Some Rarities and Weedities

Blue Jay Barrens has never had an abundance of early spring wildflowers, and as the deer population increases, those that were here years ago have decreased in number. As a result, my perception of the early spring blooming season is that of a sprinkling of small white blooms. All come from tiny members of the mustard family. Some are quite rare, while others are prolific weeds. The first to show itself is generally Michaux’s Leavenworthia, Leavenworthia uniflora, a species that is listed as threatened in Ohio. I’ve been told that I feature this species, along with a couple of other similar subjects, far too often in this blog. Fortunately, the person providing that information is quite mistaken, so I will continue to discuss these plants at whatever times I deem appropriate.

The Leavenworthia is an annual plant and races along in its attempt to provide seeds for future generations. The blooms, held only a couple of inches above the soil surface, are hard enough to see. Add to that the rapidity with which the bloom withers around a quickly growing seed pod, and a person is lucky to catch a glimpse of these flowers at all.

The smallest of the early bloomers barely reaches an inch in height from the ground up to the top of the flower stalk. This is Carolina Whitlow-grass, Draba reptans, another state threatened species. Carolina Whitlow-grass is not a species that you will casually observe while out walking on an early spring day. You have to get down close to the ground and actively seek out these plants.  One identifying characteristic of this plant is the relatively smooth stalk supporting the cluster of flowers.

Prior to flowering, it’s best to have some type of magnification when trying to view the plant. At this stage, the plant always reminds me of a tiny cactus, but there’s no fear of being stuck by spines here.

Wedge-leaved Whitlow-grass, Draba cuneifolia, is the third early spring rarity that I regularly see. The leaves of this species have shallow pointed lobes along the margins, but this leaf feature may not be noticeable in very small plants.  The surest way to separate Wedge-leaved Whitlow-grass from the preceding the species is by comparing the flower stalks. The flower stock here is densely hairy.

Wedge-leaved Whitlow-grass has the typical four petaled flower of the mustard family. Each petal has a shallow indentation at the tip.

Several non-native species add their bits of whiteness to the spring blooming season. These are weedy species that are commonly found in most lawns and gardens. Whitlow Grass, Draba verna, although related to our native rarities, is an extremely common non-native weedy plant. One reason that these plants are so successful in human disturbed habitats is the fact that they flower and distribute their seed before most people become active with their gardening and weeding activities. The seed from these plants sits quietly in the soil through the summer and fall months, and is ready to spring forth the following winter.

The four petals of the Whitlow Grass are so deeply split down the center that they are often mistaken as having eight petals. This feature quickly distinguishes these alien plants from our native species.

Becoming ever more common in the urban landscape is the Hairy Bittercress, Cardamine hirsuta.  Blooms of this plant quickly disappear in favor of elongated pods that rapidly fill with ripe seed.  Once the seed is mature, the pods will violently open at the slightest touch and scatter seeds in a wide area around the plant.  The seeds are easily carried away on people’s shoes and gardening tools, to colonize fresh areas.

Field Pennycress, Thlaspi arvense, is a non-native quick to invade into bare or disturbed ground. In most situations it forms thick patches of plants.

The Field Pennycress seedpods seem to develop as quickly as the flowers can form. In just a few days a tall spike of developing seedpods replaces the initial flower cluster. These non-native species are interesting, but my goal is to manage for native populations and that generally means that the non-natives are considered weeds and must go.

April Winter Annuals

My artificial barrens in a pot continues to evolve.  Originally planted in the container were Draba cuneifolia, Draba reptans, and Leavenworthia uniflora.  Draba reptans persists in small numbers and is hardly noticeable.  Draba cuneifolia and Leavenworthia uniflora aggressively compete for dominance of the container.  Since its creation, no two seasons in this container have been the same.

In 2013, Leavenworthia uniflora dominated the container.  Last year there was a fairly even mix of Draba cuneifolia and Leavenworthia.  This year the Draba cuneifolia is definitely in control.  Draba flower stalks form a miniature forest.

A loose cluster of flowers forms atop the stalk.  These plants are just beginning to bloom.  The flower spike will continue to enlarge and the immature buds seen in the center of the cluster will be brought into position to open.

A number of these small bees were busy visiting the Draba flowers.

Wild Draba cuneifolia plants are also doing well this year.

It’s unusual for the plants on the barrens to grow this large.  I’m certain that their growth patterns are influenced by weather conditions, but I don’t know if it was spending several weeks buried by snow or the excessive rainfall during the last six weeks or some other factor that is responsible for the impressive growth this year.

