Part 15 (1/2)
Plants like animals require ”food convenient for them,” certain const.i.tuents of the soil, certain characteristics of environment, that they may flourish and fulfil their purpose. This delights in conditions that few tolerate--saline mud, ooze and frequent flooding by the salt sea. Drifting into shallow water the sharp end of the spindly radicle bores into the mud. At once slender but tough roots emerge in radiating grapples, leaves unfold at the other extremity, and the plan of conquest has begun. During the early period of its life there is nothing singular in the growth of the plant In a few months, however, it sends out arching advent.i.tious roots, which on reaching the mud grasp it with strong finger-like rootlets. These arching roots, too, send out from their arches other roots that arch, and the arches of these similarly repeat themselves, and so on, until the tree is underpinned and supported and stayed by an elaborate and complicated system, which while offering no resistance to the sweep of the seas, upholds the tree as no solid trunk or stem could. Then from the plan of arches spring offshoots, in time to become trees as great as the parent. Aerial roots start a downward career from the overhanging branches, anchoring themselves in the mud. Some young seedling drops and the pointed end sticks deep in the mud, and grows forthwith, to possess arching and aerial roots of its own, and to make confusion worse confounded. The ident.i.ty of the original founder of the grove is lost in the bewildering labyrinth of its own arches, offshoots, and aerial roots, and of independent trees to which it has given the mystery of life. One floating radicle with its pent-up energy, having after weeks of drifting and swaying this way and that to the slightest current and ripple, grapples Mother Earth and makes a law to the ocean. Among the interlacing roots seaweed, sodden driftwood and leaves lodge, sand collects, and as the level of the floor of the ocean is raised the sea retires, contributing by the flotsam and jetsam of each spring-tide to its own inevitable conquest.
Not to one plant alone is the victory to be ascribed. As in the army there are various and distinct branches of service, so in this ancient and incessant strife between land and water, the vegetable invaders are cla.s.sified and have their appointed place and duties. Neither are all the const.i.tuents of a mangrove swamp mangroves. In the first rank will be found the hardiest and most highly specialised--RHIZOPHORA MURCRONATA, next, BRUGUIERA GYMNORRHIZA (a plant of slightly more lowly growth but prolific of arching and aerial roots); BRUGUIERA RHEEDI (red or orange mangrove.) Some of the roots of the latter spread over the surface and have vertical kinks. The roots and the accessories act as natural groynes, causing the waves to swirl and to precipitate mud and sand. BRUGUIERA PARVIFLORA and CERIOPS CANDOLLEANA a.s.sist in the general scheme, the former depending upon abutments for security instead of advent.i.tious roots. Its radicles resemble pipe-stems, or as they lie stranded on the beach, slightly curved and with the brown tapering calyx tube attached, green snakes with pointed beads.
Surprising features are possessed by the tree known as SONNERATIA ALBA.
The roots send up a mult.i.tude of offshoots, resembling woodeny radishes, some being forked, growing wrong end up. All the base of each tree is set about with a confusion of points--a wonderful and perfect design for the arrest and retention of debris and mud. Some of these obtrusive roots are much developed, measuring 6 feet in height and about 4 in. diameter.
No less remarkable is the help that the white mangrove (AVICENNA OFFICINALIS) affords in the conquest with its system of strainers.
Though different in many respects from the SONNERATIA, it too has erect, obtrusive, respiratory shoots from the roots, slender in comparison, resembling asparagus shoots or rake tines (called by some cobbler's pegs) and which strain the sea, retaining light rubbish and a.s.sisting to hold and consolidate it all. Each of the plants mentioned is equipped in a more or less efficient manner for the special purpose of taking part in the reclamation of land. In some the roots descend from the branches to the mud where roots ought to grow; in others, roots ascend from the mud to the upper air, where, ordinarily, roots have no sort of business.
Each possesses varying and distinct features well designed to aid and abet the general purpose.
Other species of marine plants have their duty too. That which is known as the river mangrove (AEGICERAS MAJUS)--which does not confine itself to rivers--comes to sweeten the noisome exhalation of the mud, and with its profuse white, orange-scented flowers, to invite the cheerful presence of bees and b.u.t.terflies. The looking-gla.s.s tree (HERITIERA LITTORALIS), with its large, oval, glossy, silver-backed leaves and boat-shaped fruit, stands with the river mangrove along the margin farthest from the sea, not as a rearguard, but to perform the function of making the locality the more acceptable to the presence of plants which luxuriate in sweetness and solid earth. Another denizen of the partially reclaimed area of the mangrove swamp is the ”milky mangrove,” or river poison tree, alias ”blind-your-eyes” (EXCAECARIA AGALLOCHA). In India the sap of this tree is called tiger's milk. It issues from the slightest incision of the bark, and is so volatile that no one, however careful, can obtain even a small quant.i.ty without being affected by it. There is an acrid, burning sensation in the throat, inflamed eyes and headache, while a single drop falling into the eyes will, it is believed, cause loss of sight. Yet a good caoutchouc may be prepared from it, and it is applied with good effect to ulcerate sores, and by the blacks of Queensland and New South Wales for the relief of certain ulcerous and chronic diseases; while in Fiji the patient is fumigated with the smoke of the burning wood. Several of the plants produce more or less valuable woods. BRUGUIERA RHEEDI frequently grows slender shafts, favoured by blacks for harpoon handles on account of their weight and toughness. White mangrove provides a light, white tough wood eminently adapted for the knees of boats. The seeds resemble broad beans, and after long immersion in the sea will germinate lying naked and uncovered on the scorching sand, stretching out rootlets in every direction in search of suitable food, and expanding their leathery primary leaves--even growing to the extent of several inches--while yet owing no attachment to the soil. If it were not capable of surviving and flouris.h.i.+ng under conditions fatal to most plants it could not contribute its quota to the formation of humus favourable to the progress of the advancing hosts of tropical vegetation.
