Tag Archives: Invasives

Invasive Plant Profile: Artemisia vulgaris, Common wormwood, Mugwort

Posted on by
1

Artemisia vulgaris, Mugwort, in the sunny border at Garden #4 in Flatbush, Brooklyn, New York. The first photo shows the habit of growth. For scale, the stepping stones are 11″ square. The plants in this photo are about two to two-and-a-half feet tall.
The second photo shows an entire plant removed from this area. You can see the horizontal root below and to the right. The plant regenerates if any part of this root remains in the soil.
After taking these photos I removed all the plants.
Photos taken: June 4, 2006.

This photo shows what you get less than 20 days later if you don’t get all the roots out!
Photo taken: June 23, 2006

Artemisia Vulgaris, Common wormwood or Mugwort, is a perennial herbaceous (at least in Zone 7a) plant in the Asteraceae (Compositae), the Aster, Daisy or Sunflower family.

The emerging foliage, as seen in the third photo above, looks like Chrysanthemum. The maturing plants, as in the first two photos, remind me of ragweed. The pleasant (to me), pungent scent of the leaves alone identifies it as an Artemisia, a sage. The semi-woody stems and distinctive scent distinguish it from Chrysanthemum or ragweed.

The flowers individually are insigificant. When in bloom, collectively the flowers don’t offer much either, forming just a greyness around the tops of the plants, as if they had lint stuck between their leaves. I’ve seen some listings of more ornamental selections with more prominent flowers, and even one with variegated leaves.

“Wort” is an old suffix for plants traditionally used for medicinal and healing purposes, for example: Lungwort. I don’t know what “Mug” identifies that would need healing. It also has culinary uses as a seasoning. It’s widely available commercially, sold as an herb. You’re welcome to have mine for free, if there’s any left after I’m done ripping it out. Artemisias also have toxic properties. Among other applications, A. vulgaris has been used as a natural abortifacient in early pregnancy. Another well-known member of the genus is A. absinthium, Absinthe.

It has escaped cultivation and is reproducing in the wild. Several sources categorize it as invasive. Once established, it can be difficult to eliminate through mechanical means. It’s common along roadsides in New York City. The photos from my garden above show the long, rambling root system, and how easily it regrows from any small part of the root left behind. I expect to be pulling this up for years from my garden, until I’ve exhausted it.

References:

Technorati tags: ,

Insect Profile: Apion (Rhopalapion) longirostre, Hollyhock weevil

Posted on by
5

Apion (Rhopalapion) longirostre, Hollyhock weevil, on, of all things, my hollyhocks in the sunny border at Garden #4 in Flatbush. The upper photo shows a single male, I believe, on a leaf. The lower photo shows a pair in their typical posture, ie: mating. The female has her (even longer) snout buried in the flower bud.
Photos taken: June 4, 2006

The taxonomy of Apion (Rhopalapion) longirostre, common name Hollyhock weevil or (sometimes) Black vine weevil, is confusing. I’ve seen it listed as being in the Family Brentidae, the straight snout weevils, the Apionidae or Apioninae, and the Curculionidae. Whatever! They are in the order Coleoptera, the beetles.

The genus Apion seem to generally have long snouts. Their antenna are jointed and located halfway along the snout. A. longirostre is distinguished from other Apion species by its orange legs.

Their native range of A. longirostre is in Eurasia, originally limited to southern and southeastern Europe and Asia Minor. It has since spread much further afield there. It was first detected in North America in Georgia in 1914. Within fifty years it had spread across the continent.


They deposit their eggs in the ovaries of unopened hollyhock buds. The eggs hatch and the larvae develop within the ovary, eating the seeds. Within the still unopened bud, they pupate and emerge as fully-formed adults, chewing a hole from the inside out. Adults can winter over in the soil. They may also spread via hollyhock seeds.

This is my first encounter with this creature. I didn’t notice them during the first year in this garden, though they were probably already present. The adults are easily spooked. They move constantly. When I approached them with my macro lens, they would hide deep in the buds and under leaves. The photos above were the only two good ones – ie: in focus on the weevils, not the plant – I got out of the series. Oh, and did I mention they mate constantly?

From what I can find out, they seem to be host-specific: they don’t affect any other plants. Many, if not all Apion seem to be host-specific. A. fuscirostre, the Scotch broom seed weevil has even been intentionally introduced as a biological control for Spartium scoparium, Scotch broom. (Other weevil species are serious problems). There also doesn’t seem to be any biological controls for them, whether insect, fungus or what have you. It’s possible that some generalizing insect predator might be effective. All the literature suggests various insecticides, which I refuse to use. I’d rather just not be able to grow hollyhocks, if it comes to that.

