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Hollow Moon Planetology: Blue Moon -- Vegetation by Sharon Dornhoff

((Sorry if the biology-speak gets a little thick in this latest post, folks: if you're not interested in botany or you couldn't care less how photosynthesis takes place, just skip on to the last two sections, and read up on which sorts of vegetation are typical of the Hollow Moon. If, OTOH, you're a professional botanist who's outraged that I've got something totally wrong, please pardon my zoologist's misconceptions! :- D))

Lunar Vegetation: Gardening in the dark

Of the four Immortals -- Ka, Ordana, Korotiku, and Seshay-Selene -- who originally made Matera's interior habitable to life, Ordana definitely had the toughest job. Because the Hollow Moon receives only a fraction of the sunlight available to plant life on Mystara, and none at all in the red- to-yellow wavelengths, unmodified plants couldn't be introduced to Matera and expected to survive. Without plants for photosynthesis, there wouldn't be oxygen for animals or other organisms, so merely stocking the HM setting with dark-growing fungi wasn't an option: fungi don't produce oxygen, they USE it! Nor would magically-altering endangered plants to grow without light be an acceptable solution, as this kind of drastic intervention wouldn't be much different from having their original species go extinct, after all. Something had to be done that would adapt plants to extremely low light-levels, without changing them beyond recognition.

One might ask why Ordana didn't just send every endangered plant she came across to the Hollow World, and create all-new species for the inner moon? After all, there's plenty of sunlight there! Unfortunately, it's not that simple: Many plants, contrary to popular impression, NEED periods of darkness, at least for part of their life-cycle. Many flowering plants bloom only at night, and are pollinated by moths or bats; others, particularly in the tropics, rely on bats or nocturnal rodents to distribute their fruits and sow new plants. Desert plants perform gas-exchange, opening their stomata to take in CO2, only at night when they won't desiccate. Far from a paradise for vegetation, the Hollow World's eternal noon is actually a threat to the survival of many species which Ordana -- once a treant, hence a plant and gardener of plants, herself! -- accepts responsibility for. (Besides which, Ordana could sympathise with how "uncomfortable" a plant must feel, to be yanked from Mystara's familiar day/night cycle and left with no pattern by which to time its photosynthetic activity; she'd probably have felt pretty leaf-witheringly miserable, herself, under such circumstances! ;-D)

Fortunately, Ordana's a very sharp lady... er, tree. She's found ways around the twin problems of endless light in the HW, and not nearly enough of it in the HM. In fact, we've already seen one of her solutions: the Hollow World's Floating Continents! Sure, humans may use them to tell time; but IMHO they're much more than just a calendar, put there for the convenience of sentient beings -- they're how Ordana provides brief interludes of shade, be it on a daily, weekly, monthly, or annual basis, for those HW plants which NEED darkness to complete their life cycle! For arctic plants which only set seed if there's a shift from winter dark to summer light, or "short-day" plants like cockleburrs that won't flower unless the photoperiod approximates that of their native habitat's growing season, the shadows of flying continents provide a substitute for nightfall, allowing these plants to survive and reproduce in their original, unmodified state, even in the absence of the day/night cycle their physiology demands.

That's fine for plants that could thrive in the light, so long as there was at least an occasional interval of darkness ... but what about shade- plants? What about plants that depended on nocturnal pollinators, or underbrush-species that wouldn't fit into the existing ecosystems of the Hollow World's jungles? For those endangered plants which couldn't adjust to life under Ixion's eternal sun, more-drastic intervention was called for. (Plus, the Hollow Moon needed some plant life, too!) Ordana had to give plants the ability to live on very little light; and, in order to preserve those plants' original characteristics, she needed to do so in a way that left their physical and genetic structure as unchanged as possible. What she eventually did, was to change HM plants' chloroplasts and photosynthetic pigments, without changing the plants themselves.

