Sandra's Garden: proof not all Phlox are created equal

Species name: Phlox subulata

Common name: moss pink, moss phlox

Location: Sandra's garden

Last year I posted a blog about moss phlox, a native species we have in our garden that gets a little out of control in really sunny areas. It's a species native to North America, and one that occurs relatively commonly throughout its native range in bright and sunny, damp areas (despite also being drought-tolerant). It is much more common in the United States than in Canada. I knew this species was a popular garden plant based on what I've read about it, but I had never seen any of the cultivars created in greenhouses aside from the "normal" light purple type. Well, here's a spectacular demonstration of the "hidden" morphological variation that some plants contain. This variety of moss phlox was not created in the lab, but is a product of controlled breeding. Despite this, you would never find this variety of phlox in the wild unless it escaped from someone's garden.

So how do we "create" morphological variation in plants that is not typically seen in the wild? The secret is some patience, and a lot of time on your hands (it helps to have a greenhouse because it speeds things up a bit). Natural mutations in the wild create different alleles, or copies of a gene, that can show different morphologies if they have a chance to be expressed. Most of these mutations are what we call "recessive", which means you have to have two copies of the gene in order to be able to see the effect. This is good for the plant if the mutation is detrimental, but bad for gardeners if the mutation is something we want to see. In order to increase the number of recessive mutations in a population you back-cross the plants (breeding a daughter plant with a parent plant), or force inbreeding (forcing a plant with the gene to pollinate itself; sometimes this isn't possible in plants). After enough generations, which can be anywhere from 10 to over 1000 generations to get a pure line, you have a plant that shows only the allele you want expressed. Most garden plants are created this way; you back-cross over a certain number of generations until you get the desired effect in nearly all seeds grown. A huge downside of this type of selective breeding and back-crossing is that you're decreasing the genetic diversity in a population by selecting the alleles you want expressed and eliminating all others. For most plants this isn't a big deal; the ones grown in gardens are hardly reflective of the population as a whole in most cases, and if a virus or fungus or bacterium evolved that could eliminate an entire population of ornamental plant because of the inbreeding and a lack of resistance it wouldn't matter much. You would replant the next year with a different variety and hopefully the problem is solved. The big problem occurs when we start doing this with crop species, as we have been doing for over 12,000 years. Corn, for example, is so susceptible to disease that it is completely unable to survive without human intervention (not to mention we have eliminated the corn plant's ability to disperse its seeds; this is a slight problem if you're a corn plant but a major benefit if you're a human wanting to eat corn seeds). Soybeans in North America right now are on the verge of a massive population collapse due to the fungal disease called the soybean rust. It has recently shown up in the southern United States and is attacking soybean crops that have all shown to be susceptible to the disease. We grow the same variety in Canada (bred to have an increased seed size with an increased oil store in the seed), but are only saved from the attack of the pathogen due to our much colder winters that the fungus can't survive. It's only a matter of time before an entire year's crop is wiped out which could be absolutely devastating to the North American economy.

The previous blog post I did about this plant (which you can read about HERE) mentioned the smell of marijuana that this plant supposedly has, and the drug busts that have occurred as a result of people innocently growing moss phlox and having the smell waft in the wind. I did pick some leaves and crush them up; if you use your imagination I guess it smells like marijuana. I have a hard time believing that it would produce enough of a scent to convince someone there's a drug op in their neighbour's back yard, and I also have a hard time believing that someone would mistake the smell of phlox for the smell of marijuana!

Flamboyant Flamingo Flowers

Species name: Anthurium sp.

