Tuesday, June 30, 2015

Black-Eyed Susan - Rudbeckia hirta - Rudbeckie

I have posted briefly about this flower before. Today I will talk about it a bit more in-depth. One of the first things I will say about this species is that it is native to many parts of North America (North American range map here), including Quebec (where the previous post and this post's photographs were taken), but that it has been introduced to British Columbia, Alberta, Manitoba, New Brunswick, Nova Scotia, PEI, and Newfoundland & Labrador [1], likely as an ornamental. This plant can be weedy in some situations [2]; the classification likely reflects this plant's ability to spread and colonize new areas.

Rudbeckia hirta - in the insect gardens at the Montreal Botanical Gardens
This species is also frequently referred to as Rudbeckia serotina, but this is no longer an accepted taxonomic designation and R. serotina is considered a synonym of R. hirta (var. pulcherrima) [3,4,5].

Rudbeckia hirta flower bud
Rudbeckia hirta is a useful plant for rehabilitating roadsides, as it is a good plant for erosion management [6]. This flower is also a minor source of food and shelter for a variety of song and game birds [2,6].

Rudbeckia hirta flower
One variety of Rudbeckia hirta is a biennial plant [6,7]. This means that it lives for two years and has a distinct growth phase for each (a bit like Verbascum thapsus, which I will post about at some point when I get some good photos). The first year, it produces a rather unprepossessing basal rosette of leaves, and the second year, the flowering stalk we are familiar with. After flowering and going to seed, the plant dies and the seeds start the whole process over again.

Other varieties of Rudbeckia hirta are simple annuals; they sprout from seed, bloom, go to seed, and die back to start over again.

Rudbeckia hirta flower visited by syrphid fly
This species provides nectar and is attractive to bees and butterflies [8], which would explain why it had been planted in the insect garden at the Montreal Botanical Garden. Also, the seeds are attractive to birds [8].

Rudbeckia hirta flower visited by syrphid fly
It sure is a beauty, isn't it!

Monday, June 29, 2015

Dragonflies in the City! - Odonata - Libellules

In spite of being stuck in the city, I have actually seen a few dragonflies. They are of two rather common species. The first one, an immature male Plathemis lydia (common whitetail) dragonfly who was not shy; he stayed quite still and seemed unconcerned about me and my camera:

Plathemis lydia immature male
Another dragonfly I saw was a mature male Libellula pulchella (twelve-spotted skimmer), who was hanging out in the insect garden at the Montreal Botanical Gardens:

Libellula pulchella mature male
This one also was not very shy, holding still and steady while I stuck my camera in his face.

There are also a few of the much shyer Ennalagma civile (familiar bluet damselfly), one of the most widespread and common North American damselflies. This one was photographed at the insect garden in the Montreal Botanical Gardens.

Ennalagma civile

Sunday, June 28, 2015

Oxeye Daisy - Leucanthemum vulgare - Margueritte

This is perhaps one of the most-recognized flowers around (though there are quite a lot of flowers that go by the common name 'daisy'). Leucanthemum vulgare is native to Europe & Asia [1,2,3] and was introduced to North America in the 1800s as an ornamental plant [2,3]. I have very briefly posted about this plant before.

Leucanthemum vulgare inflorescence
Since its introduction, Leucanthemum vulgare has spread over most of North America (US range map here, Canada range map here). Although it is pretty, this species is listed as an invasive species in the US [4], and classified as a noxious weed both federally and in most provinces where it is found in Canada [5]. In Canada, the noxious weed classification indicates that the plant is invasive and disruptive of native plants and ecosystems on a large scale. I do not recommend this plant to gardeners.

Clump of Leucanthemum vulgare
Some parts of this plant are edible [3,6]; I have eaten the young leaves before and they are rather spicy/carroty.

Leucanthemum vulgare inflorescence
This species is pollinated by bees, flies, beetles, wasps, and butterflies [2].

Saturday, June 27, 2015

Leaf-Eaters!

Today we have a bit of a change of pace. I have a few photos of leaf-eaters, and I'd like to talk about plants and predation.

