The Island of the Colorblind

Brilliantly colored fungi sprouted in the wet earth – Beata knew them all, which were poisonous, and what remedy to use if poisoned; which were hallucinogenic; which were good to eat. Some of them, Tommy told me, were luminous at night – and this was also true of some of the ferns. Looking down among the ferns, I spotted a low, whisklike plant, Psilotum nudum  – inconspicuous, with stiff leafless stems the diameter of a pencil lead, forking every few inches like a miniature tree, bifurcating its way through the undergrowth. I bent down to examine it, and saw that each tiny fractal branch was capped with a yellow three-lobed sporangium no bigger than a pinhead, containing all the spores. Psilotum grows all over Guam and Rota – on riverbanks, in the savannah, around buildings, and often on trees, as an epiphyte drooping like Spanish moss from their branches – and seeing it in its natural habitat gave me a peculiar thrill. No one notices Psilotum, no one collects it, esteems it, respects it – small, plain, leafless, rootless, it has none of the spectacular features which attract collectors. But for me it is one of the most exciting plants in the world, for its ancestors, the psilophytes of the Silurian, were the first plants to develop a vascular system, to free themselves from the need to live in water. From these pioneers had come the club mosses, the ferns, the now-extinct seed ferns, the cycads, the conifers, and the vast range of flowering plants which subsequently spread all over the earth. But this originator, this dawn-plant, still lives on, humbly, inconspicuously coexisting with the innumerable species it has spawned – had Goethe seen it, he would have called this his Ur-pflanze.[86]

If the cycads conjured up for me the lush forests of the Jurassic, a very different, much older vision rose before me with the Psilotum: the bare rocks of the Silurian – a quarter of a billion years earlier, when the seas teemed with great cephalopods and armored fish and eurypterids and trilobites, but the land, apart from a few mosses and lichens, was still uninhabited and empty.[87] Psilophytes, stiff stemmed as no alga had ever been, were among the first colonizers of the bare land. In the dioramas of ‘The First Life on Land’ I so loved as a child, one could see panting lungfish and amphibious tetrapods emerging from the primordial waters, climbing aboard the now-green margins of the land. Psilophytes, and other early land plants, provided the soil, the moisture, the cover, the pasture, without which no animal could have survived on land.

A little farther on, I was startled to see a large accumulation of empty, broken coconut shells on the ground, but when I looked around, there were no coconut palms to be seen, only cycads and pandanus. Filthy tourists, I thought – must have come in and thrown these husks here; but there were few tourists on Rota. It seemed odd that the Chamorros, who are so respectful of the jungle, would leave a pile of refuse here. ‘What is this?’ I asked Tommy. ‘Who brought all these shells here?’

‘Crabs,’ he said. Seeing my confusion, he elaborated. ‘These large coconut crabs come in. The coconut trees are over there.’ He gestured toward the beach, a few hundred yards away, where we could just see a grove of palm trees. ‘The crabs know they will be disturbed if they eat them by the beach, so they bring them over here to eat.’[88]

One shell had a huge hole, as if it had been bitten in half. ‘This must have been a real big crab to do this,’ Tommy observed, ‘a monster! The crab hunters know when they find coconut shells like this that there are coconut crabs all around, and then we search, and then we eat them  – I would like to catch the crab that did this!

‘Coconut crabs love the cycads, too. So when I come out to gather the cycad fruit, I bring along a bag for crabs too.’ With his machete, Tommy cut through the undergrowth, making a path. ‘This is good for the cycads – it gives them room to grow.’

‘Feel this cone!’ Tommy said, as we came to a large male plant – I was surprised to find it warm to the touch. ‘It is like a furnace,’ said Tommy. ‘Making the pollen gives it heat – you can really feel it as the day cools, in the evening.’ Botanists have known for about a century (and cycad gatherers, of course, for much longer) that the cones may generate heat – sometimes twenty degrees or more above the ambient temperature – as they ready for pollination. The mature cones produce heat for several hours each day by breaking down lipids and starches within the cone scales; it is thought that the heat increases the release of insect-attracting odors, and thus helps in the distribution of pollen. Intrigued by the almost-animal warmth of the cone, I hugged it, impulsively, and almost vanished in a huge cloud of pollen.