Friday, February 27, 2015

Observations of Flies

Hamamelis x intermedia
While bees are some of the most famous and loved pollinators, flies are one of the most numerous (along with beetles). I watched as a few common houseflies (Musca domestica) went from flower to flower on this potted witch hazel tree in front of a home improvement store. It has been observed of Hamamelis virginiana, an Eastern US relative of this Asian hybrid pictured above, that the primary pollinators are flies. This makes sense, because often these trees will bloom through snow, a time when bees are surely inactive due to temperature constraints. Flies are more reliable in cold seasons or harsh environments, such as alpine and tundra ecosystems, for providing pollination services to the flowering plants that inhabit such difficult environments.

Crocus vernus 'Flower Record'
Flies are attracted to the same things as bees, but have a much wider palette. While bees seem to have similar tastes to us, sweet or otherwise "nice" smelling plants, flies further are attracted to odors we find disgusting, like rotted flesh or other decomposing matter. The reason for this may be simple, the adults feed off the fine smelling flowers, while the foul scents are where they will look to lay eggs. Foul smelling plants that are known to be fly-pollinated are ScoliopusAmorphophallus, and other Aroids.


The following pictures are of a shrub that I cannot identify. It is a large mounding shrub found in a local Arboretum. The smell, somewhat musky and not unlike the smell of fruit tree blossoms, is detectable from quite a distance, and that is what originally drew me in. Then, upon approaching this plant, I was amazed at the amount of flies attracted to the small inconspicuous petalless flowers. If anyone can ID this plant, or any of the flies, please share!
Update: This was recently identified as Buxus sempervirens, or possibly a similar species. It seems strange that I am so unfamiliar with a plant sold in every Home Depot and every garden center or nursery everywhere, yet able to identify native plants to the family level (at least) in my own backyard and surrounding countryside. I suppose I am a bit biased.


Thursday, February 26, 2015

Bee Observations

Scilla siberica with a bumblebee
Though our nights have been below freezing, our days have been warm and sunny, and a perfect opportunity for bees to forage for early resources. While adult bees feed on nectar (or honey), they need to collect pollen to feed to their young. While nectar supplies carbohydrates, pollen supplies proteins needed for young bees to develop.

Scilla siberica is a good source of pollen and nectar, and is visited by both bumble- and honeybees in my yard. It is most attractive to them when planted in groups or with various Crocus species or cultivars.

Honeybee on Crocus vernus 'Pickwick'

Crocus flowers are spoken of as being one of the best early "bee plants". I find this to be true in general, but not universally accurate from species to species of either Crocus or bee. I saw very few, maybe one or two, bumblebees and honeybees on the early C. chrysanthus and C. sieberi hybrids, yet they are common sights on the Dutch selections of C. vernus, particularly the purple ones like 'Pickwick' and 'Flower Record'.

Honeybee hovering over Crocus vernus 'Pickwick'
One thing is clear, the larger crocuses produce much more pollen than some of the smaller species of Crocus. This is an obvious attractant to different types of bees. This is most noticeable with honeybees, whos workers will collect both nectar and pollen on seperate trips.

To tell what a bee is foraging for on any flower, you must first take a closer look. Bees and even wasps are docile while foraging, typically only being defensive when you get too close to their nest or hive. Honeybees, and possibly other types of bees, will only collect either pollen or nectar primarily per trip, though both collections may be made on a single type of plant.

The bumblebee below is using its proboscis to probe for nectar. If you can get close enough to see this behavior, you will know that the bee is foraging on that plant for nectar. Pollen may be collected while gathering nectar, but it is only incidental. Studies have found that bees practically attract pollen to their bodies by having an almost undetectable positive charge, while similarly flowers are minutely negatively charged, so the pollen "jumps" onto the bees when they get close enough. 

Bumblebee on Taraxacum sp.
When bees are gathering nectar, they are relatively still, with their head pushed down towards the base of the flower, or wherever the nectar is excreted (called the nectary). Pollen foraging is fairly easy to see, as the bees are quite active inside or on the flowers, particularly around or on the anthers, often moving around the anthers to collect as much as possible.

Bumblebee on Anemone blanda
Watching bees, aside from their behavior, you may also be able to see if their pollen sacks are packed, indicating pollen collection being their main objective on that trip. This is mostly true with honeybees, perhaps less accurate with other types of bees.

Bumblebee crawling out of Crocus vernus 'Pickwick'

I have never got around to identifying bumblebees, and my knowledge of bee identification in general is fairly rudimentary. If anyone knows what species this is, I am eager to find out!