Draba reptans is also performing above expectations this year.  This plant toppled over, but that won’t stop it from producing a good crop of seeds.  Total height, or length, of this plant is not much over an inch, so it didn’t have far to topple.

Draba reptans is similar in appearance, but smaller than Draba cuneifolia.  One characteristic that separates the two is the hairiness of the flower stalk.  The stalk on reptans is practically hairless, while the cuneifolia stalk has a fuzzy hairiness along its entire length.

Drabas and Leavenworthias are blooming side-by-side in the container barrens.  Draba cuneifiolia has a shallow indentation at the end of each of the four petals.  Leavenworthia petals are all well rounded.  A couple of non-native Draba verna have also managed to invade the container.  Seen in the lower right of the photo, Draba verna petals are split almost in two, so the flower appears to have eight petals instead of four.

This year’s Leavenworthia plants are quite tiny and have only a single flower stalk.  I’m afraid they couldn’t compete with the rapid early growth of the Drabas.

Contrary to what I’ve noticed in past years, the Leavenworthia growing on the barrens are much more robust than those in the container.

Most of the barrens grown specimens are producing multiple flower stalks.  The seed produced from these should be a definite boost to future generations.

The Draba cuneifolia in the container are going to make a tremendous amount of seed.  I’ll collect as much as I can and scatter it out on the same barrens from which I originally gathered the seed for this container collection.  If my original removal of seed from the barrens resulted in a diminished population of Draba, I’m sure my replacement of seed has more than made up for the loss.

The container plants are producing so much seed that I’m now finding Draba cuneifolia growing in the cracks of the concrete apron outside my barn door.  I love it when a rare plant begins to behave like a weed.

Winter Annuals - Pot vs. Barrens Grown

The rains have come and temperatures have warmed.  That means the little winter annuals of the barrens are growing rapidly in order to gather sunlight and produce a crop of seed.  This must be done before neighboring plants grow tall enough to block the source of light.  The plants of my container bound barrens show change on an almost daily basis.  Blooms are not too far in the future.

 

The Draba cuneifolia that made such exceptional growth early in the season have developed a central stem and numerous side branches.  Below freezing temperatures during a period of no snow cover caused one plant to die and several others to develop dead areas on the leaf tips.  That bit of adversity hasn’t slowed these plants down any.  If our County Fair had a Draba category, I think this plant would be a sure winner.

Flower buds crowd the tip of the main stalk.  This cluster of buds alone will produce an amount of seed equal to at least a dozen normal sized plants.  Add to that the seed that will come from the flowers developing at the ends of the many branches and this plant will produce as much seed as 40 or 50 normal plants.   The total amount of seed from this one plant may exceed the total of all the plants growing in one of the barrens openings found at Blue Jay Barrens.

This is more typical of the container grown Draba cuneifolia plants.  I would expect this plant to produce two or three flower stalks.

Although I try to reproduce the barrens ecosystem in my containers, the true barrens provide much harsher growing conditions.  You won’t find any super sized Drabas growing out here.

This Draba cuneifolia is typical of the maximum sized plants found growing in the barrens.  It is just slightly smaller than the average pot grown specimen and will produce one or two flower stalks.  Fortunately, each flower produces an abundance of almost dust sized seed, so chances are good that some seed will survive to produce plants next year.

Container grown Leavenworthia uniflora is an impressive sight.  Leavenworthia produces no elongated stem.  The leaves radiate out from a central base in the same manner as the common dandelion.  Several pairs of short, pointed leaflets line the leaf stalk which terminates in a flat, roughly five lobed leaflet. 

Flower stalks emerge from the center of the plant at the base of the leaves.  Each stalk will bear a single flower which produces about a dozen seeds.  A plant of this size will produce ten or more flowers.

The barrens grown plants are noticeably smaller.  This plant was so small that the leaf stalk never got long enough to produce leaflets.  This small leaf cluster is capable of supporting only one or two flowers.  A single flower stalk is seen here, but it is early enough for the plant to produce a second if conditions remain favorable.  Annuals have only one chance to produce seed, so every bit of the plant’s energy goes into the effort.

Draba reptans is the smallest of the Drabas.  It could easily take 40 of these plants to equal the leaf area of one average sized Draba cuneifolia.  Most of those rocks seen in the photo are actually sand sized.

