flora – Page 10

Tay Meadows Tidbit – Pinesap

Since we’re no longer at Kingsford Lake, I’ve had to discontinue the installment title “Today at Kingsford”. I haven’t been sure what to replace it with. I’d settled on the name “Tay Meadows” for our new location, which is, as the name implies, primarily meadow, and is located in Tay Valley Township, not far from the Tay River. “Today at Tay Meadows” sounded a little awkward, though, and when posting these things previously it wasn’t always today that the observation was made. So I went with “Tay Meadows Tidbit” to represent this recurring series of short-length posts. This will be the first one from the new home.

When I posted about Indian Pipe a couple weeks ago, I mentioned that they had a sister species, Pinesap, Monotropa hypopitys. At the time, I hadn’t ever seen Pinesap, although I’d encountered Indian Pipe on rare occasion before. Well, what should I come across not a few days after making that post, but Pinesap! And not just anywhere, either. This patch is growing beside the driveway, at the edge of the pine forest that the previous owners planted there several decades ago. I happened to notice the plants one afternoon when I took Raven for a walk to the forest down the road. I guess ordinarily, when I’m just driving by, I don’t pay that much attention to the edges of the driveway.

Many of the plants are still young and not fully grown yet; even the tall ones aren’t completely unfurled. However, you can still see that each stem bears many flowers, one of the key characteristics that separates this species from Indian Pipe. Its habitat is another, as the Indian Pipe is associated strictly with deciduous tree species, while Pinesap, as the name implies, is primarily dependent on conifers.

The third feature, of course, is the colour. Indian Pipe is almost always white; the rare individual may be red or pinkish. Pinesap, on the other hand, has two forms. Those that flower early in the summer, such as the ones in these photos, are yellow, while plants that bloom later in the fall are usually red.

For more on the ecology of these two species, visit the original Indian Pipe post.

The plant that eats meat

More than pitcher plants, my favourite bog/fen plant has to be the sundew. I could see them every time I visit a bog and still exclaim, “Oh look! A sundew!” My hiking companions would probably grow tired of hearing that from me. I’m not sure what it is about them that captivates me so – perhaps it’s a combination of their unusual ecology and their delicate appearance.

Whatever the reason, when I walked down to the water’s edge a few weeks ago to look for the pitcher plants, I was also on the lookout for sundews. From the shore, however, I didn’t spot any. That didn’t surprise me too much – they’re small plants, and it would be easy enough to overlook them. Indeed, it was only as I was finishing taking photos of the pitcher plant from the canoe that I happened to spot immediately behind it a sundew, not six inches away, and I hadn’t even noticed it. Then I spotted another. And a third. And then the raft of peat that I’d thought was covered in reddish moss resolved into a whole mass of sundews. As did the red cover on the floating logs. They were everywhere. How had I missed them?

Of course, I took lots of photos once I spotted them, but I found them harder to get good images of than the pitcher plants, because their many spindly arms and delicate features were hard to focus on.

There are seven species of sundew native to North America. Of these, three occur in Ontario. I believe this one is Spatulate-leaved Sundew, Drosera intermedia. The leaves of this species are more oblong in shape, while a similar species, Round-leaved Sundew, Drosera rotundifolia, are, unsurprisingly, round. The third species, Linear-leaved Sundew, Drosera linearis, has long, narrow leaves. Spatulate-leaved Sundew has a very wide range, growing through eastern North America, northern South America, and much of Europe.

Each leaf has many thin tentacles that are tipped in a glassy bead of moisture. These beads resemble dewdrops, and give the group their common name (sundew) and generic name (Drosera, from the greek “drosos”, meaning “dewdrops”). However, while dewdrops are simply water, the beads on a sundew are a more sticky substance produced by the plant. The tip of each stalk has a gland that secretes a sweet mucus that forms the glittery beads of dew. This mucus contains enzymes that are used to trap and subsequently break down prey that are attracted to the sweet secretions. The broad part of each leaf also contains glands that help absorb the nutrients released by the enzymes in the mucus.

Like the open pad of a Venus Flytrap that “snaps” shut when prey lands on it, the tentacles on each sundew leaf have the ability to curve toward potential prey when the “sensors” of a tentacle are triggered. In some species this response can be relatively quick, with the fastest being D. capensis of South Africa, which can completely enclose its prey in 30 minutes. This poor damselfly had the misfortune of landing on the sundew, and is now halfway through becoming the sundew’s lunch. You can see how the leaves and tentacles of the sundew have completely wrapped around the damsel’s legs, and have bent around to further entangle the head. It’s to the plant’s advantage to bring as many tentacles (and their digestive glands) into contact with the prey as possible, since it makes digestion easier and faster.

I’ve called it the plant that eats meat, rather than the pitcher plant which I said drinks meat, because the sundew absorbs its meal without the benefit of the liquidy brew that the pitcher plant disolves its prey in.