Bumblebee perched on Crocus vernus 'Pickwick'
Bumblebees are by far easier to garden for than honeybees. Bumblebees are generalist pollinators just like honeybees, meaning they don't specialize on any one particular plant but visit what is available. However, my observations have shown honeybees to be much more fickle, only foraging on what they deem as "appropriate". One honeybee hive differs from the next, so some hives may make better use of the flowering plants than others. I wonder how they determine which floral resources are best?

Bumblebee queen on small Crocus flower
I watched for a while as this bumblebee queen, easy to identify by her large size (about the length of a quarter), negotiated this reletively small Crocus flower. I'm not really sure what her intentions were, she never really seemed to find a way in. It was like watching a Sumo wrestler attempt to get in the backseat of a Mini Cooper.

Though the bumble- and honeybees have been going nuts for the large Dutch selections of Crocus vernus, solitary bees seem to be uninterested. This one bee, below, was the only solitary bee I observed.

Crocus vernus 'Jeanne d'Arc' with small solitary bee
This white selection of Crocus vernus needs a more sheltered position than others, because in more exposed sites it tends to be very short lived in my experience. It is also the last to open of the large Dutch selections, and works very nicely with the purple and striped forms. It is good in a somewhat shaded site, the bright white flowers standing out against the shadows.

Crocus vernus 'Jeanne d'Arc' with small solitary bee
I would very much like to know what kind of bee this is. My guess based on the basic morphology is that it is some type of Andrena, but I am not an expert entomologist (barely an amateur, more like a blind marksman). If anyone has the answer, I'd like to hear it!

Wednesday, February 25, 2015

Dark and Cold

Brassica rapa var. perviridis
The dew from earlier in the night has frozen solid!
This winter has been a very mild one, night temperatures barely reaching below freezing, until recently. Nighttime lows this week have been in the mid 20's Fahrenheit, and in addition the humidity has been fairly high. This, and the lack of an insulating cloud cover, has produced cold nights with a lot of frost. It is beyond me why the temperature seems to dip lowest right before sunrise, which is when these photos were taken. Taking pictures in these conditions is uncomfortable, but with the goal in mind I barely noticed when my hands went numb from the cold. The things we will do for a good picture...
Crocus sp.
This is the stump planter, with most of the crocuses dying back for the season. There are a few new leaves appearing, but I'm not sure if I'll see any new flowers out of it. This flower had a jewel like appearance. It was far past its prime, and vulnerable to the frost. I used a flashlight, low ISO, and the flash to give it this ethereal luminescence. Even in death, these flowers can hold great beauty in close inspection.


Crocus tommasinianus 'Ruby Giant'
Scilla mischtschenkoana
Pseudomuscari azureum
Despite the cold, I love taking pictures before dawn. The Earth is still, and there are no distractions. These small plants stand out, and are subject to some vulnerability with the darkness creeping in from all sides. One thing I would recommend, is to dress warm and wear some gloves!

Tuesday, February 24, 2015

New Growth #3

Pulmonaria officinalis 
Behold! My Pulmonaria has finally opened a flower! Now that it has begun to flower, it is clear the family ties are true. Being a member of the Boraginaceae, or Borage family, Pulmonaria sp. generally have hairy leaves (among other parts) and a five-lobed corolla that is fused at the base. Also consistent with many in the Boraginaceae, there are hairs, or trichomes, inside the flower protecting the nectar or possibly excluding tiny insects that would be ineffective at pollinating the flowers.

Pulmonaria officinalis
Comparing the one above (seed grown) to the one below (a horticultural selection, a clone), you may first notice the lack of spots in the former. Also note the flowers. My seed grown form has open flowers, while the cultivar below has the typical cup-shaped corollas of most selected forms. To combine the best qualities of both forms would be awesome.

Pulmonaria cultivar
And finally, a color accurate depiction of my plant in situ below. It contrasts nicely with the needle duff, an automated annual mulch that finely coats the area. It also looks like this form reproduces will via division, as there appear to be a number of clonal offshoots surrounding the main plant.
Pulmonaria officinalis
Pulmonaria also goes by the name Lungwort (as well as other "lung" related names in different languages). It was once thought that the spotted leaves of some species looked like diseased lungs, so were used medicinally to treat lung disease. The strange thing is, they were right! The leaves are in fact used to treat a variety of respiratory disorders in the form of a tea or tincture, and are probably also useful as a poultice. However, the plant does contain some toxic alkaloids, so should only be used internally under the care of a professional.