Common name: Flamingo flower

Location: UWO Greenhouse

The common name "flamingo flower" actually refers to an entire genus of plant species; Anthurium is estimated to contain 1000 or more species with almost all of the diversity of this genus existing in the South American tropics. There are a few exceptions, but none of them are notable. Approximately 3/4 of the species known in this genus are either threatened or endangered due to habitat loss, which makes the entire group incredibly vulnerable to extinction. These flowers are actually remarkably difficult to grow from seed in a greenhouse, so plants in some locations were hunted almost to complete eradication for the international tropical plant trade. Now, ornamental species are grown in greenhouses and propagated from cuttings, which means two things: first, they are no longer collected in the wild (or at least very little wild collection), and second the populations grown in cultivation are all genetically identical. This could be devastating for the flower trade (and once again for the wild Anthurium populations) if there was a pathogen that invaded greenhouses and flower plantations and wiped out all of the plants because they had no resistance.

The Anthurium flower, like the Jack-in-the-Pulpit flower (which you can read all about HERE), is a specialized type of flower. Anthurium species break all the rules when it comes to determining if a plant is a monocot or a dicot. Monocots have flower parts in multiples of 3s, and have long, narrow leaves with parallel veins. Dicots have flower parts in multiples of 4s or 5s, and have wide, broad leaves with net-like veins. Anthurium is a genus of monocots with broad leaves, veins that are somewhere between parallel and net-like, and have one inflorescence made up of tiny flowers that have their flower parts in multiples of four. Someone should tell these plants that they need to read more botany books to learn the rules! Anthurium flowers are made up of two parts: the spathe, or the white shield-like petal surrounding the rest of the inflorescence (its role is to attract pollinators), and the spadix which houses all of the tiny little flowers (thousands of them less than 1 mm across!). On the bright side, we've made up a new rule concerning the ways to tell monocots and dicots apart when the plants refuse to read books: whenever you see a plant with an inflorescence made up of a spathe and spadix, it's always a monocot!

The palm with the pony's tail

Species name: Beaucarnea recurvata

Common name: ponytail palm

Location: UWO Greenhouse

The ponytail palm is not a true palm, and its closest relative might surprise you. It is native to Mexico, but is used as an ornamental plant throughout much of the southern United States (it is cold-hardy to 6 degrees Celsius and is incredibly drought tolerant), South America, tropical southeast Asia, and Australia. This "tree", like true palms (one of which you can read all about HERE), is not actually a tree at all. It has no tissue called the vascular cambium, which is responsible for producing secondary xylem which is what we refer to colloquially as wood. If you don't produce true wood because you don't have secondary xylem, you can't be a tree! There are many monocots that masquerade themselves around town as being woody; bamboo, lucky bamboo (a completely different group of plants), palms, tree ferns and bananas all lack the ability to produce true wood (you can read all about bananas HERE). This doesn't mean that we can't use them as building material! All of these species produce a tissue type called sclerenchyma in great volumes which contributes to their stem stability (except banana; they produce collenchyma which is a tissue very similar to sclerenchyma. They also don't have a true above-ground stem!).

The ponytail palm, as mentioned, isn't a palm at all. It's actually a close relative of the asparagus family, and if I had of caught this plant while it was flowering it would have been much more obvious. The flowers produced by this species are almost identical to the flowers you would see if you let the asparagus in your garden go to seed. It's amazing the kinds of morphological variation you can get within a family!

The swollen base of the stem of this plant is designed for prolonged periods of drought. It almost acts as a water canteen, which can allow the plant to go for months without a significant source of water. If the plant went long enough, the base of the stem would start to shrink as the tissue and the water it contains starts to be reabsorbed by the plant. During the next major rainfall, the plant would reabsorb its water again and regrow the swollen stem base.

Not all Phlox are created equal!

