Can The Cat Come Back?

Species name: Typha angustifolia

Common name: Narrowleaf Cattail

Location: Ontario

There is a bit of debate as to where this species originated, but I'm going to give it the benefit of the doubt and say it's a North American species that has been introduced to Europe. It's entirely likely it happened the other way around; the species is so broadly distributed across the Northern Hemisphere that it has become difficult to tell where it "has its roots," so to speak. All cattails are what are called "obligate wetland" species, meaning that they require the wetland environment in order to grow. This doesn't mean they need to have the base of the plants submerged; it just means that they require very loose, very wet soil to grow with poor drainage. They have adapted throughout the millennia to be able to survive having water-logged roots, where most plant species would essentially drown. Even though roots grow underground, they still require oxygen to survive!

Cattails have a long history of use in North America, from food to clothing and baskets. Almost every part of the cattail is edible, with the youngest parts being favoured. Even though the plant doesn't ever grow true wood, it still can get "woody" (like bamboo; that's not real wood, either) and difficult to chew. The underground rhizomes can be eaten like potatoes, and were once thought to be "the next great agricultural crop" when the whole world floods after the ice caps melt. This idea was rather quickly abandoned since, well, they're not all that tasty. But in a pinch they're actually quite nutritious, even more than a potato or sweet potato. If you're ever lost in a wetland and about to die of starvation, go dig up some cattail rhizomes! Just make sure you cook them; they're incredibly unpalatable when raw, and some even report they might be mildly poisonous. Best not to risk it.

I remember when I was a kid we used to go pick the green leaves to make grass skirts out of for "Hawaiian Day" at day camp. I thought we did that only because we don't have palm trees in Canada, but it turns out that they have been used for exactly that purpose for hundreds of years. Granted, they're not called "Hawaiian grass skirts" when you're not in Hawaii (or using grass...). The reeds are also fantastic for making baskets. Weave the green leaves while still fresh, then allow to completely dry. The basket will be lightweight, can get wet without falling apart, and floats. Great for collecting cattail rhizomes! The leaves can also be woven into a flat mat, laid on a flat rock then pounded flat with a smaller rock. Once all of the leaves have been split open and the fibres have all been mashed together, the sheet is let dry. The dried sheet can be written on exactly like paper would have been, but this material is much more durable. It's actually the exact same method that ancient Egyptians used to make papyrus, where we get the English word "paper". I'm not sure whether the method for making paper this way was independently discovered in North America, or whether word had spread from Europe during the early days of exploration.

Due to disappearing wetland habitat around the world, all cattails are at risk for population decline. To compound this fact, there are some "facultative wetland" species (species that don't require wetlands to survive, but can grow perfectly well there) that outcompete cattails for resources and habitat space. Unless we actively start ripping out invasive aquatic plants and conserve wetlands, this species is at a real threat of disappearing.

Water Lettuce is never eaten by Water Cows

Species name: Pistia stratiotes

Common name: water lettuce

Location: Ontario

The origins of water lettuce are unknown, but this plant was first discovered in Africa near Lake Victoria. It's presumed native to that location, but it could have been introduced there previously. It is now present in just about every waterway in tropical and subtropical area around the world, either through accidental human introduction, purposeful human introduction, or natural spread. It has become dangerously invasive in areas that don't have sub-zero temperatures during the winter, since it is not cold tolerant. Thankfully, this means that we have mostly escaped in Canada from having to worry about this long-term; with milder winters there is the serious threat of this absolutely taking off.

This is a very popular backyard pond aquatic plant, since it is better at competing for resources than algae that usually takes over a pond. Should a pond be properly balanced, the chance of algae being able to take over a pond is actually slim to nil. Over-feeding fish, having too many fish, too many plants, not enough water aeration, and a pond that is too shallow can all lead to a biological imbalance, which can in turn lead to an algal domination.

This plant has been especially successful at dominating waterways in Florida, where it has been contributing to the mosquito population boom. Mosquitos require standing water in order to lay their eggs, as their larvae are aquatic. Laying eggs under the surface of the bottom leaves of water lettuce provide the developing eggs with a sheltered environment, and provide the newly hatched larvae with a safe place to develop after hatching. The larvae actually create a siphon tube from where they live on the root of the plant up to the surface of the water so that they can get oxygen. A neat adaptation, but one that makes it incredibly difficult to control mosquito populations where water lettuce is abundant.

Is the population of pickerelweed in a pickle?

Species name: Pontederia cordata

Common name: pickerelweed

Location: Ontario

This species of aquatic plant is native from southeastern Canada (Ontario, Quebec, New Brunswick, Nova Scotia) all the way south to southern Argentina in South America. There have been arguments by plant taxonomists in the past about whether the South American populations should be considered the same species as the North American populations, and so many Latin synonyms have been given to this plant in the past. DNA sequencing has shown that this plant is the same species throughout its entire range, but with small divergent sub-populations. These sub-populations may one day become their own species with enough time to genetically diverge from the parent population, but this has not occurred yet (since all sub-populations can still breed with their parent population). Due to land use change throughout much of the native North/South American range of this species, the chances of these sub-populations having enough time to genetically diverge from the parent population to produce distinct species is pretty slim. In fact, back yard garden ponds are some of the richest sources of this plant, with it escaping back into boggy and swampy areas if left unattended (it is a very vigorous seed producer!). Again unfortunately, it is not a very good competitor with invasive species (which we have many, many invasive species in North American wetlands) so it rarely establishes a new population for long.