Viola sp.
This species of Viola has popped up in my yard. I'm not sure what it is, but I have planted it close to a group of Viola odorata to see if they will hybridize. It may not work, as many species of violets make seed before even opening their flowers. It's a type of asexual reproduction that created offspring identical to the seed parent (the sole parent).
Viola odorata
Sweet violets are great, gentle companions to many other plants. In this bed, they grow harmoniously with Cimicifuga, Lilium hybrids, Epimedium (below), Pulmonaria, Sanguinaria, and Scilla siberica (also in flower now).

Epimedium cultivar
New leaves of an Epimedium hybrid, though I forget the name. These new leaves are tiny now, roughly 3/8" long, and hard to see. However, I always look for signs of new growth this time of year. In the Autumn when I planted this, something has done in and eaten it to the ground. This wasn't really an issue, as that is something I would have done anyhow. Removing the old leaves lets you see the new growth, and the eventual (hopefully) flowers unobstructed.
Cynoglossum grande
Walking the yard, I found this Pacific hound's tongue on the Eastern edge of the yard under pine and madrone trees. Perhaps a result of the nature of the soil, the leaves of this Cynoglossum have always had a reddish tinge. Peculiar.

Dodecatheon hendersonii
Henderson's stars, as they are often called, are coming into bloom very early this year. This individual is more advanced than any other, the flowers ready to open on any warm sunny day. Early flowering would benefit this species, before other wildflowers come in to bloom and compete for pollinator attention.

Hyacinthus hybrid
Back to the intentional garden, the blue hyacinths I have are further along than the white ones. Even in bud, these are stunning plants. Closely related to Scilla and Hyacinthoides, they are likewise attractive to bees, particularly bumblebees, who may be attracted by the strongly scented flowers.

Narcissus hybrid
An early daffodil in the lawn, my attempt at naturalization. This is a random hybrid that came in a "naturalizing mix" a few years ago. This one, and a few others, didn't flower well last year in a sunny spot at the foot of some conifers, so I moved them to the middle of the lawn to see if they would cope better.

If your plants are suffering, move them. Even a few feet can sometimes make the difference between life and death, or at least good or bad performance. A flowering plant is normally a sign of a happy plant. Make them happy.

Crocus vernus 'Pickwick'
To conclude, here is an excellent Dutch Crocus selection. It rivals the beauty of even the most rare and desirable Crocus species, and is attractive to bees with its copious supply of pollen, but more on that later.

Monday, February 23, 2015

Scilla siberica

Scilla siberica
The genus Scilla (now considered to be in the family Asparagaceae, subfamily Scilloideae) is a beautiful group of plants from Europe, mostly the Mediterranean region. Of all of the 50 or more species (the genus seems to be in a state of confusion, many species being separated from the genus Scilla to new genera), Scilla siberica is by far the most commonly sold. This species is a variable one, with colors ranging from near white to deep blues. Bloom time is also variable, as some are in bloom now while others seem to wait until mid-March. Above in the foreground is a form with magenta margins, though for whatever reason the camera recorded it as pink. Perhaps the blaring sun didn't agree with the white balance settings?

Scilla siberica
The flowers of S. siberica are pendant, probably to avoid the pollen or nectar being diluted by early season rains. This is a common feature of Mediterranean geophytes, along with other strategies like closing at night (or during cloudy weather, another feature of S. siberica in fact). Actually, the Mediterranean receives so much summer rain, it barely qualifies as having a "Mediterranean" climate by the standards of what a "Mediterranean" climate is here in the Western United States!

Scilla siberica
This is one of my favorite spring bulbs. It is versatile, able to withstand a variety of conditions (relative shade, sun, wet, dry, etc.) and deer and rodents avoid it! Slugs, on the other hand don't mind that it is poisonous, and readily snack on the unopened flower buds. This one, however, was never found by a slug. I appreciate the gradient of colors in the scape. From green towards the base, fading to a reddish color, transitioning to the purple pedicels, and finally to the vibrantly blue flowers.

Scilla siberica with a bumblebee

And bees love them! Of course, flower density and placement in a Southern exposure will increase the chances of attracting bees. The Southern exposure gets the late winter sun, so long as trees or a structure aren't blocking it. Bees are more likely to choose flowers in sunny areas, even if they are the same type. It gives me great satisfaction to know that I have planted something from across the ocean, and it feeds the locals! But in the end, it is just a small payment to a great debt.