Those amazing and confusing Spring flowers
Flowers are of course some of the most beautiful objects within Nature's realm and they can be considered at a number of emotional and intellectual levels. If one thinks simply of the amazing variations in color and form, flowers can be perceived purely in terms of these aspects without any thought given to how or why they may look like this. There is nothing wrong with this "child-like" appreciation of flowers or nature in general, although it usually leads to a gradual accumulation of knowledge about natural patterns that are observed, and thus a more intellectual approach that involves some directed study. You might argue that asking questions about flowers might diminish their wonder, but I think it is actually the opposite. The more one learns about natural objects, the more fascinating and remarkable they become.
For example in walking around our farm in this glorious Spring-time I am struck by the diversity in form and color of flowers and what this might mean to their function. To take just three examples which are in bloom at this moment in early May, consider the "flowers" of the Fraser magnolia, the cranberry viburnum, and the ox-eye daisy (see attached photos). I put "flowers" in quotes to indicate that these flowers differ considerably in their structure. The magnolia is a very large single flower. The viburnum contains a group of flowers which are not equal- the large white flowers around the edge are sterile and are apparently designed to attract insects to the small fertile hermaphroditic flowers in the center. The familiar daisy (a composite) is a complex group of a large number of flowers which are specialized to produce either ray/petal or disc flowers; but the overall effect is that one is observing a single flower! You can see how these could represent an evolutionary sequence from the more primitive (magnolia) to the more advanced (daisy).
So what is a flower? It is simply a reproductive structure whose sole function is to propagate the species. The wonder lies in the incredibly complex forms and variations in patterns of growth, pollination and seed dispersal. Does the exhilarating riot of color and form exist only because of the eyes of insects and birds with color vision who will pollinate the flowers and disperse the seeds? Probably so, but we can consider ourselves fortunate that we are descended from primates with color vision who needed to be able to distinguish between ripe and green fruits and to distinguish leaf color.
Bill Dunson
Galax, VA & Englewood, FL
Comparing Across Landscapes...the Spicebush Budburst
Will someone up in the Blue Ridge check for me? What is the stage of blossom development on the spicebush in your area?..and what is the aspect and elevation of the shrub you observed? For a low elevation comparison check (and a glimpse into your future) with the flowering stage of the spicebush here in Charlottesville: click here...
A spicebush in Wildwood park today (taken by the Kesslers):
Jack or Jill in the pulpit?
A brief and comforting glimpse into our snowless future, from Bill Dunson:
I imagine most of you are familiar with the Jack-in-the-pulpit which is a not uncommon wildflower in wet woods of eastern North America. However I doubt if any of you have encountered this interesting member of the arum family on Feb. 7 in bloom as I did today at Lemon Bay Park in Sarasota County, FL. Taylor lists it as missing from Sarasota County which indicates how special this fresh water swamp is on the shore of Lemon Bay.
The pulpit or spathe surrounds the spadix (Jack and/or Jill - let us not be male chauvinists!) which holds the flowers. They are fertilized by flies attracted to the odor and heat of the flowers. Remember that their cousin skunk cabbage (also an arum) has a similar means of attracting pollinators. Young plants tend to have all male flowers; there are more female flowers as they age. Indeed some studies have shown that the predominant sex of the flowers is determined by the condition of the plant. If it has been a good year and the plant is healthy and has a good supply of nutrients in its bulb, it becomes female. In a bad year it produces male flowers. Why do you suppose this could be a good strategy for reproduction? Consider that it is "cheaper" to be a male and produce a lot of pollen to fertilize other plants. Producing fruits with seeds is a lot more expensive in terms of energy and a poor year could result in very few prospects for reproduction in female mode.
Pulpits (Indian turnip) can be eaten if properly prepared, but contain calcium oxalate crystals and other toxins that are poisonous. Fruits are bright red and are presumably eaten by birds and dispersed.
So watch out for the marvelous if somewhat sexually confusing Jack/Jill in the Pulpit in early Spring in your area.
Bill Dunson
Englewood, FL & Galax, VA
And a follow-up story from Bill:
On a second visit to my pulpit site in a freshwater swamp I noticed a difference in the distribution of male and female plants. There seemed to be a correlation between sunlight forest canopy gaps (mostly red bays here as an over-story) and the presence of more large, female plants (which have two leaves). The male-flowering plants only have one leaf and thus fewer resources available. I also opened the bottom of the spathe to see the actual flowers clustered at the base of the spadix (see photos). There is quite a difference in appearance of the two kinds of flowers.