Mechanical controls would seem to be the only option. They also tend to drop to the ground when disturbed, so that could be used against them by shaking them out onto some paper or other collector placed under the plant. I had been wondering why some of the hollyhock buds turned brown and papery before they bloomed. Weevils may be why. If so, then removing and destroying the unopened buds may also help control their population. I’ve also seen suggestions to either freeze the seedpods to kill the larvae (which would not affect overwintering adults), or open the seedpods and place them in the sun to drive out the weevils (my weevils were in full sun, so I don’t think that would bother them enough to make a difference).

Note that there is another weevil, Otiorhynchus sulcatus, which also goes by the common name of Black vine weevil. It looks completely different. In particular, it does not have the long snout with antenna; it looks more like a regular beetle. It’s behavior is also different. It does not lay eggs in flower buds; instead, they drop to the ground. Also, it feeds on multiple host plants. It’s much more of a problem than Apion.

http://bit.ly/7ZGBV7

Links

Tags:

First parrot sighting of the season!

Posted on by
Reply

I just heard, and then saw, a pair of the Brooklyn Parrots. This is my first sighting this season. They were flying down the adjacent road, just below rooftop level. I saw them as they passed between our two back neighbors’ houses. They’re easily identified. They are large (about the size of a blue jay), bright green, loud birds. Their flight is also distinctive: straight, strong, and fast.

Myiopsitta monachus, Monk Parakeets, have established numerous colonies in Brooklyn. They are Brooklyn’s most charismatic potentially invasive species. They are also now established in over a dozen other states.

Monk Parakeets are the only parrot species which build their own nests, rather than nest in existing cavities. They create large, communal nests of twigs and other materials. This is one of the characteristics which enables them to adapt to our winters. That, and they like to build their nests around the transformers of power distribution towers.

Links (in alphabetical order by title):

Invasive Plant Profile: Chelidonium majus, Celandine, Greater Celandine

Posted on by
1

Revised 2015-02-23: This was one of my earliest blog posts, first published in June 2006. I’ve overhauled it to 1) meet my current technical standards, and 2) improve the content based on the latest available information.


Chelidonium majus, Celandine or Greater Celandine, is a biennial (blooming the second year) herbaceous plant in the Papaveraceae, the Poppy family. It is native to Eurasia. It’s the only species in the genus.

It’s invasive outside its native range, and widespread across eastern North America. It emerges early in the Spring, before our native wildflowers emerge, and grows quickly to about 2 feet. That’s one of the clues to identification. It’s also one of the reasons why it’s so disruptive. The rapid early growth crowds and shades out native Spring ephemerals.

Greater celandine is one of the first weeds I identified when we bought our home in 2005 and I started the current gardens. Here’s my collection of photos from the garden’s second year, in 2006, highlighting the characteristics that help to identify this plant. The photos (click for embiggerization) show:

  1. Full view of plants, showing growth habit, bloom, and ripening seedpods on the same plants. The plants in this picture are about two feet tall. In the middle and lower left of the picture, you can see the leaves of Hemerocallis (Daylilies) just peeking out from under the Chelidonium.
  2. Broken stem with orange sap. You can also see a small flower bud in the leaf axil to the left.
  3. Detail of flower. Notice the 4 petals, clustered stamens, and central pistil with white stigma.
  4. Detail of ripening seedpod. These seedpods are what made me think at first that this plant was in the Brassicaceae (or, if you’re old-school like me, the Cruciferae), the Mustard family. It’s actually in the Papaveraceae (Poppy family).

At the time these pictures were taken in early June, these plants had already been blooming for two months. After I took these pictures, I removed all the plants (and there were many more than are visible in these photos!).

Part of coming to any new garden is learning the weeds. There are always new ones I’ve never encountered before, or that I recognize but am not familiar with. Learning what they are, how invasive or weedy they are, their lifecycle, how they propagate, and so on helps me prioritize their removal and monitor for their return.

For example, Chelidonium is a biennial. So pulling up visible plants before their seeds ripen and disperse kills this year’s generation and the generation two years from now. I might overlook next year’s generation this spring, but I’ll get them next year. The plants are shallowly rooted. By grabbing the plant at the base of the leaves, I can remove the whole thing easily, roots and all.

Chelidonium‘s seeds are dispersed by ants. They’re likely to show up next year close to where they were this year, but not necessarily in the same place. In addition, the soil probably has a reservoir of seeds from the years the garden was neglected. If I disturb the soil, or transplant plants from one part of the yard to another, they could show up in new places. By pulling the plants when they emerge in the spring, and keeping an eye out for their emergence in new places in the garden, I can easily control them. It will take a few years of vigilant weeding to eliminate them completely.