So plant reproductive success and growth is heavily affected by coevolutionary relationships with pollinators. I write about this all the time, as it is one of my main areas of interest. But pollination is not the only way in which insects interact with plants -- and the flowers aren't the only part that can end up attracting insect attention.

While I was wandering around last week, I managed to get a few photos of some members of the Orthoptera (an order of insects that includes grasshoppers, locusts, katydids, etc). These are usually plant predators.

Take, for example, this funky-looking guy:

Katydid nymph on Lotus corniculata - notice the holes in the two petals in front
This is a katydid nymph (nymphs being one of the young phases of the life cycle of many insects; as it matures it will develop the armoured appearance of an adult katydid). Katydids feed on plants: adults feed particularly on the leaves of woody plants (ie trees, shrubs), but the nymphs are known to feed on herbaceous plants. So this buddy here was probably hanging out in the grass and on the flowers because they're food.

Similarly, I also managed to get a photo of this guy:

Grasshopper
Grasshoppers also feed on plants.

So you might look at the grasshoppers and katydids, and at other herbivores (eg aphids, deer) and think to yourself: well, that's a stacked match-up. The plants can't get away.

And you'd be right that the plant doesn't have running away as an option (although some do grow in places or times that are less accessible to herbivores). But plants have other defense mechanisms against herbivory that are pretty awesome.

Some plants develop permanent or constant physical defenses such as thorns, which make them unpleasant or difficult to consume. Or they produce poisons that deter predation.

And then there are a whole lot of complex chemical things that plants can do to deter herbivory. Some plants, when they start getting eaten, will produce volatile organic chemicals which will in some way deter the herbivore: some will be directly unpleasant to the herbivore, some will prevent herbivore eggs from developing correctly and hatching (thereby reducing their numbers and the damage they can do), and others will even attract the predators of the herbivores (basically recruiting other insects as enforcers).

So although it looks like an uneven matchup, plants are not nearly as helpless as they might seem.

---

Today's material primarily sourced from the wikipedia page on the topic of plant defense against herbivory and from my lecture notes. I've really only just scratched the surface here, so if you're interested I would highly recommend reading the wiki and some of the sources linked on that page.

Friday, June 26, 2015

Crownvetch - Securigera varia - Coronille variée

Today we have yet another introduced species in the family Fabaceae (legume family), this time introduced not as a fodder crop or an ornamental, but for ecosystem management: Securigera varia (aka Coronilla varia, crownvetch) has been introduced to North America primarily as an erosion control plant [1,2,3,4,5,6]. Securigera varia is suitable for this purpose because it spreads rapidly (both through seeding and through vegetative propagation by root spreading) and forms a dense root system [1,2,3,5]. Like many members of the Fabaceae, Securigera varia is a nitrogen-fixing plant [2,4,5,6].

Securigera varia inflorescence
Since its introduction to North America in the 1950s, Securigera varia has spread across much of the continent (US range map here, Canada range map here). Unfortunately, those traits which make Securigera varia a suitable erosion control plant can also make it a problematic invasive plant [1,2,3,5,6]. This plant will tend to squeeze out other plants, disrupting ecosystem functioning [1,2,3,4,5,6].

Securigera varia foliage resembles that of Vicia cracca (cow vetch):

Securigera varia foliage

Thursday, June 25, 2015

Bird's-Foot Trefoil - Lotus corniculatus - Pied de poule

Today, I continue in my recent theme of posting about Fabaceae (legumes) introduced to North America as forage plants (see: Galega orientalis (fodder galega)Medicago sativa (alfalfa)Trifolium pratense (red clover). This time, I'm going to talk about Lotus corniculatus (bird's-foot trefoil).

Lotus corniculatus inflorescence
This species is native to Europe, Asia, and Africa [1], and has been introduced to most of North America (US range map here, Canada range map here), primarily as fodder (livestock animal feed). It is a member of the family Fabaceae (legumes) and, like most members of this family, is both a good feed plant and a nitrogen-fixing plant [1,2,3] (nitrogen fixing: removes nitrogen from the atmosphere and puts it into the soil). This plant can become invasive and choke out native plants in some places, especially grasslands [1,2,4].