Chloroplasts*, pigments, and light-wavelengths

Plant life -- on Earth, Mystara, or any other world -- uses chemical pigments to collect photons of light. Different pigments gather different wavelengths of sunlight; the bright-green chlorophyll a, for example, captures red or blue wavelengths (and reflects green ones back to our eyes). These pigments, and the chemical reactions of photosynthesis they make possible, occur in organelles -- cell "organs" -- called chloroplasts, which all green plants and most varieties of alga share. Unlike most organelles, chloroplasts have their own DNA, distinct from the DNA of the cells they are found in; this is because chloroplasts were once free-living organisms called cyanobacteria, before they evolved into the symbiotic partners of plant cells. The light-trapping pigments of photosynthesis are assembled inside the chloroplasts, and most of the instructions for producing these chemicals are encoded on the DNA of the chloroplast, not the DNA of the whole plant. By modifying its chloroplasts' DNA -- and ONLY the genes of chloroplasts -- Ordana could change which pigments and wavelengths a plant used to photosynthesise, without altering the rest of the plant in any way. The process was even reversible, as she could later replace the modified chloroplasts with normal ones, should she choose to re-introduce the species to Mystara at some later date.

(* - For the non-biologists: Chloroplasts are tiny green sacs found inside plant cells. The chemical pigments which trap light-energy -- green chloryphylls and red-orange carotenoids -- are found inside them. Using photons of light as energy, green leaf-cells assemble CO2 molecules from the air into sugar, on which the plant can nourish itself. This is the process called "photosynthesis"... synthesising sugar, using light as a power-source. DNA is genetic material: the molecular "language" in which instructions for an organism's growth -- how it's shaped, what the different cells do, which chemicals its body makes use of, etc -- are written. Those "How- To-Grow" instructions are the organism's genes.)

The first thing Ordana did, and continues to do, to plants destined for the Hollow Moon, is to change the ratio of pigments their chloroplasts produce. As light in the HM is very dim, she tripled the absolute amount of pigments in each chloroplast, turning even the palest of leaves dark, dark green. As red wavelengths are missing from Materan "sunlight", she reduced the amount of chlorophyll a (which collects mostly red and purple light) in favour of the other two plant-pigments, chlorophyll b (collects oranges and blue-greens) and the carotenoids (collect green, blue, indigo or violet light). The latter sorts of pigments are reddish-orange in colour, and are what give autumn leaves their coloration, once a plant loses its summer chlorophyll; in the Hollow Moon's vegetation, carotenoids and chlorophylls combined give growing leaves a deepest-brown to pitch-black colour, all year round.

The second change which is made to a plant's chloroplasts, before Ordana will transplant it into the Hollow Moon, is the addition of two new pigments to their repertoire: phycobilins and fucoxanthin. In nature, phycobilins are found only in red algae and the cyanobacteria from which chloroplasts descended; fucoxanthin is an unusual carotenoid that occurs in diatoms and brown algae, but not in true members of the Plant Kingdom*. Neither of these is capable of synthesising sugars on its own, but they increase the efficiency of photosynthesis by the other pigments, capturing those wavelengths which the others miss and passing such photons on to a molecule of chlorophyll a. Between them, phycobilins and fucoxanthins make leaves that fall in the Hollow Moon change from dark brown or black, when fresh, to a rich maroon shade almost like the colour of venous blood(!), when they're dried up and dead. That's assuming they're examined under artificial light, so that the reddish tone of phycobilins is visible; under the natural, indigo light of the Firmament, dead leaves still look black.

(* - Algae are too primitive in their reproductive methods and structure to be "true" plants.)

The rest of the process of adapting vegetation to darkness, Ordana didn't have to induce: the plants did that, on their own. Sensing the low light-levels, shrubby plants in the Hollow Moon grow much longer and "floppier" than their ancestors on Mystara had, hugging the ground and spreading out in all directions, like creepers. Leaves grow broader and thinner than they would under full sunlight, and they're much softer so coarse cellulose-fibres won't obstruct the few traces of light which strike them. Stems, runners, thorns and even pigmented flowers harbour photosynthetic activity; not even the feeble light of luminous insects, dropping by at a blossom for pollen, is squandered! Leaflets, leaves, and even whole branches shift their orientation, to follow the "sun" in its slow trek across the Firmament, every month. It's no use for rangers to look for moss on the sides of a tree, to determine which direction is north, in the Hollow Moon: mosses, leaves, boughs and all spread their green surfaces either dawnward, upward, or duskward, because those are the directions from which the best light comes, no matter what the time of year.