Species name: Phlox subulata

Common name: Moss Phlox, Mountain Phlox

Location: Ontario

The Moss Phlox is a ground cover plant native to North America, with its natural range extending from Quebec to British Columbia and south towards Colorado and Tennessee. I would argue that now in certain habitats (like my back yard) it has become invasive, perhaps because of a decrease of natural competitors in the areas which it now grows. Almost all species of Phlox are native to North America (a few species, or only one depending on your definition of species, are native to Siberia) in some capacity, with overlapping ranges extending from East coast to West coast and from Alaska south to Florida. The variation in this genus of plants is a great example of "niche theory", which states that plants and animals evolved to specialize to a specific niche, and so "microhabitat" can be a leading contributor to the evolution of new species. This theory has been all but abandoned in recent literature in favour of other theories since it could never explain all the variation seen in an area by itself, but it's still a good theory used in conjunction with others to explain species distribution. The genus Phlox contains more than 65 species, being distinguished by their size at maturity (ranging from only a few centimeters tall to over a meter) and their flower colour. Horticulturalists have hybridized various species to produce new and unusual flower colours that would not have been present in large numbers in natural populations.

Other than a popular ornamental plant, Phlox species in general are not used for a whole lot. There are no species with any medicinal value (either historical or current) with the exception of Garden Phlox which is a powerful laxative. This should also suggest that it's a poisonous plant, and shouldn't be consumed! The analysis of the essential oils in the plant done by a lab in Denmark didn't show the plant to have any promise as one containing chemicals previously documented to fight cancer, slow the progress of AIDS or diabetes, etc.

One humorous side-note to this plant is that it supposedly (I've never noticed this phenomenon, but maybe it is not uniform across all species) has a very similar smell to that of marijuana and has caused the "backyard bust" of a few homes in England and the United States after neighbours reported the smell. I doubt the plant itself would be mistaken for marijuana since they differ drastically in appearance!

Thou shalt forget me not!

Species name: Myosotis sp.

Common name: forget-me-not

Location: Nova Scotia

One of the amazing aspects of the Acadia University campus is their arboretum and medicinal plants garden. Tanya and I spent a good couple of hours wandering around a relatively small corner of campus looking at their pond system (with bog, swamp and marsh areas that they had created), their native plant area, and their medicinal plant garden. The medicinal plant section was by far my favourite because it had so many unusual plants, most of which were historically used in native medicine or once used for extracts to treat a specific disease. They even had a wormwood plant, since that was once originally used to treat malaria!

The forget-me-nots were growing around one of the ponds, which leads me to believe this could possibly be the "true" forget-me-not, or Myosotis scorpioides (native to Africa), but there aren't enough identifying features in the photo to be able to tell for sure. The genus Myosotis contains about 50 different species, and almost all of them have the potential to become invasive under the right conditions. Forget-me-nots are popular garden plants in North America, since they are such an effective ground cover, especially in shady areas (which should lead you to believe even more strongly that they're invasive!). I remember planting the "mini kind", as I used to call them when I was 4 or 5, with my mom in our garden at the old house. More than 20 years later we were still pulling the stragglers out of the garden! Since the plants themselves were so short, it leads me to believe it was probably Myosotis alpestris that we were planting, or the Alpine forget-me-not which is the state flower of Alaska. For anyone that's counting petals, this plant is indeed a dicot!

Unlike other spring wildflowers I've blogged about so far, forget-me-nots do not produce rhizomes for underground energy storage. Instead, they have a diffuse fibrous root system so they act as effective erosion-control plants by holding in the soil. This root system is also what allows them to invade riverbanks (also called the "riparian zone") and out-compete native plants. It also produces more seed at a much quicker rate than most of our native plants that grow along riverbanks, which helps contribute to their success as an invasive species.

The origins of the common name of this plant are quite diverse, but I'll share my two favourites. The one my grandma used to always tell me (she had a story for everything...true or not, they were always interesting!) was about a knight in shining armour that was walking by the river with his princess when he bent down to pick her some flowers. The weight of his armour pulled him into the river, but before he drowned he threw the flowers at the princess and yelled "forget me not!" The Freemasons also used this flower as a symbol in the 1920s to not forget the poor and desperate people in Germany. The flower still has tight ties with modern Masons, often being worn as a symbol that those that have died are gone but not forgotten.

