Spring Forward

The flowers of late winter and early spring occupy places in our hearts well out of proportion to their size.

~Gertrude S. Wister

The change in our clocks this past weekend is one of the ways most of us know that spring is on the way in spite of the cold the past few weeks. Another are the first truly warm days like we are now having. But, for me, I know it is spring when I discover the first wildflowers of the season in our woods. One of the earliest is one of my favorites, the diminutive Spring Beauty, Claytonia virginica.

Spring Beauty

Spring Beauty (click photos to enlarge)

I saw this one yesterday afternoon, just barely poking its flower head above the leaf litter as I was walking through the yard. I immediately stopped and thought, it really is Spring! I got down on my hands and knees to take a closer look at the delicate beauty of the plants’ five petals. The petals can be quite variable, ranging in color from white to pink, but almost all have pinkish lines which appear to converge on the center of the flower. My flower has very faint lines, the so-called “bee guides”, which pollinators can see better than us. Research has shown that these lines on flower petals are used to guide the pollinators to the nectar when they visit a flower. A small ground-nesting bee collects the pollen from this plant and feeds it to its larvae. The aptly-named Spring Beauty Bee, and a few other species of small insects (especially a species of Bee Fly around here) are the primary pollinators.

Spring Beauty close up

And the pollen is quite noticeable on this species of flower – it is pink. You can see the pink pollen in the pollen baskets on the legs of the Spring Beauty Bee as it goes from plant to plant on warm, sunny days. The flowers tend to open mid-morning and close by late afternoon, and may remain closed all day on cloudy or rainy days. This helps preserve the pollen to increase the chances that a bee will visit on a sunny day and cross pollinate the plant.

Spring Beauty 2

Spring Beauty is one of the earliest of our spring wildflowers

In addition to the beauty and complexity of the flowers of Spring Beauty, it also has an edible small tuber which is quite tasty to us, and a variety of wildlife. It is a great small plant for your home garden as it is deer-resistant. It can add a splash of color to your woodland garden for a few weeks each spring, before the whole plant goes dormant. It then remains most of the year as only an underground tuber until you need another pick-me-up glimpse of a delicate spring flower after next year’s long winter. This tiny, often overlooked flower, is a perfect example of why we all need to become more aware of our native species and why we should try to plant local natives whenever possible. In today’s New York Times, there is a great op-ed by native plant guru, Doug Tallamy, on why natives are important, Take a look, it is a good read. Then get outside and learn more about native plants in your area, and consider planting some for yourself, and for your local wildlife.

 

 

 

 

 

Crossvine

I am a native plant promoter and have been for many years. While there is nothing wrong with planting ornamentals in the landscape (as long as they are not potential problematic invasives) I appreciate getting to know our native species and encouraging them in my landscape and in those of schools and other public areas where I work. A connection with native species is just one more way to help people become better stewards of our natural areas. And I have a particular fondness for spring blooming species like Crossvine, Bignonia capreolata.

Crossvine flowers on ground beneath vine

Crossvine flowers on ground beneath vine

I remember seeing my first Crossvine blossoms many years ago – lying on the ground, not hanging on the vine. I looked up and finally saw the vine with attached blooms way up in the top of an ash tree. This may be why this beautiful vine has not caught on more with homeowners – relatively few people see it in its glory because it often grows 50 feet or more into the canopy.

Crossvine planted on cedar snag

Crossvine planted on cedar snag

But if planted along a fence, trellis, or even a dead snag where we ground-dwellers can appreciate it, Crossvine can be spectacular. I once stuck a cedar snag in the ground and planted a variety of Crossvine that had more orange than most wild specimens and it provided a beautiful spray of flowers every April and early May.

Crossvine flower close-up

Crossvine flower close-up (click to enlarge)

The bloom time, color and shape of the flowers hint that Crossvine is a favorite of Ruby-throated Hummingbirds returning to their breeding grounds in the southeast. When a hungry hummer pokes its head and bill into the flower it is likely to touch the flower parts, which are clustered near the roof of the flower tube.

Flower showing pollination

Cut-away of Crossvine flower to show pollination

This transfers any pollen on the hummingbirds’ head to the pistil (female part) and dusts its forehead with new pollen from the anthers (male part of flower) as it exits and zips to the next Crossvine blossom. I have also watched bumblebees and a few swallowtails visit the blossoms. It is also a host plant for the Rustic Sphinx Moth, although I have never seen one feeding on it (yet).