Why did Ordana go to all this trouble, instead of just saying "Alacazam!" and giving HM plants the ability to live without light...? Well, first of all, the whole point of the Hollow World/Moon project is to preserve species' and cultures' unique virtues; transforming plants in such a fundamental way would run counter to the purpose for which the Immortals had saved them, in the first place. Second, as a Hierarch of Time, Ordana knew very well that subtle adjustments are the best form of divine intervention, in the long run; her own quest for Immortality would've taught her not to drastically mess with a situation, if there's a simpler way to resolve things. The third reason was that, without Ixion's support as a Full Hierarch, the patron Immortals of the Hollow Moon have to allocate their resources much more sparingly, as they maintain the setting; besides, "throwing magic at it" is how Energy solves problems, not the other Spheres! Fourth, it was a challenge for her to devise a low-magic way of adapting plants to darkness -- kind of like a puzzle, for her to have fun working on. And fifth and last, Ordana's a treant, herself, and just didn't like the notion of plants growing without sunlight: like undead things "living" without food or air or water, it simply gave her the creeps.

The practical outcome of all this, so far as D&D campaigns are concerned, is two-fold. One: lunar plants look WEIRD! Alive, their leaves are black; their bark is black; their needles and thorns and sometimes even their flowers are black! Dead and fallen on the ground, as leaf-litter, they LOOK black under the natural light of the Firmament... but shine a Light-spell or torch on them, and that litter turns a deep, bloody red; only the dry, cracking texture underfoot makes it seem any different from wading through an abattoir. It's creepy, it's morbid, it's unearthly -- at least, it should sure feel that way to Mystarans! -- and it makes it even tougher to spot anything moving in the darkness, for PCs who lack infravision. And, two: with the addition of so many extra chemicals to their chloroplasts, and with their relatively-soft texture and thinness, lunar plants' leaves are actually a good deal more nutritious, pound for pound, than their counterparts on Mystara. Therefore, even though plant life isn't very abundant or verdant in the Hollow Moon, there's still sufficient foliage in lunar ecosystems to support healthy populations of browsing animals, because the individual leaves are much richer and relatively few of them grow too coarse to be digestible.

Lunar plant life

Some kinds of plants are much more typical of the Hollow Moon setting than others, although virtually all of them are extinct, or nearly so, on Mystara. (The major exceptions are those plants which were brought to Matera because an endangered nocturnal animal depended upon them, to survive -- e.g. eucalyptus trees, in the Wallaran dreamlands -- or which are raised agriculturally by Immortal-introduced races.) Below are listed a few categories of plants which have been adapted to darkness and transplanted by Ordana, with great success; also a few types that just didn't handle the transition, so can't be found there.

Some of the successes include:

1) Night-pollinated and night-dispersed flowering plants. As already mentioned, many plants had to be sent to the Hollow Moon, and NOT the Hollow World, because even though they grew in sunlight, the task of carrying their pollen or distributing their seeds was carried out by night- active animals, usually bats or moths. Bat-pollination is common in desert plants such as cacti or agave, as well as in a number of tropical trees; moths pollinate yuccas, evening primroses, sweet honeysuckle, and a variety of other trees and shrubs. "Bat flowers" are typically greenish- white to light purple to creamy in coloration, and grow on larger plants, tree trunks, or the squat stems of cacti; they're either very large, or clumped together in a broad inflorescence, so that they make sturdy landing pads for visiting bats, and most have a strong fruity, musky, or fermented aroma. "Moth flowers" smell sweeter and are a lot smaller than bat flowers, and have trumpet-like shapes and various pastel colours, usually either white or (by artificial light) pink or yellow. Beetle- and fly- pollinated plants also appear in the HM setting, with their shallow, stinky blossoms that draw pollinators with a whiff of dung or carrion-scent. There aren't nearly as many night-dispersed plants (i.e. plants whose fruits are distributed by nocturnal animals) as night-pollinated ones, in the Hollow Moon -- fruits do tend to get spread around by something, even if the ideal disperser isn't on hand -- but several ancient varieties of Mystaran fruit trees, such as the figs that once grew in Old Nithia but couldn't adapt to the drying of the region in 500 BC, have been introduced there. Bat- dispersed fruits tend to be sour and fleshy, with a green or yellow-green rind, and sometimes grow straight out from the side of a tree's trunk, in the subtropical midlands.

2) Mosses and other primitive plants. While the Hollow World is home to giant seed ferns and towering lycopods from the past, it's in the Hollow Moon where the humbler strains of ancient mosses, liverworts, hornworts, horsetails, and other damp-loving, primitive plants can be found in abundance. As all these seedless plants require a lot of moisture to reproduce, and are highly susceptible to desiccation, Ordana didn't take the chance on subjecting them to the continuous glare of the HW sun, and adapted them to darkness instead. It turned out to be a good decision: in the absence of grasses, which can't handle the conditions there, meadows and slopes on the western half of the Nearside became covered with dense carpets of moss, and enormous horsetails sprang up like bamboo-stands in swampy, low-lying regions, taking the place of wetland hardwoods (which also haven't done so well, in the HM). So successful are these plants -- so often overlooked, on Mystara! -- that sphagnum and other peat mosses have turned much of Stygia's lower ground into spongy, acidic peat bogs, by their accumulation and decay.