Note that, at a quick glance, this plant can be confused with the native* wildflower Stylophorum diphyllum, celandine-poppy. They’re very similar. Both are in the Papaveraceae, bloom in the spring with four-petaled yellow flowers, have lobed foliage and bright orange/yellow sap, and are about the same height. I find the seedpods the easiest way to distinguish them. The flowers of Stylophorum lack the prominent tall central pistil of Chelidonium, and the stamens form more of a “boss” around the center of the flower, not so obviously grouped in four clusters.

Stylophorum diphyllum, celandine-poppy, blooming and showing the distinctive, more poppy-like, ripening seedpods, in my urban backyard native plant garden, May 2013.

* Stylophorum isn’t native, or present, in New York. But it is native to eastern North America.

Related Content

Flickr photo sets:

References

Article, Fall 2005: The Changing Flora of the New York Metropolitan Region

Posted on by
Reply

The authors compare past distribution data from historical records, and current data from Brooklyn Botanic Garden’s New York Metropolitan Flora Project to determine changes in distribution over the past century. They further compare these changes between native and introduced species within the same genus, such as Celastrus scandens, American bittersweet (native) and Celastrus orbiculata (or C. orbiculata), Oriental bittersweet (introduced, and invasive), or Lonicera sempervirens, Trumpet honeysuckle (native) and Lonicera japonica, Japanese honeysuckle (introduced, and invasive).

We statistically analyzed 100 years of herbarium specimen data for woody plants in the New York metropolitan region in order to measure the floristic changes of this area. Change Index values were computed for 224 of the region’s 556 woody species to provide a specific measure of whether these species are expanding, contracting, or stable. The results show that, in general, nonnative invasive species are spreading rapidly in the region, while native species are in slight decline.
– The Changing Flora of the New York Metropolitan Region

Links

The Changing Flora of the New York Metropolitan Region, Urban Habitats, Volume 3, Number 1, Fall 2005, Brooklyn Botanic Garden, 1000 Washington Avenue, Brooklyn, NY 11225

GAO Report, April 24, 2006: Invasive Forest Pests

Posted on by
Reply

GAO just released a report on the status of efforts to eradicate Anoplophora glabripennis, the Asian longhorned beetle, or “ALB” for short:

Invasive forest pests have seriously harmed our environment and imposed significant costs upon our economy. The U.S. Department of Agriculture (USDA) is the lead agency for responding to forest pests. This report evaluates the federal response to three invasive forest pests–the Asian longhorned beetle [Anoplophora glabripennis], the emerald ash borer, and the pathogen Phytophthora ramorum (P. ramorum) [Sudden Oak Death]. Specifically, GAO describes (1) the status of efforts to eradicate these species, (2) the factors affecting the success of those efforts, (3) overall forest health monitoring programs, (4) coordination and communication of the three pest response efforts, and (5) USDA’s use of panels of scientific experts to aid in the response efforts.

Invasive Forest Pests: Lessons Learned from Three Recent Infestations May Aid in Managing Future Efforts, GAO-06-353, April 21, 2006
http://www.gao.gov/docsearch/abstract.php?rptno=GAO-06-353

In August 1996, the first ALB in the United States was discoved in Greenpoint, Brooklyn. I garden just a few blocks south of Prospect Park and the NYC ALB quarantine zone. To learn how to identify ALB, and NYC’s efforts, visit the NYC Parks ALB Home Page.

Web Resource: Invasive Species Weblog

Posted on by
Reply

Long-running, encyclopedic web log, with global coverage of invasive plants and animals:

… I started the ISW in April of 2002, with two goals in mind: 1) Find a way to keep up with current events and 2) Find a way to keep up with current internet trends. With a public record of my efforts, I have found that I am less likely to “slack off” and stop keeping an eye out for important invasive species issues.
As of January 2004, the ISW has over 600 entries, covering a full range of topics, from legal issues, to early detection warnings, to the use of invasive species in marketable products. …
Jennifer Forman Orth, “About the Invasive Species Weblog”, http://www.knottybits.com/isw/AboutTheISW.html

Ithaca, NY, May 22, 2006: Invasive Plants Threaten Six Mile Creek Banks

Posted on by
Reply

An article from The Ithaca Journal on an event which highlighted the threat invasive plant species pose to a local natural site.

The Ithaca Journal – www.theithacajournal.com – Ithaca, NY:

…
While there are some native plant species that can become invasive, most invasives hail from elsewhere, according to Bernd Blossey, an associate professor in Cornell’s Department of Natural Resources.

Blossey said he considers an “invasive” plant species any that can eventually overtake the native ones, becoming the dominant species in an area. In other words, not all non-native plant species are considered invasive, unless they start overtaking the ecosystem.

He also said the best way to protect against invasive plants is to detect them early to prevent them from spreading.
…