Month: May 2018

by

Field Trip: Hyatt Hidden Lakes Reserve

May is American Wetlands Month, which I have written about a few times here. The way we like to celebrate is to find a wetland nearby and spend a couple hours exploring and learning about the area. Luckily there is a wetland a few miles from our house. Hyatt Hidden Lakes Reserve is a 54 acre, city-owned wetland and nature reserve that is open to the public. It features a series of trails designed for nature viewing and recreation. Along the way there is a series of interpretative signs with lots of information about wetlands and the flora and fauna that call them home.

One cloudy Sunday morning, Sierra and I ventured out to our neighborhood wetland. What follows is a photo diary of a few of the things we saw while we were there.

The southwest corner of Hyatt Hidden Lakes Reserve

One of the coolest features of the reserve is this bat house called HaBATat.

Seed head of teasel (Dipsacus fullonum); behind it are a series of bird nests designed for various species of cavity nesters.

Common yarrow (Achillea millefolium) with a view of one of the ponds behind it.

We visited shortly after the cottonwoods (Populus spp.) had dropped their fluffy seeds.

Interpretive signage like this teach visitors about the various features and benefits of wetlands.

Walkways like this one allow for a closer view of the wetlands and feature additional interpretive signage.

Sierra spots something in the shrubbery.

Perhaps it was this yellow-headed blackbird.

Or maybe this male mallard.

One strange-looking, yellow-leaved branch among the willows (Salix sp.); Sierra and I wondered why.

Some wrinkly mushrooms that Sierra discovered.

We kept seeing this interesting insect on the flower heads of the grasses.

The butt of a bumblebee on the flowers of yellow sweet clover (Melilotus officinalis), captured by Sierra.

What wetlands did you visit this May? Let us know in the comment section below.

See Also: Field Trip: Bruneau Dunes State Park

Advertisement
by

Tiny Plants: Draba verna

Draba verna is a small but memorable plant. Common names for it include early whitlowgrass, vernal whitlowgrass, and spring whitlow-mustard. Sometimes it is simply referred to as spring draba. As these common names suggest, Draba verna flowers early in the spring. It is an annual plant that begins its life by germinating the previous fall. While its flowers are minuscule, multiple plants can be found packed into a single section of open ground, making their presence more obvious. This and the fact that it flowers so early, are what make it so memorable. After a cold, grey winter, our eyes are anxious for flowers, and even tiny ones can be enough.

Draba verna

Draba verna is in the mustard family (Brassicaceae), which is easy to determine by observing its flowers and fruits. The flowers are about 1/8 inch across, with four, deeply-lobed petals. The fruits are oblong, “football-shaped,” flattened capsules that are divided into two chambers and hold up to forty seeds or more. Flowers and fruits are borne at the tips of branched stems that are leafless, hairless, and very thin. Stems arise from a small rosette of narrow leaves that are green to purplish-red and slightly hairy. The plant itself is generally only an inch or two wide and a few inches tall, easily missed other than its aforementioned tendency to be found en masse.

flowers of Draba verna via eol.org

Draba verna occurs throughout much of eastern and western North America, but is said to be introduced from Eurasia. A few sources claim that it is native to North America, but as far as I can tell, that is unverified. Either way, it is naturalized across much of its present range, and even though many of us consider it a weed, it doesn’t seem to be causing too much concern. It’s too tiny and short-lived to really be a problem. It makes its home in disturbed and neglected sites – along roadsides; in fields, pastures, and garden beds; and in abandoned lots. The one place it may be trouble is in nurseries and greenhouses, where it might be able to compete with young plants in pots.

open capsule and seeds of Draba verna via eol.org

The flowers of Draba verna are self-fertile, but they are also visited by bees that have ventured out in early spring. The foliage might by browsed by rabbits and other small mammals, but otherwise this plant is of little use to other creatures. Being in the mustard family, it is likely edible, but again it is so small that harvesting it would hardly be worth it. Instead, maybe its best to leave it in place and enjoy it for what it is: a tiny, brave reminder that spring is on its way and an encouragement to get down low once in a while to admire the little things.