3) Carnivorous plants. While IRL insect-trapping plants obtain nitrogen, not energy, from their prey, it's a convention of the D&D game that man-eating plants derive actual "food", from their victims. Accepting that assumption, it's a given that many plants in the Hollow Moon will seek other sources of nourishment, than photosynthesis -- some (demi)human, some not -- and will prey upon animal life at, or around, the period of fulldark, when light is scarce or non-existent. Virtually any of the carnivorous plant-monsters described in the OD&D or AD&D rules can be encountered on Matera, apart from large hardwood species such as the killer tree or quickwood, and their aggressiveness will vary over the course of a month, in proportion to the amount of light available. (If there's no light, they're ravenous and will attack anything that moves; if there's lots, they're photosynthesising like mad and can't be bothered to hunt!) In addition to the familiar, man-eating varieties, there are also plenty of smaller relatives of the "monster" plants, which might otherwise go unnoticed by PCs; visitors to the moon might come across a foot-tall Cestian gobbler that eats mouse-sized prey, or a pint-sized archer bush that can shoot bats right out of the air! Note that some of these plant-monsters -- the amber lotus flower, for one -- might be tricky for Mystaran PCs to recognise at first, due to the colour-shifting effects of natural lunar light.

A couple of plant types that just didn't work out too well, in the moon, are:

1) Grasses, including grains. While grasses are some of the most successful plants in the world, they didn't do so hot, when introduced to the western half of Matera's Nearside; the long wait between light-periods did them in there. Grasses can grow okay in the eastern lands, where dawn's direct light strikes quite early after a fulldark, and a little light from Oceanus Procellarum glints off the Firmament to fall on the Foecunditatis- Tranquillitatis region. But the west is just too dark, thanks to the Mare Orientale peninsula and other barriers to strong (for the HM!) illumination; there, mosses take the place of grasses, horsetails supplant reeds along lakeshores, and farmers must make do with vegetables and berries in their fields, instead of grains.

2) Large hardwood trees. Regrettably, though Ordana tried her best, she couldn't get any of the larger species of deciduous tree -- oak*, maple, hickory, walnut, elm, etc. -- to grow well in the Hollow Moon. Conifers, cycads, and non-flowering hardwoods such as ginkgoes grow fine there, as do smaller hardwoods like fruit-trees or aspen, but huge, spreading beeches and mighty banyans are absent. HM druids use holly leaves or pine cones for religious purposes, as no oaks means no "proper" mistletoe; slash pine and larch are the "hard" softwoods of choice, for construction. Tree squirrels are diurnal, as are most nut-cracking birds, so the dearth of nut- bearing trees hasn't adversely affected the all-nocturnal lunar ecosystems.

(* - Ordana's rather miffed about that, having been an oak in her mortal life ... although Seshay-Selene's got no fellow-humpbacks in the HM, and she's not complaining! :-D)

Non-Plant "Vegetation": Hollow Moon fungi, seaweeds, and phytoplankton

Although they're not plants, a few other non-animal organisms ought to be mentioned, as they also play a key part in the Hollow Moon's ecology. HM algae and lichens have all undergone Ordana's "chloroplast treatment", to adapt them to a life of dim, blue light; fungi, being heterotrophs*, don't have any chloroplasts and couldn't care less about how dark it is, so needed no special preparation to survive there.

(* - Heterotroph = something that eats to live, e.g. a fungus or animal.)

The simplest and most primitive "vegetation", of course, is prokaryotic: cyanobacteria (the old "blue-green algae") have been around for over 2200 million years. These, and their non-photosynthetic bacterial relatives, are of course present in the Hollow Moon, respectively as aquatic life and as agents of decomposition. The only reason I'm mentioning them here, is because one type of bacterium -- the chemoautotrophic sulphur- bacteria found in tubeworms near deep-sea hydrothermal vents, which make sugar using energy from sulphide-spewing "black smokers" -- also exists in the hot geothermal caverns of Matera's kopru, and is the primary producer for an entire subterranean ecology of which the kopru are the top predators.