Since this species of plant can grow submerged in water like rice can, it, like rice, requires some sort of mechanism in its tissues to be able to transport gas from where it is absorbed in the leaves to where it is needed for growth in the roots. To do this, the plant forms a special type of tissue called "aerenchyma," which looks a bit like empty honeycomb. The large, empty cells are used to store oxygen and carbon dioxide so the plant doesn't suffocate under water. A neat adaptation! The flowers also have a special adaptation to attract bees that you can see in the third picture, that yellow dot on the top petal. Once the flowers are pollinated by bees, the plant undergoes a process called "geotaxis," which refers to the entire inflorescence stalk bending to submerge the developing seeds under water (peanut plants also do this with their developing seeds; this is why peanut shells always have a bit of dirt left on the outside!). The seeds then finish maturing and are released into the muck at the bottom of the pond. This is also a pretty incredible adaptation; without a prolonged exposure to water, the seeds cannot germinate.

With the exception of ornamental value, there is no other major use of this plant by humans.

Queen Victoria's Waterlily

Species name: Victoria amazonica

Common name: Amazon waterlily, Royal waterlily

Location: Dave's Garden -- jeri11

The royal waterlily is native to the Amazon Basin in South America, is the largest waterlily in the world, and is named after Queen Victoria. Since today is Victoria Day in Canada, I figured there would be no better "plant of the day" than this one! Most species of plants can be bred by humans to have two different colours of flowers from the same species, but the two pictures above are actually of the same flower on two different days; the flower actually changes colour on its own. Unfortunately, I've never seen this plant in person so the best I can do are pictures from Dave's Garden from people that have actually seen it.

This plant has an incredible life cycle, being pollinated by only a single species of beetle. The beetle is attracted to the scent of the white flower that opens on the first night, which is often said to be chemically equivalent to the sex chemicals emitted by those beetles. Once the flower senses that there is at least one beetle that has landed on the flower, it closes relatively quickly to trap the beetle inside. The beetle fights to get out of the flower until the next night when the flower re-opens, getting pollen all over itself. On night two, the flower opens again to release the beetle and this time it is a stunning colour of pink. The colour change is also accompanied by a change in the sexual parts of the flower that are active: the flower stops producing pollen and is instead receptive to pollen on the stigmas. If a beetle visits one of these pink flowers after visiting a white flower, cross-pollination occurs.

The flowers aren't the only impressive part of this plant. The leaves are also some of the largest leaves in the plant kingdom, becoming almost 40 cm across and supporting the weight of a small child when mature. On the underside of the leaves are very large, dangerous spines which would seriously injure any animal (human or otherwise) to come in contact with the leaves. As you can imagine, this is a very effective deterrent of herbivores!

Happy Victoria Day!

Is the fleur-de-lis really an iris?

Species name: Iris pseudacorus

Common name: Yellow Flag Iris, Yellow Flag, Yellow Iris

Location: Ontario

The yellow iris is an aquatic plant native to Europe, Asia (western) and Africa (north coast). It thrives in aquatic conditions, especially where the water is of low pH (it does very well in bog-like conditions where many other aquatic plants cannot survive), the plant is partially submerged, and the rhizome experiences constant anoxic (oxygen-deprived) conditions. In North America, these are the reasons why (coupled with the fact that it is a very popular pond and garden plant) it has the potential to become invasive. I would argue (and I think others would, too) it has become invasive already in certain areas like the Byron/Sifton Bog in London, where it can out-compete native aquatic plants for resources. Some regions in North America have banned the sale and planting of this plant due to its potential to become invasive, but most gardeners and landscape companies continue to plant it unaware of its potential for environmental destruction. Because Ontario does not recognize this species as invasive, I have not highlighted the invasive box.

Aside from being potentially invasive in non-native habitats, this plant is incredibly important throughout its native range for other species. It can form a very dense cluster of vegetation, so is prime breeding ground for fish, frogs, and birds. There is even one species of bird in Scotland that is endangered called the Corn Crake that uses yellow iris patches as breeding grounds. The bird is a ground-nester, where it lays its eggs directly in a nest made of grass leaves in a hollow in the dirt. This is especially easy in a patch of yellow iris since the leaves are so easily detached from the rhizomes underground.

Like all irises, the juices from a cut rhizome are irritating to the skin, so gardeners planting this species should wear gloves (especially those with sensitive skin). Historically, this plant was used medicinally as an emetic. More recently, it was discovered that this species is especially effective at taking up heavy metals through its root system and has this has led to experimentation with this plant as a water clarifier.

Many have argued that the fleur-de-lis (used on the Quebec flag and in Quebec and France as a decorative symbol) is a stylized version of an iris (despite the name "fleur-de-lis" meaning "lily flower"). I would say based on the name alone it's more likely designed from a yellow or white lily than an iris. The fleur-de-lis doesn't look much like either, does it?