Sunday, February 7, 2016

Early Bee Plants

A honeybee visits Crocus sieberi
Spring is nearly upon us, and a few days of relative warmth have shown that bees and other organisms are ready to go. Crocus are popping up everywhere, both at home (nevermind they are being knocked down by turkeys and eaten by deer) and at work, where last year I spent a lot of time improving the dead industrial landscape in front of my workplace's main office.

A honeybee squeezes inside a closing Crocus chrysanthus
The first of the Crocus to bloom are C. chrysanthus and C. sieberi, both readily available and easy to please, both being partial to a quite dry Summer rest so they may not be restricted by the reaches of your irrigation system. Crocus produce both pollen and nectar, though the latter is only available on warm[ish] days when it is produced in quantity and able to ascend up the floral tube (which extends underground, the true stem only breaches the surface to jettison the seeds), arising to a level that is within reach of a bees' proboscis. Pollen is collected due to it's high protein content to feed developing bees, the rich food source is required to grow healthy bees. Carbohydrates, found in the sugary nectar, are required by adult bees who expend a lot of energy flying and taking care of their colony.

Nectar is a complex substance composed of a large variety of complex sugars. Water is absorbed by the plant, and pushed through a membrane in the flower (the nectary) which combines the sugars with a variety of other plant-specific constituents. Honeybees, as well as some other bees, cannot digest nectar as it is, so they collect it in a crop (the honey stomach, they have two stomachs) and regurgitate it into cells in the hive, now with added microbes and enzymes from their crop, which transform the complex sugars into simple, easily digestible sugars. Once the moisture content drops below 20% (it's a mystery how honeybees know this), they cap the comb and save it for whenever they need it.

A fungus gnat (family Mycetophilidae) is attracted to the Crocus
Other insects have been attracted to the Crocus flowers, including fungus gnats and tiny Chalcidae wasps. They could be attracted for a variety of reasons. First, seemingly most obvious, id the bright color. The purpose of brightly colored flowers, after all, is to attract insects. Many flowers also have markings not within the spectrum that humans can see (there's a lot of information on this). Second is the scent. Most flowers have a scent, even if they aren't detectable by human noses. Aside from the fragrance of the nectar, the petals of many flowers exude fragrances that are intriguing to pollinators. The last attractant is solar radiance, meaning flowers trap and reflect a small amount of heat from the sun (also helps activate fragrances) which alone can be alluring to insects seeking to bask.

Part of the landscaping at my work (designed and implemented by me)
A wide view of part of my redesigned landscape at work. Ignore the white sign and the reflector, they were necessary as there are those who apparently have no idea that something changed and continue to walk through and on the plants (Muggles!). Aside from that, the effort has been highly praised by a large number of my fellow associates and management. Of course, I hope it benefits pollinators and in time creates a thriving micro-environment for insects and perhaps birds.

A variety of pollinator plants at work, surviving the trampling of careless goons
Crocus are everywhere, along with Sedum album, Stachys byzantina, and a freshly planted Yucca, the latter of which I hope will eventually deter people from straying off the clearly marked sidewalk and gravel path. Next up will be some poison oak transplants and blackberry, mulched with thumbtacks and live mousetraps. Something has got to work, so long as I don't have to put up a fence. That would look bad.

Erysimum × 'Walfrastar' (aka 'Fragrant Star')
A perennial wallflower, I have never tried this plant or even this genus. It was a suggestion by a knowledgeable nurserywoman based on the criterion: drought, bees, possible trampling by a herd of animals, heat. The Winter colors are quite stunning! I was told it is not eaten by deer, but this is something I've heard before.

On the hot south side, a variety of plants grow among rocks (including Cardamine hirsuta)
On the opposite side of the front office, the hottest part of the landscape, amended with organic matter, sharp sand, gravel, and a topdressing of pea gravel is host to many Crocus and a few other heat-tolerant plants. There are people who walk through this part of the landscape too, something about a bunch of rock obstacles and flowering plants says "walk on me," I guess. Most of the Crocus are planted directly around the edges of the rocks, so luckily none have been walked on so far.

A bad bay for bees, a great day for photos!
Far far away from work, it is beautiful yet cold and wet. Most days, admittedly, are not bee-friendly at this time, although there is warm weather forecast for the days to come. I caught this scene on my way home, the clouds themselves were at rest between the hills and the air was silent. It was serene, cold, and I hoped to capture that in this image.

Corylus sp., male catkins have protective bracts
Around the rivers and streams, there are a number of trees in bloom, many are worked by bees and are probably the source of the pollen that my bees have been bringing in. In my region, trees are the first wildflowers to bloom. Corylus (hazel) are some of the first to bloom along with Alnus (alder). In flower, the two are very similar but there are some notable differences. First take into account the male catkins. In Corylus, each floret is covered by a protective bract, while male Alnus florets are unprotected (seen below).

Alnus sp., female flowers are cones
The female manifestations of flowers also differ greatly between Corylus and Alnus. In Corylus, the female flowers are produced at intervals along the young branches from axil to branch tips, with exerted pistils similar to Acer rubrum (see below). Alnus has female florets produces in <1" cones (like compressed catkins; the female florets are partially concealed by bracts).

Male Alnus catkins have no bracts, unlike Corylus
Both Alnus and Corylus are fairly common alongside the creeks and rivers at low elevations. Their early bloom means they are probable a valuable resource for early emerging bees, though they are potentially wind pollinated as well. As mentioned a week ago, my bees were bringing in pollen from an unknown source, most likely Alnus or Corylus.

Acer rubrum, female flowers (pistils, no anthers)
Acer rubrum is an early blooming maple, now in bloom. It is often referenced as a good tree for bees, though I cannot attest to actually observing this myself. True to name, many parts of these maples are red; from the new twigs to the flowers and of course the red leaves in Autumn. The trees are interesting from a botanical point of view because of their flowers. Some trees have entirely male flowers, while some have entirely female flowers, this is defined as dioecious. However, some individuals have perfect flowers (functioning male and female structures in each flower) as well as having a gradient of both male and female flowers. This has been dubbed "polygamodioecious" and "polygamomonoecious" [1] and surely other made up names to describe this. There is some significance when pollinators are considered, mainly because female flowers are much less valuable to bees at this time of year than the pollen-producing male florets. A single mostly-female tree would probably not be a big draw for pollinators, I suspect.

Chlorogalum pomeridianum, the wavy-leafed soap plant
And now I have come full circle, showing plants reminiscent of my very first post to this site. Here it is. It is interesting to note that last year flowers and other new growth emerged earlier, a result of the oddly mild Winter we had experienced. This Winter, conversely, was much colder (though not too cold) and in my opinion was very nice. We had snow (!), but unlike two years prior we did not experience the bitter cold and ice that remained on the roads for months. And this year tops the rest because we are expecting our second child within the month! That will be two daughters, twice the fun, twice the stress, and perhaps two more nature observers and stewards of the land.

1 comment:

  1. Hazel (corylus) is one of the most important bee species in Ireland (where I live) and the rest of Northern Europe. No nectar, indeed...but the pollen is vital for rearing brood in March. Willow, of course, is our other great standby, although large swathes of naturalized garden plants such as butterbur (also native, but mostly spread by earlier beekeepers from male clones), the snowdrop species (January through April if you pick the right three subspecies), and crocuses help earlier. I'm not sure if winter aconite is native or naturalized in Ireland, but it is a wonderful plant on an island which often has remarkably warm stretches in the winter given our Northern latitude.


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