Phytoplankton on Matera consists of the same bewildering variety of algae as that of Earth or Mystara; any attempt to recount what's there is probably more than my readers care to hear ;-). One thing that's odd about Materan seas, however, has a powerful effect on lunar phytoplankton: because of their crystalline bottoms, most lunar seas (except Mare Humorum) receive as much or more light from underneath, during fulldark, as they get from above! In response to this, many types of phytoplankton which are capable of movement -- dinoflagellates, euglenoids, motile green algae and free-floating diatoms, for those in the know -- linger near the surface during the lunar "daylight hours", then let themselves fall to the bottom for fulldark, only to rise again in time for the lunar "dawn". A permanent cloud of algae lies at the bottom of every Materan sea, several inches above the crystalline sea-floor and just out of reach of the slow currents which constantly sweep across it. Were the crystal not so chilly, algae would certainly cover it and block the light completely; as it is, they help the currents to keep the seabed clear of debris, by incorporating the worst of the bottom-muck into their tests. Like lunar plants, Matera's phytoplankton is very dark in colour, appearing black under lunar light and a dull, orangish brown in torchlight.

Larger Materan seaweeds, such as kelp, anchor themselves on submarine "islands" of encrusted sand, especially around the fringes of islands where they can benefit from "underlighting", yet still not set their holdfasts directly on the frigid crystal. Lunar seaweeds inflate their flotation-bladders to hover near the surface during "daylight", then deflate them and sink to the illuminated depths at fulldark. It's therefore possible to sail a ship across clear water, in certain locations on the lunar seas, when the Firmament is dark ... only to return to the same coordinates, and find an impassable sargasso of newly-risen seaweeds there, when it's light! Seaweeds on the moon are black under any light, living or dead.

There's nothing special about Materan fungi: there doesn't have to be. Fungi don't photosynthesise, so growing in the dark is normal for them; indeed, the relative sparseness of true plants gives them more places to grow, in the Hollow Moon. Lunar fungi take an astonishing range of forms. In addition to the usual shelf fungi, puffballs, moulds, stinkhorns, morels, and -- of course! -- mushrooms, there are fungi shaped like cups, crowns, deer-antlers, nets, icky lumps of jelly, birds' nests (with eggs), flowers, miniature trees, trumpets, elephants' ears, horses' tails, elves' ears, and even human faces. Many of them also glow in the dark, for no reason anyone's been able to figure out, and they come in a complete range of colours from red to ultraviolet, and in any shade from pure white to jet black. The various carnivorous and/or poisonous fungi from Gaz10 and Gaz13 are present on the moon, along with other dangerous or magical fungi from the OD&D and AD&D games if you want them; edible species are well-known to Materans, and are actively cultivated by the vesper elves and Cynidiceans, as well as other cultures who've learned farming techniques from them. (Please, PLEASE remember that fungi require food -- i.e. rotting organic matter -- and adequate moisture in order to grow, when you're placing fungal forests in the Hollow Moon. I've seen too many modules where huge fungus-gardens provided sustenance for whole cities of drow or goblinoids, without a drop of water and without anything but each other, to feed upon! :-P)

Lichens are a symbiotic hybrid of fungus and alga, or fungus and cyanobacteria, which grow in harsh environments where there's too little food for a pure heterotroph, yet too little moisture for photosynthetic plants or algae. Bare rock-faces, desolate tundra, or open desert are good enough, for lichen; in the Hollow Moon, they're usually the first thing to sprout when a fresh patch of magma cools down, after a volcanic eruption. So-called "reindeer moss" is actually a lichen, and it's an important source of animal fodder on the Oceanus Procellarum, being one of the few forms of vegetation that will grow on the sand-crust "islands" where cryions keep their herds. Lichens IRL do best if there are long, dry spells alternating with brief, wet ones -- mean temperature doesn't matter much, but the predictability of the wet interludes is important -- and the Storm Cycle ensures that Materan lichens get exactly the conditions they need, so lunar lichens grow much, much faster than those on Mystara or Earth.

Lichens aren't the only symbiotic organisms that photosynthesise, on Matera. Many strains of phytoplankton have actually "partnered up" with varieties of more-mobile zooplankton, to make it easier to rise and sink with the changing direction of light. The most spectacular examples of adaptation to the up/down lighting conditions in the lunar seas are the siliceous "glass" corals ... but they're animals, and will have to wait for the next post! ;-D