An attempt at sketching Draba verna fruits on a raceme.

See Also: Tiny Plants: Duckweeds

by

Spring Weeds in the Mustard Family

Is there a plant family that consists of more weedy species than the mustard family? Asteraceae and Poaceae, for sure. Fabaceae or Lamiaceae, perhaps. Regardless, Brassicaceae is replete with dozens of species – mostly annual – that are skilled at taking advantage of the disturbed environments that humans are in the habit of creating.

It helps that the mustard family is so large: 372 genera and over 4,000 species distributed across the globe. Around 55 genera are said to occur in North America. Most of the plants in this family are herbaceous; few are shrubs. Foliage is aromatic, especially when crushed. Flowers are particularly distinctive. Each flower has four petals – in some species petals are divided, giving the impression that there are more than four – arranged in the shape of a cross or “X.” Flowers are often small, have 4 tall stamens and 2 short stamens, and commonly come in white, yellow, pink, or purple. They are arranged on a raceme, which is typically either tall and straight or compact and flat-topped.

Fruits in the mustard family are capsules with two compartments separated by a clear membrane. The capsules may be at least three times longer than they are wide, in which case they are referred to as a silique; or they may be less than three times longer than they are wide and referred to as a silicle. This is a curious distinction, and it doesn’t tell you all that much. It’s more important to understand that the capsules of mustards can come in various sizes and shapes, and that some can be long and narrow while others are short and either round or angular.

mustard seeds via wikimedia commons

Despite the size or shape of the capsule, enclosed are numerous seeds – sometimes dozens. Surely one of the reasons why plants in the mustard family are so successful at proliferating is their ability to produce thousands, even tens of thousands, of seeds per plant. The seeds are typically tiny; and while they may not make it very far from the parent plant, they are numerous. Depending on the species, they can also remain viable for years, affording them the opportunity to sprout whenever conditions are right. You may have heard the biblical verse about faith the size of a mustard seed giving one the ability to move mountains. Size seems irrelevant here, so how about faith as tough, resilient, opportunistic, and resourceful as a mustard seed? If a mountain can be moved, mustards might be the one to do it.

While it isn’t the scope of this post, it’s worth mentioning the chemical compounds present in mustards that give them the flavors and health benefits we enjoy as well as the toxicity that can harm us and any other organisms that dare consume them. Glucosinolates, which are present in various concentrations depending on the species, are a defining characteristic of plants in the mustard family. They contribute to the spicy-ness of things like horseradish, radish, and condiment mustard while also acting as a natural insecticide, deterring herbivory.

And now on to the cast of characters:

Whitetop (Lepidium spp.)

Garlic mustard (Alliaria petiolata) – a noxious weed in many parts of North America – is fortunately not an issue in southwestern Idaho, otherwise it would be first on the list. Instead, we deal with whitetop – a noxious weed in Idaho and several other states. As the common name suggests, individual plants – up to two feet tall – are topped with a dense cluster of tiny, white flowers. Seed production in this group isn’t as abundant as other mustards; instead, the tour de force are their rhizomes. Whitetop is a perennial plant that spreads aggressively via underground stems as well as root fragments and can easily form expansive, dense patches, outcompeting other plants in the area.

Another common name for this group is hoary cress on account of their gray-green, fuzzy foliage. They are further distinguished by the shape of their seed pods: lens-podded hoary cress (L. chalepense), heart-podded hoary cress (L. draba), and globe-podded hoary cress (L. applelianum).

white top (Lepidium sp.)

white top (Lepidium sp.)

Tansymustard (Descurainia spp.)

There are two species of tansymustard (also known as flixweed) that occur in my part of the world, one is native and the other is introduced from Europe. They are indistinguishable to my untrained eye. If I have seen them side by side, I wouldn’t have known it. They are both annuals and can be as short as a few inches to over two feet tall. They have highly dissected, fern-like leaves and tiny, pale yellow or green-yellow flowers. The seed pods are very skinny and around an inch long. Each pod can hold 40 seeds, and a large plant can produce over 75,000 seeds. They are quick to take advantage of disturbed soil and come up in abundance after a fire. I’m not sure what it is about this year, but they have been particularly prolific this spring.

tansymustard (Descurainia sp.)

tansymustard (Descurainia sp.)

