Dave Grant, Sandy Hook, NJ

Sandy Hook's Sea Beans
by DAVE GRANT

I once presented a peculiar beach find to my biology advisor in college, Dr. Garner, a zoologist who I assumed knew everything there was to know - at least he had given his students ample reason to think that was the case. It looked to me like a seed, with a seam on its perimeter and a scar where it might have been attached to a stem. After scrutinizing it for a few moments and conferring with his office mate, Vern Churchill - the department botanist, he said, "I give up ... animal, vegetable or mineral?," presumably thinking I was trying to stump him.

Oftentimes the most enigmatic finds on the beach are simply everyday things that are out of place at the shoreline. My "find" had gray fur and black stripes - certainly animal-like features and not unlike a sea mouse, our most peculiar polychaete worm - but it also had a woody feel to it and in my naivete I guessed correctly that it must be a form of plant. Warily we opened it and found it was a seed case, solving part of the mystery and boosting my confidence as a budding biology student. However, it wasn't until years later when I first ate a mango in Florida that it finally dawned on me what it was that had washed up so long ago and how it had arrived there. Being a good beachcomber, I had stuffed it away in a drawer, and remarkably, was able to find it and confirm it was a mango seed.

I often find myself murmuring,"Animal, vegetable or mineral?" when I'm beachcombing, and invariably after I've researched it a bit, the most mysterious object of the day ends up being a seed or fragment of some plant. Since most woody things float, at least for short periods, it's only logical that if they are washed into some water system that they should end up eventually stranding on the beach. Mango seeds remain buoyant for as long as three months, long enough to be carried by the Gulf Stream from the Florida Keys and Bahamas, where it grows, to Sandy Hook.

Plant materials wash up on our shores incidentally or as part of their life cycles. The incidental finds include seeds, nuts and pits from land plants of the flood plains and shorelines and from fruit that animals deposit and humans dispose of in the water. Walnuts, hickory nuts, acorns and samaras from maple trees are often found on beaches located near the river mouths where they washed out. Peach and cherry pits are also common, even on secluded beaches, and are in a sense another pollutant that people heap on the shore.

None of these local seeds or nuts appear to be tolerant enough of the saltwater to have much chance of sprouting after they wash up. However, certain other seeds and nuts, especially tropical ones, are adapted to survive over a year in the sea and still remain viable - a remarkable feat for creatures that in their growth stages are quite sensitive to the desiccating effects of salt.

They are able to do this because most are surrounded by an impervious husk and contain air sacs for flotation. The true " sea beans " are from the tropics and drift north on the Gulf Stream. Although most types rarely make it onto beaches north of Cape Hatteras on this side of the Atlantic, many species have been found in Great Britain and elsewhere in Europe. Here they have been called such things as confinement stones, worm stones, and kidney fat, reflecting the widespread belief that they had curative values. Some were also considered to bring good luck and were fashioned into snuff boxes, teething rings, and even amulets to ward off the Evil Eye. It is said that Christopher Columbus was inspired to search for undiscovered lands to the west by these mysterious gifts from the sea. In fact, the best known of all the drift seeds and fruits (or disseminules) the sea heart (Entada), a seed from a West Indies vine, is called "favas de Colom" - the Columbus-bean, in the Azores.

As with anything found at the beach, drift seeds are interesting, fun to collect, and allow us to speculate like early mariners about currents that wash distant shores. Progeny of those plants that grow at the tenuous limits of the terrestrial environment represent the lunatic fringe of the plant world, ever attempting to expand their ranges away from the safety of the tropics.

A large variety of plant disseminules reach Sandy Hook by drifting from the tropics in the Gulf Stream or down stream from our fresh water rivers and neighboring beaches; being carried in the guts of animals, mostly birds; and through human activates - mostly littering.

Drifting or aquavectant disseminules from the tropics found on our beaches over the years include coconuts, true sea beans, sea hearts, and mangos. The large number of Latin American immigrants around New York City, bodegas catering to their tastes, and the availability of a variety of tropical fruits in area supermarkets, may account for the increase in mango pits at the beach in the last few years. Whole coconuts are hard to miss when they wash up, and we do get them fairly frequently this far north, but fragments like the hacked-off end of the edible inner nut are often puzzling to beachcombers. The word coco is sometimes attributed to the Portuguese, meaning "monkey face." With artistic license it's possible to imagine eyes and a mouth in the dark holes at the end of the nut.

Sea beans and sea hearts are also great oceanic travellers from the tropics and may be more common here than we think. Because they are so buoyant, they tend to be stranded at the highest storm tide drift lines and settle just where they are designed to - high on the drier parts of the beach away from the salt water (and beachcombers).

It is too cold for these tropical and subtropical plants to grow at our latitude, but worth a try at potting them up to sprout them as indoor plants if you find one on the beach. This would certainly be fortuitous for a seed that has survived a thousand mile voyage from the south. However, seeds of local freshwater plants that drift downstream to the sea are not as lucky because they cannot survive or sprout in salt water.