A weird and stealthy process is this invasion of the ocean, which leads to the alteration and amendment of the surface of the globe. Here, may be watched the very growth of land--land creeping silently, irresistibly upon the sea, yet with a movement which may be calculated and registered with exact.i.tude. Having fulfilled its purpose, the mangrove suffers the fate of the primitive and aboriginal. Tyrannous trees of over-topping growth, which at first hesitatingly accepted its hospitality, crowd and shove, compelling the hardy and courageous plant to further efforts to win dominion from the ocean. So the pioneer advances, ever reclaiming extended areas as the usurping jungle presses on its rear.
Nor must it be imagined that mangrove swamps are unproductive. Fish traverse the intricacies of the arching roots, edible crabs burrow holes in the mud, and in them await your coming, and more often than not baffle your ingenuity to extricate them. Among other stalked-eyed crustaceans is that with one red, s.h.i.+elding claw, absurdly large, and which scuttles among the roots, making a defiant clicking noise--the fiddle or soldier crab (GELASIMUS VOCANS). Oysters seal themselves to the roots, and various sorts of sh.e.l.l-fish gather together--two or three varieties appear to browse upon the leaves and bark of the mangroves; some excavate galleries in the living trunks. The insidious cobra does not wear any calcareous covering beyond the frail tiny bivalves which guard the head--a scandalously small proportion of its naked length--but lines its tunnels with the materials whence sh.e.l.l is made, smooth and white as porcelain. How this delicate creature with less of substance than an oyster--a mere worm of semi-transparent, stiff slime--bores in hard wood along and across the grain, housing itself as it proceeds, and never by any chance breaking in upon its neighbours, though the whole of the trunk of the tree be honeycombed, savours of another wonder. Authorities consider the bivalve sh.e.l.l too delicate and frail to be employed in the capacity of a drill, and one investigator has come to the conclusion that the rough fleshy parts of the animal, probably the foot or mantle, acting as a rasp, forms the true boring instrument. Thus, the skill of a worm in excavating tunnels in wood puzzles scientists; and the cobra is certainly among the least conspicuous of the denizens of a mangrove swamp, and perhaps far from the most wonderful.
The most remarkable if not the strangest denizens of the spot are two species of the big-eyed walking and climbing fish (PERIOPHTHALMUS KOELREUTERI and P. AUSTRALIS) which ascend the roots of the mangrove by the use of ventral and pectoral fins, jump and skip on the mud and over the surface of the water and into their burrows with rabbit-like alertness. They delight, too, in watery recesses under stones and hollows in sodden wood. Inquisitive and most observant they might be likened to Lilliputian seals, as they cling, a row of them, to a partially submerged root, and peer at you, ready to whisk away at the least sign of interference. They climb along the arching roots, the better to reconnoitre your movements and to outwit attempts at capture.
Their eyes--in life, reflecting gems--are so placed that they command a complete radius, and if you think to sneak upon them they dive from their vantage points and skip with hasty flips and flops to another arching root, which they ascend, and resume their observation. It must not be a.s.sumed that the climbing fish--which seems to be more at home on the surface of the water than below--climbs up among the branches. A foot or so is about the limit of its upper wanderings.
Then, too, in what is generally regarded as a noisome, dismal, mangrove swamp, birds of cheerful and pleasing character congregate. Several honey-eaters, the little blue turtle dove, the barred-shouldered dove, the tranquil dove, the nutmeg pigeon, the little bittern, the grey sandpiper, the sordid kingfisher, the spotless egret, the blue heron, the ibis--all and others frequent such places, and in their season, b.u.t.terflies come and go. In most of its aspects a mangrove swamp is not only the scene of one of Natures most vigorous and determined processes, but to those who look aright, a theatre of many wonders, a museum teeming with objects of interest, a natural aviary of gladsome birds.
THE UMBRELLA-TREE
Having paid, in pa.s.sing, respects to the most gorgeous tree of the island, it would be sheer gracelessness to withhold a tribute to one of the commonest, though ever novel and remarkable--the umbrella-tree. Less conspicuous in its blooming than the flame-tree, it flourishes everywhere--on the beaches with its roots awash at high tide; on the rearguard of the mangroves, leaning on the white-flowered CALOPHYLLUMS; on the steep hill-sides; on the borders of the jungle, and gripping scorched rocks with naked roots.