The Draba reptans that I find in the barrens are about equal in size to those grown in pots.  One reason for this may be the fact that I have a tough time actually spotting any plants smaller than this.  If I crawled around with a magnifying lens, I may find some of those extra tiny plants.  There’s no question that a lot can be learned about a plant by growing it in a container, but you can’t always apply that knowledge to field situations.

Plants 2013 - Barrens in a Pot

Most of my pot grown native plants were freed to live their lives in likely locations close to the house.  A few of the rarer collections were maintained.  This container mimics gravelly barrens conditions and houses a mix of winter annuals found naturally in the poor, dry soils of the barrens.  This plant community has successfully maintained itself for several years.

Leavenworthia uniflora has always been the star performer and 2013 was no exception.  The potted plants display a vigor far superior to that of the wild specimens.  I’ve learned a lot about these plants by having them in a situation that allows daily viewing, but I would still like to create a situation that more closely matches that experienced by the wild plants.

 

In March the Leavenworthia have created a tight cluster of flower buds in the center of the plant.  Wild plants typically develop three or fewer buds.

 

By April, a long stalk has pushed high above the leaves where a single four petalled flower blooms.

 

The flower is short lived and quickly gives way to a developing seed capsule.  This forest of stalks produces enough seed to repopulate the pot as well as for me to collect a good quantity which I return to the site at which I originally obtained seed for this project.

 

Also doing well in the pot is Draba cuneifolia.  The Draba is typically a little behind the Leavenworthia in development.  Buds are evident in early April.

 

Flowers open a week later.

 

Long stalks grow rapidly up through any competing vegetation so that the flowers are in the open and easily visited by small flies and bees.

 

Draba cuneifolia normally begins growth in early fall and overwinters as a tiny, few leaved plant tucked in close to the soil.  I was surprised in September 2013 when the Draba reached a growth stage equivalent to what is normally seen in early March.

 

By mid-January, after enduring long periods of sub-zero temperatures and weeks of snow cover the developmentally advanced plants were doing wonderfully.  These super plants were larger than any I had ever had in the pot.  The plant up against the pot wall to the far right is the one shown in the previous photo.  It has put on a lot of growth since September.

I’m not claiming to have produced a race of giants.  These individuals are well within the accepted size range for Draba cuneifolia.  I’m just pointing out that the wild grown Blue Jay Barrens representatives of this species do not come close to expressing their full genetic potential.  The wild plants remain small because that’s the best they can do under the conditions found in those areas in which they can survive.  Improvement in growing conditions would probably favor competing vegetation, so instead of the Drabas growing larger, they would probably be crowded out.

 

Here are the current conditions in the barrens pot.  Draba cuneifolia is presently the most developed species in the mix.  Leavenworthia uniflora is present in good numbers and there is a sprinkling of the diminutive Draba reptans.  It’ll be interesting to see how things progress this spring.

Winter Annuals on the Barrens

I’m not sure that there is any single event that indicates to me that we’ve made the transition from winter into spring.  If forced to choose, I could easily imagine the opening of the first of the year Leavenworthia uniflora bloom to be the pivotal point between the two seasons.  These tiny winter annuals are the first of the barren plants to put forth a bloom. 

It’s easy to miss the blooming of the Leavenworthia.  The plant grows in areas of rocky, bare ground and doesn’t get tall enough to make itself noticeable.  To see a Leavenworthia, you probably have to be looking for one.

Leavenworthia can not push themselves up through a thick vegetative mat. They stick to the open areas and do their growing before any other plants are active enough to give them any competition.  Lack of bare ground would mean the end of these plants.

A few dead grass stalks or dried grass leaves don’t slow the plants progress, but a thick layer would have eliminated these plants.  The grass just makes it that much harder to see the plants.  A search for Leavenworthia usually requires the eyes to be close to the ground.

The four petaled flower of the Leavenworthia uniflora, typical of the mustard family to which it belongs, is a signal to me that a period of rapid change is about to begin.  During the next few weeks, all manner of plants and animals will become active.  In all of the excitement, the Leavenworthia will quietly ripen and spread its seed.  Then it will disappear as it is hidden by the real show-stoppers of the barren plant community.

Growing along in the same area are the Drabas, even smaller mustards that are dwarfed by the Leavenworthia.  A single Leavenworthia could easily cover a dozen Drabas and a quarter could cover the averaged sized Leavenworthia.  They are a little bit later to bloom, but their seeds generally ripen at the same time as their larger neighbors.

An examination of these plants is well worth the price of dirty knees.  They won’t be around for very long.  I spend considerable time each year seeking out and enjoying these species.