Dense patch of Lotus corniculatus
Unlike many Fabaceae used for fodder (including Medicago sativa and Galega orientalis), Lotus corniculatus doesn't cause bloat in cattle and so is a desirable fodder crop [1,2].

Lotus conriculatus inflorescence
This plant reproduces primarily through its roots [1], can occasionally self-pollinate [5], but is mostly pollinated by large bees [5], which must be strong enough to pull apart the flowers to access pollen and nectar [5]. Lotus corniculatus produces large amounts of nectar and so is a desirable honey crop [5].

Wednesday, June 24, 2015

Wild Strawberry - Fragaria virginiana - Fraise sauvage

I had more or less resigned myself to not getting to enjoy some delicious, delicious wild strawberries this year, though they are the best strawberries. That's because I am stuck in the city for most of the summer and certainly for the last two weeks of June which tend to be the season for them.

Fragaria virginiana in bloom at the lake mid-May
There have been a few strawberry plants here and there, and I was at the lake over the Victoria Day weekend and able to snap a few photos of the flowers (which I talk about in a previous post about the evolution of separate sexes in plants).

Fragaria virginiana - flower that I photographed at the lake this spring
Though I had even spotted a few Fragaria virginiana here in Montreal, most of them were in regularly-mown lawns so my hope of getting any berries were slim to none. I spotted this plant and its fruit at one point mid-June, but when I returned a few days later the fruit had disappeared:

Fragaria virginiana fruit - almost but not quite ripe
So, as I noted above, I had pretty much given up on the hope of eating any of the tastiest strawberries in existence (hands down, no contest, I will hear no disagreement on this point). Imagine my surprise then, when, during a stroll this afternoon (free from work for the St-Jean Baptiste), I happened across a patch of strawberries fresh and ripe and unmown!

Naturally, I set to work immediately on picking them. A few minutes' work netted me this rather nice little haul here:

Fragaria virginiana - a lucky find
And I devoured them with great gusto. As far as I can determine, there are only two possible reasons I was lucky enough to beat somebody else to these: 1) nobody else noticed them, or 2) nobody else was shameless enough to eat strawberries picked in a cemetery. Yep. These were in the Notre-Dame-des-Neiges cemetery (no, not around any graves, I wasn't crawling about between tombstones in front of mourners). At any rate they were delicious. I believe that their deliciousness is entirely worth the effort, small though they are.

I regret nothing.

Saturday, June 20, 2015

Native Edibles : Flowering Raspberry - Rubus odoratus - Ronce odorante

Blooming right now are a number of the cane berries, a variety of species in the very large and economically important genus Rubus, which is in the family Rosaceae (rose family).

This genus has distinctive fruits which are aggregates (clusters that are kind of stuck together) of drupelets (fruit that consist of a fleshy layer surrounding a pit, which is composed of a shell exterior and a seed inside). This genus includes blackberries, raspberries, other cane fruit, and the star of the day: Rubus odoratus (flowering raspberry).

Rubus odoratus inflorescence
Rubus odoratus is native to North America, but has spread beyond its native range. Originally found in Ontario & Quebec [1], and in the eastern US [2], it is now also found in Nova Scotia and New Brunswick [1]. This species' conservation status is secure in its Canadian range [1], but it is endangered in Illinois and threatened in Tennessee [2].

I have posted about this plant before, but not in much detail.

Rubus odoratus broader view
Rubus odoratus has been introduced to Europe and is considered naturalized to several areas there now [3,4]. It success in areas outside of its native range is potentially attributable to some weedy characteristics, notably its seed set, which is large and composed of small, easily dispersed seed, and its rapid vegetative growth [5]. It was likely brought to areas outside of its range for its ornamental value [3]: it has large, attractive maple-like leaves and a long flowering period [3,6].

I cannot find much information about its pollination, but one usually reliable source indicates that this plant is of special value to pollinators (especially native bees), attracting large numbers of native bees, bumble bees, and honey bees, and that it provides shelter or nesting sites to some species of native bee [6].