Crossvine leaflet

Crossvine leaflet (click to enlarge)

Like its close relatives, Trumpet Creeper and Catalpa, the flowers of Crossvine produce long pods filled with flat, winged seeds that are wind-dispersed. It also spreads from root sprouts and can be found creeping along the ground in many places in the Piedmont and Coastal Plain, especially bottomland forests. The leaves are a bit unusual in that they are really leaflets divided into three parts – two shiny, semi-evergreen leaves, and between them, a leaflet that is modified into a coiling tendril, which allows the vine to cling to tree trunks, fences, and almost anything else it touches. The leaves are a dark green in summer and often turn purplish-green in winter before falling right before the new bright green spring growth appears.

Crossvine cross-section

Crossvine cross-section (click to enlarge)

While I think the leaf arrangement as the vine climbs up a tree trunk has a resemblance to a cross or a bent “X”, the plant is supposedly named for the cross pattern seen in the pith when you cut a cross section of the vine.

Crossvine flowers

Crossvine flowers on garden fence

Do yourself and your hummingbirds a favor and plant one of these beautiful native vines in your landscape this season and you can enjoy it for years to come.

Crested Dwarf Iris

Crested dwarf iris patch

Crested Dwarf Iris

I have always had a fondness for the wildflowers of spring woodlands and have planted them in shady spots as a harbinger of my favorite season. One of the hardiest of the spring ephemerals is Crested Dwarf Iris, Iris cristata.  I have purchased many of these (and other native wildflowers) over the years from the NC Botanical Garden (http://ncbg.unc.edu/) in Chapel Hill. They run an honor system plant sale from April through October and usually have a large sale event in September. I have also transplanted some from areas that were being developed by digging a few of the stubby rhizomes and planting them in shallow soil. It seems these tiny plants do best on rich wooded slopes, ravines, stream banks and other places where their rhizomes remain partially exposed and the beautiful sword-shaped leaves are not covered by deep leaf litter.  If you have typical garden varieties of iris you may do a double take when you first see this one – a tiny plant reaching only 3-5 inches in height. The flowers are usually some shade of blue or violet (occasionally white) and they tend to grow in patches, offering a visual delight to the spring woods walker.

Crested dwarf iris flower

Crested Dwarf Iris flower (click to enlarge)

They are named for the yellow crinkled crest on the sepals, which serves to guide pollinators (mainly bees) to the nectar deep within the throat of the flower (although I have also read it may give the bee something to grasp onto while navigating toward the nectar). If you look closely at an iris, you will notice it has an unusual flower structure. The three largest petal-like structures are actually sepals (which enclose and protect the flower bud before it opens). In iris flowers, they are also called the falls. The wide tip of the fall provides a place for pollinators to land.

Crested dwarf iris style arm

Crested Dwarf Iris style arm (click to enlarge)

Arching over each fall is a modified reproductive part called the style arm. This is probably the most unusual part of an iris flower. I had read about this but decided to take a closer look which required lying down and propping the flower parts open with a tiny twig to better view and photograph them (the things you have to do for science).

Dwarf Crested Iris flower parts

Dwarf Crested Iris flower parts

Just under the tip of the style arm is the stigma lip. This is the area that receives the pollen. It is a light-colored exposed curved edge just under the arch. A visiting bee must push under this style arm in order to access the nectar that is deep inside the throat of the flower. While crawling down toward the nectar glands, pollen is scraped off the back of the bee by this edge and attaches to the sticky stigmatic lip. The anthers (male, pollen-producing parts) are elongate structures behind the stigma lip. After the bee gets scraped of pollen, it then brushes up against the anther and gets fresh pollen. That pollen is unlikely to be transferred to this particular stigma lip as the bee backs out (they often exit through the gap in the arch). Bees are the primary pollinators as few other insects have the strength to push under the style arm.

Crested dwarf iris rhizomes

Crested Dwarf Iris rhizomes (click to enlarge)

The rest of the plant parts are a bit more the usual…the true petals (often called standards in iris) are the smaller of the colorful parts, and most often stand in a more upright position than the falls. Like in most flowers, they serve to attract pollinators. The rhizomes are short and chunky and connected to one another by slender runners. The sword-like leaves are attractive even when no flowers are present.

crested dwarf iris bud

Crested Dwarf Iris flower bud

One thing I noticed yesterday is how quickly the flower opens. Here is a picture of the flower bud on one iris at 10:37 a.m. yesterday. When I returned from some errands at 3:00 p.m., the flower was fully opened.

The modern name for the iris flower is believed to have originated in ancient Greece. There, the flower was associated with the goddess Iris, a divine messenger who traveled from heaven to earth on rainbows. Throughout history, iris have represented wisdom, faith, and courage and been used as a royal symbol of king and queens. While that glory most probably went to their larger cousins, the diminutive Crested Dwarf Iris also deserves recognition and appreciation as we wander the spring woods.