Blue Mustard (Chorispora tenella)

Also known as musk mustard or crossflower, this sticky, stinky, annual plant apparently makes cow’s milk taste funny; however some people still enjoy eating it. It can get to about a foot and a half tall, and is adorned with pretty, little, blue-purple flowers. The pointy seed pods split crosswise rather than lengthwise, an uncommon trait in mustards.

blue mustard (Chorispora tenella)

blue mustard (Chorispora tenella)

Desert Madwort (Alyssum desertorum)

Like tansymustard, this species is very similar in appearance to another closely related species, Alyssum alyssoides (commonly known as pale madwort or yellow alyssum). Both are annuals under a foot tall, covered in tiny hairs, with minuscule yellow flowers, and numerous round seed pods. They are adapted to dry, neglected sites.

yellow alyssum (Alyssum dessertorum)

Annual Honesty (Lunaria annua)

If you don’t recognize this plant when it’s flowering, you will when its seed pods ripen. They are thin, round discs up to three inches across. Eventually, the outer layers of the seed pods fall away, and translucent membranes remain, sometimes with seeds still attached. This trait has earned this species common names like money plant and silver dollar. The plants are attractive, reach up to three feet tall, and produce showy, purple flowers, which explains why they are popular ornamentals. However, like other mustards, the proficiency with which they reproduce in abundance via seeds, means they also easily migrate into natural areas and neglected sites.

annual honesty (Lunaria annua)

Hairy Bittercress (Cardamine hirsuta)

This little, quick-growing, fast-spreading annual is a common nuisance in greenhouses and nurseries. On stalks above compact rosettes are borne clusters of white flowers that, as Ken Thompson writes in The Book of Weeds, “are so tiny they are almost invisible.” The slender seed pods burst open at maturity, sending minuscule seeds flying. Brush your hand over a patch of mature hairy bittercress and you will be bombarded.

hairy bittercress (Cardamine hirsuta)

And the list goes on…

I’ve observed several other weedy species in this family recently, but to keep the length of this post reasonable I will just list them here: shepherd’s purse (Capsella bursa-pastoris), clasping pepperweed (Lepidium perfoliatum), spring draba (Draba verna), tumble mustard (Sisymbrium altissimum), and pennycress (Thlaspi arvense). This list only scratches the surface; there are many other weeds in the mustard family. All deserve to be mentioned, so perhaps another time.

See Also: In Defense of Plants – One Mustard, Many Flavors

by

The Creeping Charlies and Common Name Confusion

This is a guest post by John Tuttle.

———————

Most of us know creeping charlie as the all-too-often irritating weed which takes over our grassy lawns. This evergreen plant’s life cycle is year round. The garden-invading variety which sprouts little bluish-purple flowers has been given the title Glechoma hederacea (or sometimes Nepeta glechoma) via binomial nomenclature and is a member of the mint family, Lamiaceae. Additional common names for this creeping charlie include ground ivy, catsfoot, and field balm.

Travelers from Europe took the plant with them, distributing it throughout other parts of the globe, and it is now deemed an aggressive, invasive weed in various areas in North America. It has crenate leaves, and its size varies depending on its living conditions. It has two methods of reproduction. The first is made possible by offshoots called stolons (or runners), stems with the special function of generating roots and transforming into more plants. Thus, you will often find not an individual creeping charlie plant, but a whole patch, all of them connected via the runners. The other self-distribution method is simple: seeds.

creeping charlie (Glechoma hederacea) via John Tuttle

The creeper is edible, and if you were in a spot where you didn’t know when your next meal would be, this type of creeping charlie would probably be a welcome source of energy. Wild food educator, Karen Stephenson, suggests its use in simple dishes such as soups and omelets, but that’s probably for those who are cooking at home and not trying to fend for their lives in some forest. Starving in the woods is a bit of an extreme, but it has happened. Glechoma hederacea has also been used for making tea. It contains minerals like copper and iron, as well as a significant amount of vitamin C.