Most of the sundews had flower stalks up, but very few were actually blooming. Dan was kind enough to hold the boat in place as we were leaving the site so that I could snap this photo when I happened to spot one with an open flower. As with the pitcher plant, the flowers are generally held on long stalks, well above the carnivorous part of the plant, to increase visibility and keep pollinators away from the danger zone. Each flower may only last a short while, and have the ability to self-pollinate if they don’t receive pollen from another flower. Interestingly, they are able to move to follow the path of the sun over the course of the day. Although they look plain white to us, perhaps there is a UV-reflective pattern on the petals that is best illuminated (to the eyes of insects) when in full sunlight.

The plant that drinks meat

One of the features of Rock Ridge that really appealed to me from our first visit was the small bog that sat just offshore in Rock Lake. Bogs are intriguing habitats to me, perhaps because their unique conditions make them such a rare habitat type, full of interesting and different species found nowhere else in the region. Perhaps also part of it is that they are often very difficult to poke around in, unless one happens to visit a conservation area or such where they’ve built a boardwalk through it. The surface looks deceptively solid, but the thick bed of spongy peat and sphagnum moss is ill-suited for supporting 100-odd pounds of human pressure placed on a very small amount of surface area. Really, without a boardwalk, the only easy way to visit a bog is by canoe or kayak, and even then, you’re mostly limited to circling the perimeter.

The access to Rock Ridge is by canoe, but to reach the actual site by water would involve portaging the boat across a short rapids. This ends up being more work than it’s worth, and by the time you’ve unpacked the boat, carried it around, packed it up again, and then paddled over to the shore by the site, you could have reached the same spot by foot and just have docked the canoe back at the rapids, which is what we’ve been doing. This means we don’t pass the bog by water, as I’d hoped, so I hadn’t had a chance to explore more closely.

A couple of visits ago, however, during a slow period one morning, I clambered down the rocks to the water’s edge and scanned the edge of the bog with my binoculars. I was delighted to spot a couple of pitcher plants growing among the vegetation. Their red flowers projected above the grasses and sedges and caught my eye, but naturally I hadn’t thought to bring my telephoto lens down with me, and the wide-angle just didn’t have the reach for much of a photo. Last visit I took my telephoto down to try for a better photo, and while I got some passable shots, I was only so-so about them. We were in the middle of the move and internet downtime, so I didn’t have a chance to post them in Monday Miscellany.

It turned out to be just as well, as our most recent visit was incredibly slow for birds, and Dan made the suggestion that he could hold the fort for an hour or so if I wanted to walk back and portage the boat over so I could putter around the bog a bit (he also asked me to get photos and GPS coordinates for a phoebe nest that will likely appear over at his blog, Frontenac Birds, perhaps his ulterior motive for letting me skip out for a couple of rounds). It didn’t take much to convince me. Good thing the canoe doesn’t weigh too much.

The peat had built up under the water surface enough that I had some difficulty getting close enough to most of the bog for decent shots, but there was one spot where I had good access and I could pull up right next to the pitcher plant. That one plant got the works as a result.

The pitcher plants we have here are Sarracenia purpurea. Because it’s the only species of pitcher plant to occur in Canada – the only one in the northeastern states, too – it’s often just called “pitcher plant”, but there are between 8 and 11 species (depending on who you ask) of Sarracenia in North America. The full common name for this one is Purple Pitcher Plant (a nice bit of alliteration there), taken from the species name purpurea, which means purple. The rest of the species are all restricted to the warmer climate of southeastern US.

Some of the leaves are indeed purplish, but many are green with blood-red veins. The leaves are modified to form enclosed tubes, the feature that gives pitcher plants their names. Each is topped with a broad “hood”, well-developed in some species although somewhat reduced in the Purple, which functions both to keep out rain (which would collect and flood the tube, allowing insects to escape) as well as to guide unwitting insects to the trap. The leaves all grow from a fleshy rhizome, and plants can be propagated simply by dividing the root.

Although some photosynthesis does take place to provide the plant with sugars, nearly all of its nutrients have to come from the prey it captures. The habitats that pitcher plants usually inhabit tend to be very acidic and nutrient-poor, with nutrients either leached away from the substrate the plant grows on by moving water, or the strong acidity of the environment severely hampering their uptake by the plant. Clearly the need for additional nutrients was the driving force behind the evolution of this special adaptation, though there is some debate about the process by which it happened. One theory suggests that the early ancestors of today’s pitcher plants simply had curled leaves, and eventually, through evolutionary time, the edges fused to become the tubes we see now.

I checked a number of the pitchers to see if any had prey. A few had small gnats or other unidentifiable insects, but inside one was this unlucky firefly, still alive. Pitcher plants use multiple cues to draw potential prey in. The first is visual, the combination of colour and shape. They also produce a nectar just under the inside lip of the tube, to tempt insects to lean in. And thirdly, they give off a distinct scent, although I didn’t try sniffing them.