The water-nut, possibly the most puzzling freshwater plant that regularly strands here, is actually from a wetlands plant of European origins. Called a swimming water-nut, Jesuit's water-nut, or Sanghara-nut; it is an edible Old World emigrant. Like many exotic plants it has become well established in North America - probably with coaxing from humans - but not by drifting here. The water-nut (Trapa natans), grows in the freshwater portion of the Hudson River and elsewhere in the East, and thrives in ponds and slow-moving streams. It's a weird and durable trinket from the Jersey Shore that regularly embarrasses "knowledgeable" beachcombers who mistake it for a shark or skate egg case, which it resembles in color and texture.

What's in a name? Recently, it was listed as an invasive species in the Northeast, and ponds must be drained and sterilized to completely remove it. This seemed to be of particular concern to wildlife managers only, at least until I dubbed them "Devil's Heads." Now they seem to have become a prized find by young beachcombers.

Other plant seeds that flow downriver to us are cast off by trees that grow close to the water. The most common are "buttonballs" from sycamores, those magnificent trees of swamps and city streets. The ripe ball is a soft, chestnut- colored mass of hairy seeds that is about an inch in diameter. Countless children toss them around schoolyards, but rarely recognize them on the beach. Sweet gum trees, another freshwater wetlands species of bottom lands and riversides, also drop seed "balls" that find their way to the ocean. These are about the size of the sycamore's buttonballs, but have a honeycombed appearance after a good pounding in the surf.

(Note: The Devil's head is a whimsical name we coined for the water nut - Trapa natans. Dave Grant)

Acorns and hickory nuts are easy to identify once you realize they are not from a sea creature, but from trees that commonly hang over river banks. Walnuts, on the other hand, produce a large, dark corrugated nut that, whole or broken, can cause confusion when you find it anyplace else but under a tree. Often they are split open, revealing an owl-like face to further befuddle beachcombers.

Winged seeds from several tree species end up at the beach in great quantities, especially in the summer and fall. Maple and ailanthus samaras get a boost from the wind and oftentimes end up in rivers, where they drift down to the shore. Both trees are well established on barrier beaches even though they seem to be out of flying range for the seeds. Perhaps their seeds are tolerant of a short dip in salt water. Tulip trees also add flotsam and their "cones" which look a bit like miniature dried pineapples, are made up of scores of tightly packed winged seeds. Both the cones and the seeds are common on the beach. Stripped of the seeds, the cone's stem is about the size and shape of a candle from a birthday cake.

True pine cones are common on the beach too. Equally abundant are the spiney cones of the native pitch pine, which grows on some barrier islands, and Japanese black and Scotch pines - ornamentals that are planted frequently at the shore because they can tolerate the salt spray.

Birds bring "avivectant" seeds to the barrier beaches as they digest the fruit in their guts. In fact most of the plants on Sandy Hook are fruit-bearing and birds distribute their seeds. Robins and cedar waxwings, fruit-eaters in the winter, don't all fly south during the colder months. Many head for the coast and sometimes they are the most abundant winter land bird here. As a result, it is not unusual to find pits of cherries, beach plums, holly, shadbush, and cedar at the beach. Tree swallows rely on bayberries when the insects are gone, allowing them to dally along the coast during the fall migration. Some even overwinter in the mid-Atlantic. By December the shrubs are stripped and the beaches here are littered with the spent seeds that thousands of swallows have passed through their digestive tracts. These often accumulate at the storm tide mark with the seeds of other common beach plants like sea rocket, beach grass and cocklebur, all temperate, salt-tolerant plants that, like their rugged tropical cousins, have seeds that can drift and survive. In fact, sea rocket is so durable, it is said to be the first higher plant that colonized the volcanic island of Surtsey in Iceland.

Finally, this brings us to materials that humans are responsible for. Unfortunately this is not a new phenomenon, since we've tossed our trash into the water since Colonial times, and even the most conscientious of us dispose of our banana peels and peach pits in the sand or overboard. But it may not always be detrimental to the beach. There's speculation among some botanists that prickly pear cactus, an inland plant with fruit that is not utilized heavily by birds, got to some of our offshore islands with the help of native Americans who canoed out to them.

Other human trash includes the obvious, from peanuts, pistachios, and the pits of peaches, plums, apricots, and nectarines that are tossed from boats or left on beaches, to insidious and potentially harmful things like plastic. The little plastic packing peanuts, although not digestible, are eaten by a variety of sea creatures, especially birds, that mistake them for prey organisms.

Animal, vegetable or mineral ... trash or treasure, all of it is interesting to collect; reminding us that the ocean is always full of surprises - most of which end up on the beach.


Visit the official SEA BEAN website for more information by Dave Grant

SOURCES FOR IDENTIFICATION:
C.R. Gunn & J.V. Dennis (1976) World Guide to Tropical Drift Seeds and Fruits. Quadrangle/The New York Times Book Co.
H.B. Guppy (1917) Plants, Seeds and Currents in the West Indies and the Azores. Williams and Norgate, London.
J.P. Scurlock (1987) Native Trees & Shrubs of the Florida Keys. Laurel Press, Pittsburgh

Something to think about:

Return to Field Notes or to Dave's Page