Forget-me-nots have been used (and are actually becoming more popular) in herbal medicine around the world as a treatment for chronic nosebleeds and lung issues. I would strongly suggest against the use of this plant for these purposes, however, since they potentially contain high levels of chemicals called "hepatotoxic pyrrolizidine alkaloids," which attack the liver and cause liver failure and can cause cancer. There is conflicting evidence on whether all species of this genus contain these alkaloids, but it's always better to be safe than sorry!

Peekaboo! I see you!

Species name: Arisaema triphyllum

Common name: Jack-in-the-pulpit, bog onion, brown dragon, Indian turnip

Location: Ontario

Jack in the pulpit flowers are great examples of exceptions in the plant world, which is one of the reasons why I like them so much. It is another example of a native eastern North American plant. We have these growing in our back yard, which confused me at first (like they do many people) since I mistook them for poison ivy and ripped out all of the leaves one year (with gloves on!). The leaves of poison ivy and jack in the pulpit are both what are called "trifolate", which means there are three leaflets coming out of each "leaf point" on the stem. Once this plant starts to flower, however, is very obvious that it's not poison ivy! Silly me. Like the last plant in this blog, hyacinth, jack in the pulpit also grows from a corm.

One of the amazing things about this plant is just how variable it can be depending on environmental conditions, and what type of genetic variation it contains. The flowers themselves can range in size from 12-36 cm tall, and can be anywhere from pure green (like in the photo) to green with dark brown (almost purple) stripes. The "jack" on the inside can also be bright green or dark purple-brown, or anywhere in between. The plants themselves can be from 30-65 cm tall, depending on nutrient levels of the soil.

In general, a good rule to use to figure out if a plant is a monocot (in other words, most closely related to grasses) or a dicot (in other words, most closely related to an oak tree) is by the shape of their leaves and the number of flower parts. In general, monocots have long and thin leaves with parallel veins and flowers with flower parts (petals, sepals, stamens and stigmas) in multiples of three. Dicots have broad leaves with net-like veins and flower parts in multiples of either fours or fives. Jack in the pulpit, then, seems to be a dicot. Its leaves are broad and have net-like veins, and unless you have a very powerful hand lens it's impossible to tell if flower parts are in multiples of 3s or 4-5s. Unfortunately...that would be incorrect. This is a monocot! One unusual group of monocots is the family Araceae, which includes the peace lily (a common ornamental plant, often used as an aquatic plant in wedding centrepieces). They have broad leaves with (mostly) parallel veins (but some are cross-wise) and a specific type of flower called the spathe and spadix. Here, "Jack" would be the spadix and his pulpit would be the spathe. If you zoom in on the spadix, you would see that it's actually a multi-flowered flower head (called an inflorescence), with each little facet on the spadix being one flower. Neat!

But, of course, the uniqueness of this plant doesn't stop there. This is also a great plant to demonstrate all of the unique evolutionary mechanisms plants have derived to avoid self-pollination or inbreeding. There are separate male and female flowers on the spadix, but never both at the same time. Usually the plant starts with predominantly male flowers (if there are female flowers, they are not mature yet) that are producing pollen. Flies are attracted to the spadix because they are much warmer than the ambient air (thanks to the spathe), and they have a rather...unpleasant smell. The fly is covered in pollen, then travels to another flower. If the plant plays its cards right, the next flower will be predominantly female flowers (if there are male flowers, they are no longer mature) which are receptive to receiving pollen. The fly deposits the pollen onto the stigmas, and pollination occurs. Even neater!

This plant is absolutely toxic if consumed raw (it contains calcium oxalate crystals which can perforate the digestive tract), but is actually often cooked as a root crop like you would cook potatoes (but boiled a bit longer because they're much tougher) and eaten. I have never tried it so I can't vouch for what it would taste like, but I can't imagine it would be too flavourful. Native North American people often used this plant as a medicine to treat sore eyes, rheumatism, bronchitis, snake bites, and to induce sterility. Whether or not it's an effective treatment against any of these I have no idea. I wouldn't recommend experimenting.