The inner wall of the tube is slippery, and while many visitors come and go without incident, an insect that leans in too far to get the nectar will slip into the cup. At least one species, S. flava, actually produces a compound in its nectar that acts as a narcotic to insects, affecting their balance. In the case of the Purple Pitcher Plant, the tube is filled with a watery liquid, but not all pitcher plants have that. The inner surface of the tube is lined with downward-facing hairs that make it extremely difficult for the insect to climb back out, and some species have grooves in their walls that further increase the difficulty. Eventually, the bug drowns.

The lower half of the tube is lined with glands that secrete digestive enzymes that start work on breaking down the prey. When a leaf tube is young it will primarily use these enzymes for digestion. As it gets older, into its second year, however, bacteria and tiny organisms in the water increasingly become more important in that function. Some pitchers are also home to particular species of mosquito (Wyeomyia smithii) and midge (Metriocnemus knabi) larvae that are unaffected by the digestive enzymes. These larvae do the job of breaking down the larger prey items, and the pitcher absorbs the nutrients from their droppings. In return, the larvae get protection and an oxygen-rich environment (the oxygen being released into the liquid as a result of the plant’s photosynthesis).

The flowers of the plant are just as unique as their method of securing nutrients. They nod from a tall stem, which hopefully keeps potential pollinators above any risk of falling in. The flowers themselves are formed of two cup-shaped parts – the red petals that curve down from above, and the green style that curves up from below. The style is part of the female reproductive organ, which in the average plant is long and narrow with the receptive stigma, what the pollen stick to, on one end and the ovary at the other. In the case of pitcher plants, the style is five-parted but fused together into one large surface, like an inverted umbrella. Where each of the umbrella’s “spokes” would reach the edge and form a point there is a stigma. The anthers, which produce the pollen, hang inside the central green tube. The umbrella-shaped style helps to catch pollen that may fall from these.

Although it’s not demonstrated well in this photo, ordinarily the five red petals hang down in the gaps between the five pointed stigmas, preventing bees and other pollinators from entering there. The bees have to go in over the stigma, and in doing so brush on any pollen they may have picked up at the last flower they visited. They tromp through the fallen pollen on the umbrella surface, and up into the centre tube. When they turn around to leave, they can push the red petal out of the way and leave by the gap between the stigmas, easier than climbing over the stigma again. This way the plant avoids having the bees fertilize their stigmas with their own pollen, but also ensures that the bees have to pass by the stigmas on their way in.

It takes five months for the seeds to mature. The seed pods split open, allowing the seeds to be dispersed. The seeds are hydrophobic, meaning they float on the surface of the water, allowing them to easily be dispersed to new sites on water currents. I suspect they probably travel between lakes on the feet and feathers of ducks, too.

The Purple Pitcher Plant has been designated the official flower of Newfoundland and Labrador – its ability to persevere and thrive in harsh conditions a symbol for the province’s adaptable peoples.

Forest spirits

Speaking of blueberries… while at Maplewood Bog earlier this week I discovered these flowers growing in the forest. It’s one of those species that you recognize right away when you see it, because it’s so distinctive. They are Indian Pipe, Monotropa uniflora, also known as Ghost Plant or Corpse Plant for its pale, almost ghostly appearance, and are completely white because they lack any chlorophyll for photosynthesis. What you see growing above the ground is all there is to the plant – there are no leaves, just these flower stalks. It tends to grow in areas that don’t receive much sunlight, primarily dense forests, and chlorophyll would end up costing the plant more energy to produce there than it would be able to get back through photosynthesis.

So where does it get its energy, if it isn’t producing it itself? There are a number of non-photosynthetic plant species, and most of them are parasitic on another. One of the best known, perhaps, is the mistletoe of western North America, which hangs in the branches of its host tree in large clumps. Indian Pipe appears to be independent, but its host is actually hidden underground. It parasitizes a mychorrizal fungus, which itself is symbiotic with a tree. The fungus helps the tree to secure nutrients and water from the soil, more efficiently than the tree could do on its own. In turn, the tree provides the fungus with sugars that it made through photosynthesis high in the canopy, which the fungus is unable to make itself.

Where does Indian Pipe fit in? While each member of the fungus-tree symbiosis returns something to the relationship, the Indian Pipe is parasitic – it takes, without giving anything in return. It parasitizes the fungus by fooling the fungus into thinking it’s another part of the tree. The fungus gives the Indian Pipe sugars, nutrients and water, but of course the Indian Pipe doesn’t give the fungus anything in return. It can get away with this because it saps a very small volume of food relative to what passes between the fungus and the tree, so neither of the symbiotic partners feels any sort of drain.