The weed also has a number of possible health benefits such as being a diuretic, anti-inflammatory, and antiviral. However, other researchers have cautioned people to be leery of consuming it as it has been known to be fatal to equines and bovines. It contains chemicals that can discomfit the gastrointestinal tract. It is further suggested that during pregnancy women should not intake any amount of any type of creeping charlie.

Up to this point you may have found the terms I’ve used, such as “this type of creeping charlie,” to be a little odd. In fact, the term creeping charlie does not refer to only a single species of creeper. It’s actually used for several.

Another plant hailed as “creeping charlie” is Pilea nummulariifolia of the family Urticaceae, a grouping otherwise known as the nettles. Pilea is the name of the genus of creeping plants; the artillery plant is also classified under this genus. Pilea nummularifolia is also known as Swedish ivy and is often grown as a houseplant. It is native to the West Indies and parts of South America. This viney plant flourishes when supplied with an ample amount of water.

creeping charlie (Pilea nummularifolia) via eol.org

Yet another plant commonly referred to as creeping charlie is Micromeria brownei, synonymously referred to as Clinopodium brownei. It is also used in some teas, but as mentioned above, pregnant women in particular should steer away from consuming it. Apart from the term creeping charlie, a few more common names for this plant include Browne’s savory and mint charlie. Like Glechoma hederacea, Browne’s savory is considered a mint. It produces flowers that are white with hints of purple on the petals and in the throat. This species is quite common in the state of Florida and in parts of Central America; although plants in this genus grow around the world.

Like Pilea nummularifolia, this species loves a good source of water. Its thirst for moisture is so strong, that it can actually adapt itself to an aquatic lifestyle, that is, one which occurs in water and not in dry soil. Many aquarists, people who enjoy keeping aquatic life, love this plant. It can also be trimmed with practically no damage to the plant. It is extremely durable and quite capable of adapting to different circumstances. For instance, Micromeria brownei can be situated midground inside a fish tank. The creeping charlie is perfectly at home totally submerged under water. If a plant floats to the surface then it should typically produce flowers. This adds a new dimension to some of the generic aquatic flora which is often used in many tank displays.

creeping charlie (Micromeria brownei syn. Clinopodium brownei) via wikimedia commons

There you have it. Three different types of plants that have different uses and dangers, and they are all called creeping charlie. Be advised when you’re talking about true creeping charlie – Glechoma hederacea: the invasive weed with the purple flower – that you remember to specify, because “creeping charlie” could mean one plant to you and some plant from an entirely different family to another.

———————

John Tuttle is a Catholic guy with a passion for the media and creativity. Everything about science and health interests him. He’s a writer for publications such as ZME Science and Towards Data Science. John has started his own blog as well called Of Intellect and Interest. He’s also a published ebook author and the 1st place winner of the youth category of the 2017 Skeena Wild Film Fest. You can follow him on Facebook here, and he can be reached anytime at jptuttleb9@gmail.com.

by

The Seed Salting Experiments of Charles Darwin

In the second chapter of his book, The Diversity of Life, Edward O. Wilson describes the massive volcano that sunk a large portion of the island Krakatau in the summer of 1883. Rakata, the remnant that remained, was now “a sterile island” covered in ash. But it didn’t remain sterile for long. This natural disaster offered biologists the opportunity to watch as a fragment of earth, suddenly stripped of life, turned green again.

Life returned pretty quickly, too. In less than 50 years, nearly 300 species of plants had recolonized the charred landscape. Much of this rebirth was thanks to “aeolian plankton” – tiny wind-borne lifeforms that Wilson describes as “a rain of planktonic bacteria, fungus spores, small seeds, insects, spiders, and other small creatures” that fall “continuously on most parts of the earth’s land surface.” The seeds of some plants likely floated or “rafted” over, and still others may have arrived in the stomachs of birds “to be deposited later in their feces.”