Rubus odoratus visited by a Bombus sp. worker - note how full her pollen baskets are! She must have returned to the colony shortly after I took this shot to deliver her haul
I am in disagreement with several sources that state that the fruit of this plant is flavourless [5] or insipid [6]. I find the fruit tasty, if dry and a bit fuzzy on the tongue.

Friday, June 19, 2015

More Fabaceae: Red Clover - Trifolium pratense

So this week's posts have accidentally ended up with a unifying theme: I've been posting a lot about introduced species in the Fabaceae (legume family) brought to North America as feed crops. Primarily, I suppose, because a lot of the species in this family are just coming into bloom now, so I have a lot of them queued up for posting.

Trifolium pratense inflorescence
Trifolium pratense (red clover) is native to Europe [1,2,3] and is now found in most states, provinces, and territories in North America (US range map here, Canada range map here). This plant was originally brought to North America by settlers as a forage crop (food for grazing livestock) [1,2]. It is also, like many Fabaceae, a nitrogen-fixing plant [1,2].

Trifolium pratense inflorescence
This plant can frequently be found outside of farms, especially in disturbed fields, roadsides, parks, and unmown grassy areas [3].

Trifolium pratense general view
Trifolium pratense is edible and often used to make tea (I make herbal teas with it myself, it is sweet and tasty) [2], but because it is estrogenic [1,2] should not be consumed excessively by anyone with estrogen-sensitive conditions e.g. breast cancer [2] and is known to cause various health problems in livestock when improperly managed [4]. It has been touted as a treatment for a number of ailments but at present there is insufficient or conflicting evidence for most of these claims [5].

One rather pretty part of the plant that people rarely notice is the leafy casing that forms at stem junctions, and which looks rather like stained glass:

Trifolium pratense

Thursday, June 18, 2015

Bugs, Bugs, and More Bugs!

The butterflies are becoming more abundant lately. There are lots of nectar-producing flowers blooming now, so tons of food. Over the weekend I managed to get photos of two more butterfly species: Epargyreus clarus (silver-spotted skipper), and Phyciodes cocyta (? sometimes it is difficult to tell apart species in this genus but I think it's Phyciodes cocyta based on what appears to be an orange tip on the antennal club, which is apparently a distinguishing feature of this species [1]), the northern crescent.

Phyciodes cocyta (?)
Both of these species are native to North America. Phyciodes cocyta is one of Canada's most abundant butterflies in its range [1].

Phyciodes cocyta (?)
Epargyreus clarus is Canada's largest skipper [2], being about as big as a monarch or tiger swallowtail. It is not particularly abundant [2], so I was lucky to have run into a group of them (there were four that I saw in a few minutes). This species can be somewhat colonial [2], so it's unsurprising that there were a reasonable number of them in the same area.

Epargyreus clarus - collecting nectar from Vicia cracca
I also managed to get a very nice shot of a ladybug, which I believe is Coccinella septempunctata (seven-spotted ladybug), a species native to Europe but which has been repeatedly and extensively introduced in North America as pest control against aphids [3].

Coccinella septempunctata

Wednesday, June 17, 2015

The World's Favourite Forage Crop: Alfalfa, Medicago sativa

So I recently wrote about Galega orientalis, an introduced species that has been brought to North America as a forage crop (forage : in this case, referring to use for animal feed).

Medicago sativa
I have since discovered that there is Medicago sativa (alfalfa) in the forested side of the Notre-Dame-des-Neiges Cemetery. This plant has been introduced all over the world, including in most states and provinces (US range map here, Canada range map here). In the wild, this plant is a documented source of food for non-livestock animals [1], including antelope, deer, elk, Canada geese, and grouse [2]. Though this plant is widely distributed, it isn't listed as invasive. Note, however, that it is considered weedy in parts of the US [1,2], but is not included in weed lists for Canada [3].

Medicago sativa inflorescence
Medicago sativa, like G. orientalis, is a member of the Fabaceae (legume family), and like many members of this family it is a nitrogen-fixing plant [2,4,5].

Medicago sativa is considered the oldest forage plant [2,4], and is also the most widely used forage crop today [4,5]. It is so greatly favoured for the nutritional quality of the hay it produces and for its high yield by acreage [4,5].