I had seen many of these dried flower stalks in the forest on previous visits, but without any idea what they were. Now, having seen the Indian Pipe in the same area, I’m fairly certain that they’re last year’s Indian Pipe. After the flowers are fertilized, as the fruits begin to mature, the stalk straightens so that they become erect and upright. Eventually the plant material browns and dies, leaving woody, stiff stems topped with seed capsules.

So what about that mention of blueberries at the beginning? Indian Pipe is actually a member of the Ericaceae, the blueberry family, which includes blueberries and cranberries (of course), as well as rhododendron, azalea and arbutus, among others. Of the 3000+ non-photosynthetic plant species, the majority are in this family. The presence of Indian Pipe in a woodland usually means the soil is very rich and the forest extremely high-quality. If you spot the white flowers there, chances are there are many other unique and uncommon species to be found nearby.

Sweet blue treat

Life is full of simple pleasures, most of them free. One of mine is picking wild berries. Right now the blueberries are just coming into ripeness at Rock Ridge. Yesterday morning Dan and I visited the site for our fourth MAPS session. It was slow for birds, with just 11 caught in six hours of effort. Much of the rest of my time was spent snacking on wild blueberries.

We observed the short bushes in bloom back in May, and at the time didn’t know what they were – I’d only seen blueberry bushes once before, and at that time they were already fruiting. After some flipping through guides I finally settled on Lowbush Blueberry for these short flowering shrubs, even though the flowers I had photos of were mostly pink or pinkish, and Lowbush Blueberry flowers were supposed to be white.

Two months later, my identification was confirmed, at least to genus. Now, the actual berries are easy to ID, whether on the plant or off! There are two primary species of blueberry grown in North America: highbush and lowbush. Lowbush refers to Vaccinium angustifolium, which is also known as wild blueberry. Cultivated blueberries also go by the name of highbush blueberry, and are V. corymbosum. Both species are grown and harvested at a commercial level. As of the 2007 census, blueberries are commercially grown on 47,941 hectares (63,077 acres) of land in Canada, primarily in Quebec.

Besides these two, there are an additional 450 species in the genus Vaccinium, most of them found in the cooler northern hemisphere. Eighteen occur in Canada. The genus also contains related shrubs such as cranberries and huckleberries. Vaccinium species prefer well-drained, acidic soils that are often associated with rocky boreal or montane habitats, or bogs and heaths.

I’d been feeling pretty sure of my ID right until I sat down to start this post. In doing a bit more research on blueberries, and discovering that there were so many species, I began to think it may not be lowbush after all. Now I’m thinking it’s probably Velvet-leaf Blueberry, V. myrtilloides. Also called Canadian Blueberry, this species grows across Canada and the northeastern US. One website noted that flowers can be greenish-white or pinkish, which matches what I observed among our plants. However, there seems to be some confusion regarding the taxonomy of these two species, and they apparently will hybridize in areas where they occur together.

Blueberries grow from underground rhizomes, and can spread into large patches that sprawl across 30 feet (10 m) or more when conditions are good. The species is extremely fire-tolerant, growing quickly back from its roots after a blaze burns through the forest. In fact, where blueberries are are cultivated, they are often burned back to the roots to stimulate the next season’s growth.

A large section of the park was burned over (twice) about 80 years ago in the “Blueberry Wars” – disputes over picking rights of the wild blueberries growing on the land at the time escalated until someone either accidentally or intentionally lit a fire – perhaps in a fit of “if I can’t have them, you can’t either!”. The fires helped to shape the current landscape of the park by exposing the thin, parched topsoil to erosion.

The berries provide food for many species. They’re a favourite with bears, and in the north portion of the park there are definitely bears present. Although we haven actually seen the mammal yet, there are signs of their presence, such as flipped-over rocks (from looking underneath for invertebrates and other food items) or piles of scat. Bears are pretty wary creatures, and we make enough noise tromping through the bush that most likely one would depart long before we ever were aware of its presence.

Birds feed on the berries, too. I rather suspect they’re particularly enjoyed by thrushes, including robins, as well as catbirds and thrashers. In my experience, thrushes and catbirds are the messiest birds to band because their fruit-filled droppings usually leave a colourful stain on your clothing, and you can pretty much count on them to let loose on you at least once during the process.

Blueberries are loaded with vitamin C, and are often touted for their antioxidant properties. They were a common fruit in the diets of Native Americans, and were very versatile, eaten fresh or dried, in meals such as soups or meats, or on their own. The leaves could be used to make a medicinal tea. And of course, the berry juices make an excellent dye.

You can buy blueberry rakes that make harvesting much easier for commercial-scale blueberry crops, but there weren’t enough berries on our little shrubs to make such a tool necessary. I plucked them off by hand, and almost immediately popped them in my mouth. Mmm mmm. Hard to beat fresh-off-the-bush berries.