Wind, water, and wing. It is well-accepted today that these are natural means by which the seeds of plants make their way to remote islands. However, in Charles Darwin’s day, things were not so settled. Decades before we understood things like plate tectonics and continental drift, there was ongoing debate about how the flora and fauna residing on islands got there. Were there multiple creation events or were there a series of land bridges and continental extensions now sunken in the sea? Unconvinced of one and skeptical of the other, Darwin embarked on a series of experiments to determine the possibility of an alternate hypothesis: long-distance dispersal.

Darwin wasn’t completely opposed to the idea that some species may have reached remote islands by land bridges of some sort; however, as James T. Costa writes in Darwin’s Backyard, his “imagination [ran] wild with scenarios for long-distance transport by floods and currents, whirlwinds and hurricanes, dispersal by birds, rafting quadrupeds carrying seeds in their stomachs or adhering to their fur, floating trees with seeds wedged in root masses, insects with seeds or eggs stuck to their legs, icebergs, and more.” He was convinced, “improbable as it was that, aided by wing or wave, propagules from a mainland could make it to distant islands.” After all, the vastness of geological time allows for chance events despite how improbable they may be. Even more, such events are “testable.”

So test them, he did. Among a series of experiments regarding long-distance dispersal were Darwin’s extensive seed salting trials. He began by using common vegetable seeds: broccoli, cabbage, oats, radish, lettuce, flax, and many others. He placed seeds in small bottles containing 2-3 ounces of salt water. Some bottles were placed outside in the shade where the air temperature varied throughout the day; other bottles were kept in his cellar where the temperature was more stable. He also placed seeds in a tank of salt water made with melted snow. The water in some of the jars, particularly those with brassica and onion seeds, turned foul, and as Darwin writes, “smelt offensive to a quite surprising degree;” however, “neither the putridity of the water nor the changing temperature had any marked effect on their vitality.”

In fact, while a few did quite poorly, the majority of the seeds that Darwin tested germinated just fine after soaking in salt water. At least for a short period anyway. Germination rates tended to decrease dramatically the longer seeds were soaked. For example, “fresh seed of the wild cabbage from Tenby germinated excellently after 50 days, very well after 110 days, and two seeds out of some hundreds germinated after 133 days immersion.” Darwin found that capsicum (i.e. peppers) “endured the trial best, for 30 out of 56 seeds germinated well after 137 days immersion.”

The seeds and dried fruit of Capsicum annuum (via wikimidia commons)

Darwin’s seed salting experiments seemed to be going well until his friend and colleague, Joseph Hooker, pointed out that seeds often sink when placed in water. Darwin wondered if he had been “taking all this trouble in salting the ungrateful rascals for nothing.” Despite the setback, he began another series of tests to determine which seeds sink, which float, and how long they float before they ultimately sink. The results weren’t as bad as expected. A number of species floated for several days, including the seeds of asparagus which were found to float for about 23 days if the seeds were fresh and up to 86 days if they were dried. By his calculations then, ocean currents could carry asparagus seeds over 2800 miles.

While soaking seeds in salt water, Darwin was engaged in a number of other seed dispersal studies, some quite bizarre. In one, he attempted to get goldfish to take mouthfuls of seeds, the idea being that if a fish having recently swallowed seeds was eaten by a seabird which then deposited the undigested seeds on a distant island, those seeds could germinate and establish themselves in a new environment. Unfortunately, Darwin’s subjects wouldn’t oblige: “the fish ejected vehemently, and with disgust equal to my own, all the seeds from their mouths.”

Despite a few botched experiments, Darwin turned out to be correct – long-distance dispersal explains much of the geographical distribution of species. Those who favored ideas of sunken land-bridges and continental extensions weren’t altogether wrong either. Costa writes: “Ironically, there is a kernel of truth behind the old idea of continental extensionism: rearranged and sometime contiguous continents…explain the distribution of some groups. But chance long-distance dispersal has never gone away. Improbable and rare as such events are, they are far from mysterious, and certainly not miraculous.”

Want to carry out your own seed salting experiments?

Darwin’s Backyard by James T. Costa includes detailed instructions, along with instructions for Darwin’s duck feet experiment [Do ducks transport snails, seeds, or other things that get attached to their feet?] and many others. Darwin Correspondence Project is a great resource as well.