Medicago sativa inflorescence
This plant can be used for grazing rather than haying (grazing : letting livestock feed from the plant directly in the field - haying : growing, cutting, and processing the plant for feed), but because in certain life stages it can cause bloat [2,4,5,6], grazing must be controlled with care.

Medicago sativa inflorescence
Although alfalfa (unsprouted seed) is often touted as a treatment for a variety of human ailments, there is insufficient evidence to support these claims [7], and some of the compounds found in alfalfa (unsprouted seed) are likely harmful to humans if consumed long-term [6,7].

Medicago sativa is primarily pollinated by a solitary bee in the Megachilidae (leafcutter bees), Megachile rotundata (alfalfa leafcutter bee), because pollination using Apis mellifera (honeybees) requires large numbers of naive (young) bees because they are not actually capable of obtaining the reward from this flower due to its shape, so they learn quickly to avoid it [5]. Although large numbers of naive bees are used to pollinate alfalfa in places, Megachile rotundata is increasingly preferred [5].

Monday, June 15, 2015

Introduced Species: Snails - Cepaea spp.

So I've noticed one thing about Montreal's fauna that's quite different from the upper Gatineau: extremely abundant relatively large snails. They are Cepaea hortensis (white-lipped snail) and Cepaea nemoralis (grove snail).

Cepaea hortensis - notice that the shell margin at the lip of the shell is pale
Both species are native to Europe and have been introduced in North America. I have found their abundance here in Montreal quite striking, as until coming here I had never seen snails of this size anywhere I had been in Quebec or Ontario.

Cepaea hortensis
Like most gastropods, this species are both hermaphrodites (but still have to mate with others to produce viable eggs). They are also among the species which produce a "love dart" -- essentially a sperm-filled spike that is shot into the body of another snail during mating. This dart actually does pierce the body of the other snail. Violent! ... Reproduction can be a very strange process indeed.

Distinguishing the two closely-related species without dissecting them is not 100% accurate -- while generally Cepaea hortensis has a white or yellow lip to its shell and Cepaea nemoralis has a brown lip, this isn't a perfect correspondence, so it is possible (but unlikely) that these individuals are misidentified.

Cepeaea nemoralis - notice that the shell margin at the lip (opening) is brown
Aside from the lip colour difference, both species show quite a lot of shell pattern polymorphism, varying in base shade from a pale creamy colour to a richer yellow, and having a variable number of brown stripes.

Sunday, June 14, 2015

Fodder Galega - Galega orientalis

Every now and then I find a plant I wasn't expecting. This is certainly the case for this charming beauty, found along one of the trails in the Mont-Royal park, which I confess to being intrigued about, because I wonder how it ever got there:

Galega orientalis
This is Galega orientalis, a plant native to Russia & environs [1,2]. It is a member of the Fabaceae (legume family), and like many plants in that family is a fixer of nitrogen [1] -- nitrogen-fixing plants are plants which take atmospheric nitrogen and put it into the soil; this is a very useful trait in agriculture (as nitrogen is one of the essential nutrients for plant growth), but not the primary agricultural use of this plant.

Galega orientalis inflorescence - raceme shape
So why was I surprised to find this plant in the park? Well, the plant has been introduced to North America as a fodder (animal feed) plant [1,2,3,4], so it's not surprising to find it somewhere on this continent so much as it is surprising to find it in the Mont-Royal park, relatively distant from any farms or agricultural operations.  There was only the one plant that I could find and it certainly wasn't there as animal feed. My guess would be that it was brought in on a dog's fur or on the clothes of a person involved with or near agricultural operations with this plant.

Galega orientalis inflorescences
G. orientalis is an excellent fodder plant, as it is relatively high in protein and other valuable nutrients [1,5], as well as hardy and tough, making it suitable for tougher conditions. Work is ongoing to determine the best cultivars for introduction of this plant in agriculture as far north as Alaska [4].

Galega orientalis flowers
G. orientalis is a perennial shrub with upright, non-climbing growth habit [3,5,6]. This plant is a good nectar-producer and is pollinated by bees [1,5].