While the flame-tree--few and confined to the beaches--flashes into bloom--an improvident blaze of colour, without a single atoning green leaf--the umbrella-tree charms for several months with a combination of graceful foliage and a unique corollary of singular flowers.
From the centre of whorls of shapely glossy leaves radiate simple racemes, 2 feet long, as thickly set with studs of dense heads of red flowers as Aaron's rod with its magical buds. Crowned with several crowns of varying numbers of rays, rarely as few as four, frequently seven and nine and occasionally as many as twelve, each tree is a distillery of nectar of crystal purity and inviting flavour. On every ray there may be eighty red studs, each composed of twelve compact flowers, and every flower drips limpid sweetness. For months this unexcised distillation never ceases. For all the birds and dainty b.u.t.terflies and sober bees there is free abundance, and every puff of wind scatters the surplusage with spendthrift profusion. Sparkling in the sunbeams, dazzling white, red, orange, green, violet, the swelling drops tremble from the red studs and fall in fragrant splashes as the wanton wind brushes past or eager birds hastily alight on the swaying rays. A rare baptism to stand beneath the tree for the cool sweet spray to fall upon the upturned face, a baptism as pure as it is unceremonious.
Red-collared lorikeets revel in the nectar, hustling the noisy honey-eaters and the querulous sun-birds. The radiant blue b.u.t.terfly sips and is gone, or if it be his intent to pause, tightly folds his wings on the instant of settling, and is transformed from a piece of living jewellery to a brown mottled leaf caught edgeways among the red flowers.
The green and gold b.u.t.terflies are for ever fluttering and quivering.
The complaining lorikeets peevishly nudge them off with red, nectar-dripping bills, the honey-eaters disperse them with inconsiderate wing sweeps; but the b.u.t.terflies are not to be denied their share.
After a moment's airy flight they return to the feast, quivering with eagerness. And so the weeks pa.s.s, the patient tree generating food far beyond the daily needs of all who choose to take.
By a very moderate computation--such an orderly plan of bloom lends itself to simple statistics--the average production of a fairly crowned tree is over a gallon of nectar per day. Hundreds of trees so crowned brighten all parts of the island with their red rays. And where the nectar is, there will the sun-birds be gathered together--a sweeter notion, truly, than carcases and eagles.
And this nectar, clear as dew-drops, sweet with an aftertaste of some scented spice--a fragile pungency--was ever liqueur so purely compounded?
Drawn from untainted soil; filtered and purified; pa.s.sed from one delicate process to another, warmed during the day, cooled by night airs, chastened by breezes which have all the virtue of whole Pacific breadths; sublimated by the sun--all to what end, to be proffered to birds and b.u.t.terflies in ruddy goblets full to the brim.
THE GENUINE UPAS-TREE
Powerful as nutmeg pigeons are on the wing, some suffer lingering deaths in consequence of a singular characteristic of one of the trees of the jungle. Tall and graceful, with luxuriant glossy leaves, there is nothing uncanny about the tree. In style and appearance it is the very ant.i.thesis of ”the upas-tree,” upon which legendary lore cast unmerited responsibility. Yet in certain respects it would be vain to enter upon its defence. It is no myth. There is no exaggeration in the statement that the character of the Queensland tree is actually murderous, and that it counts its victims by the thousand every season. Of the great host it destroys, all save a few may be very small and very feeble, and from the human standpoint some of its death-dealing is perfectly justifiable if not laudable. Not often, locally, is a bird destroyed, but the fact that occasionally one has the ill-luck to fall foul of it and to perish miserably in consequence, places the tree in the catalogue of the remarkable. Neither spike nor poison is used nor any sensational means of destruction but nevertheless the tree is sure and implacable in its methods.
The seed-vessels of the Queensland Upas-tree, ”Ahm-moo” of the blacks (PISONIA BRUNONIANA), which are produced on spreading leafless panicles, exude a remarkably viscid substance, approaching bird-lime in consistency and evil effect. Sad is the fate of any bird which, blundering in its flight, happens to strike against any of the many traps which the tree in unconscious malignity hangs out on every side.
In such event the seed clings to the feathers, the wings become fixed to the sides, the hapless bird falls to the ground, and as it struggles heedlessly gathers more of the seeds, to which leaves and twigs adhere, until by aggregation it is enclosed in a ma.s.s of vegetable debris as firmly as a mummy in its cloths. Small birds as well as l.u.s.ty pigeons, spiders and all manner of insects; flies, bees, beetles, moths and mosquitoes, as well as the seeds of other trees are ensnared. Spiders are frequently seen sharing the fate of the flies, fast to seeds in the humiliating posture in which Br'er Fox found Br'er Rabbit on the occasion of the interview with the Tar Baby.
Insectivorous plants am common enough in Australia; but the ”Ahm-moo,”
tree does not appear to make use of the carcases of its victims, though it kills on an exceptionally extensive scale.