoko, Kukui, Lama, Ulei,...these four tended to show up whenever there was a fire. The first and last of these make perfect sense in terms of their own adaptation--they can colonize disturbed areas, they are abundant and not too long-lived, they flood the landscape, especially when humans are around and not planting exotic weeds.

Kukui? Not native, but also not necessarily the type of aggro plant that invades and takes over. No, it’s one of those plants that accommodates people so well that they help it along. The plant one, and it will provide oil, wood, dyes, glue, compost, medicine, even a reminder of a god. The hardshelled nuts will roll downhill or hide in soil for years, ready to sprout and make more.

Lama? This is the surprise. Diospyros sandwicensis, Hawaiian ebony (paradoxically pale wood and all). Not the fastest grower or reproducer, possessed of spiritual significance, and not what you would necessarily expect to be burnt willy nilly. Yet it shows up in many a fire pit. Partly, this is just a physical peculiarity, the hardwood probably preserves better than many species. But I have recovered it in areas where it would have been wiped out in a generation of uncontrolled harvest, where the only way for it to have been used over the long run would be for people to maintain its presence (conservation or cultivation? I dunno).

These four species, I think, are part of a fringe flora. Plants that occur around human settlements. All had uses in the organic technology of Hawaiians, all provided fuel to warm and cook, all escaped extirpation. All maintained some place in an environment settled and farmed, all occupied a Polynesian landscape in evolutionary stasis.