It's also quite a beautiful plant. I'm often quite charmed by plants in the Fabaceae, many of them are quite beautiful. Of course, a great deal of the world agrees with me: the Fabaceae are not only popular in agriculture but in gardening all over the world; sweet peas, among others, are favourite ornamentals from this family. One of the distinctive characteristics of this family is the bilateral symmetry of the flowers (as opposed to the radial symmetry seen in many other families):

Galega orientalis : bilaterally symmetric flowers

Saturday, June 13, 2015

Canada anemone - Anemone canadensis - Anémone du Canada

In the Mont-Royal park recently I stumbled across a patch of Anemone canadensis (Canada anemone, Canada windflower). This plant is native to the area. US distribution map here, Canada distribution map here. This plant is historical in Kentucky, endangered in Connecticut and Tennessee, and endangered/extirpated in Maryland [1]. In Canada, it is sensitive in Nunavut, British Columbia, Nova Scotia, and Newfoundland and Labrador, and it may be at risk in Prince Edward Island [2].

Anemone canadensis
Anemone canadensis is occasionally cultivated in gardens for its attractive foliage and relatively obvious flowers [3]. The plant spreads primarily by rhizomes and can form large, dense colonies [4,5]. Anemone canadensis is toxic and should not be eaten [3,4].

Anemone canadensis
This plant is pollinated primarily by solitary bees [3].

Tuesday, June 9, 2015

Seed Dispersal by Wind: Eastern Cottonwood - Populus deltoides - Cotonier

Populus deltoides (eastern cottonwood) is putting on a phenomenal show in Montreal. As one passerby commented on the Olmstead trail in the Mont Royal park, in Montreal it snows all winter, and then it snows in the summer:

Populus deltoides seeds flying in the wind in huge numbers
So what's the deal here?

I've mentioned seed dispersal by ants (myrmechory) a few times with respect to Sanguinaria canadensis, Trillium spp, Dicentra canadensis, and Dicentra cucullaria. But of course myrmechory is only one of many different strategies that plants have for dispersing their seeds. So today I'm going to talk a bit about anemochory (wind dispersal).

The general principle, of course, is that it is in the plant's best interest that its offspring are dispersed a reasonable distance away, so that it doesn't create offspring that compete with it for resources (generally speaking reproduction isn't adaptive if it involves shooting yourself in the foot).

So today I'm going to write a bit about wind seed dispersal.

But first, I'd like to introduce the star of the day, Populus deltoides (eastern poplar, eastern cottonwood, cottonwood). This tree is native eastern North America (US range map here, Canadian range map here) and has been introduced in British Columbia [1]. P. deltoides is listed as sensitive in Alberta [1]. It is indicated as a weedy species in some parts of the US [2].

This species is dioecious (any given individual is either male or female) and produces catkins (drooping cylinders of flowers) when it blooms [3].

Populus deltoides leaves
The lower bark is not smooth like the bark on the younger branches. Instead, it is deeply scored:

Populus deltoides bark (lower trunk)
The female catkins, once fertilized, produce a sort of egg-shaped fruit:

Populus deltoides fruit
And this brings us back to the whole matter of wind pollination. Inside these catkins there are tons of tiny little seeds, each of which is attached to a large number of lightweight filaments. These burst open in early summer to release the seeds:

Populus deltoides burst fruit
Wind can be a very effective means to ensure that seeds are dispersed far from the parent tree, particularly if they start high up and are in a windy place. Seeds that are wind-dispersed tend to be very small and lightweight. There are a variety of arrangements of filaments for the filamentous types. The one most familiar for most people is probably the umbrella sort of arrangement in the dandelion. P. deltoides seeds simply have a tuft of numerous filaments that attach to the seed. The seeds of Asclepias syriaca (milkweed) are also like this. There are also the samara types, which are also wind-dispersed but at shorter distances (they are heavier, but although they travel less distance due to increased weight, the larger seeds have more nutrients and so a greater chance of germination).

Populus deltoides burst fruit
It has been a great year for P. deltoides; the air is thick with seeds and the ground is just covered in places:

Populus deltoides seeds coating the ground
So if you get the chance, go take a stroll where you might find some poplars and look up. It's quite a lovely show right now!