Pulpits seem to be a common member of the early-blooming wildflower community so look for them in damp areas (boggy spots or north-facing wooded slopes) along with May-apples in your area. Note that May-apples have a similar resource-based flowering in that only plants with two leaves will flower. A similar phenomenon occurs with ginseng in that a minimum number of leaves is necessary for flower and fruit production.
Bill Dunson
Snake plant flowers
It is hard to believe that anyone has not at some time had snake plants (Sansevieria) in their family households. The ability of this interesting but strange plant to survive almost any treatment made it popular around the world as a house plant. Unfortunately in warmer areas such as Florida they ended up planted outside and have caused considerable problems since they are highly invasive, especially in shaded forest locations where native plants are crowded out by the snake plant. Removing them is problematic since the roots break into small pieces and generate many new plants.
I have fought a running battle with snake plants in our Florida yard since a former owner got them started. So I always considered them a big pest with no redeeming qualities. However I have now recognized that the regular Winter-time blooms of these plants are actually quite interesting from an ecological perspective (see photo). A spike of white tubular flowers emits a powerful fragrance and is actually quite beautiful, if you can get past the bad-boy image of this species. I am always interested in predicting what might pollinate specific flowers, based on flower color, shape and smell. I found out that this plant originated most likely from Western Africa but have not yet found out what pollinates it in its native habitat. However the white tubular flowers with a strong odor indicate pollination by a night-flying moth with a long tongue, possibly a sphinx/hawk moth whose larvae are often called horn worms.
I did find one article that determined that the primary sugar in the nectar of the common snake plant is sucrose, and predicted that this in conjunction with the flower structure would attract mainly sphinx moths. Note also that the authors found extra-floral sources of nectar and surmised these might satisfy creatures such as ants that might otherwise steal the flower nectar and limit the plant's ability to reproduce:
http://aob.oxfordjournals.org/cgi/content/abstract/58/4/541
So look around you with a renewed interest in plants and animals that you might have dismissed as unworthy of notice, and you may find unsuspected beauty and interest among the "bad boys" of the natural world.
Bill DunsonEnglewood,
FL & Galax, VA
The problem with plumbago- how to think like a butterfly
In our desire to provide sources of nectar for insects, we often are tempted to plant exotic plants which can provide beautiful flowers for the garden and hopefully nourish some of our "flying flowers", the wonderful butterflies. It is not always obvious how to balance native and exotic plants in the garden since certainly one would prefer to use native plants whenever possible. However natives may not always flourish in a given place, and they may not provide abundant flowers at all times of the year. Of course many of us inherited plants in our gardens when we purchased a house and find it difficult to remove flourishing but perhaps non-productive flowering exotics. One problem I face in our yard is that of plumbago, the shrub from S. Africa that is widely planted in Florida, Texas and California. It has pretty blue flowers, blooms profusely and is non-invasive. So is it a "good exotic" to have in the garden? The answer is NO ! But the reason may surprise you- not just because it is an exotic but because its the nectar in its flowers is not available to most insects in N. America. Look at the attached photo I took in our yard of a honeybee hopefully checking out the plumbago for a quick lunch- but to no avail. The problem is that the corolla tube, where the petals are fused into a long tubular structure holding nectar at the bottom, is very long relative to the length of the tongue or proboscis of the bee, or almost any other local insects. Thus they can look but not drink! So this flower is essentially useless as a provider of nectar for butterflies. In its native S. Africa it is known to attract butterflies and to act as a larval food plant. Some birds have figured out a solution to this problem by piercing the base of the flowers and "stealing" nectar.
Another common example of this problem with long corolla tubes is Ixora, the beautiful red tubular flower from India. Once you recognize this situation you can now examine your garden for unproductive flowers, at least from the perspective of hungry nectivores. This will require a fundamental change in your perspective about your garden- to carefully re-examine all of your plants on the basis of their usefulness to butterflies. So get out there and watch each of your flowers and see if the butterflies are actually able to feed from them.
Bill Dunson