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This weekend let’s go out and look for trees that are flowering. Whether you walk around the block or visit an arboretum, I bet you are going to discover more than you realize.

Certainly you are going to find trees with beautiful, colorful showy flowers like this desert willow. The buckeyes, horse chestnuts, tulip trees, catalpas, magnolias and fruit trees all have attractive flowers.

desertwillowflower

Do you have any ideas who might come to visit these flowers? In our desert willow we regularly have hummingbirds and carpenter bees. We’ve also noticed tiny birds, called verdins, poking around the flowers. The hummingbirds are collecting nectar, the bees collect pollen and nectar, and we aren’t sure what the verdins are after. They are probably drinking nectar, but they also catch insects. In the summer they love to eat the tomatoes in our garden. We forgive them though, because they are so tiny and cute.

You might have trouble spotting the flowers on certain trees, like this mesquite. They form catkins that don’t have petals, so may not look like flowers at all. Insects often pollinate trees with big, showy flowers; trees with small flowers may be wind pollinated.

mesquiteflower

Other tree flowers may be oddly shaped or peculiar compared to annual flowers. Check out the bell-shaped flowers from a bottle tree (Brachychiton populneum). From the side the flowers are whitish, and are hard to see. Facing the flower, however, the interior is dark red.

bottletreeflower

If you have studied flower parts, then tree flowers can offer some challenges. Sometimes trees will only have male flowers or only female flowers. Mulberries are examples of trees that have separate sexes. One tree will be female and produce fruit and seeds; another will be male and produce only pollen.

It's a good idea to jot down the date when you see trees in bloom. Recording the time of bloom gives information about phenology or dates of reoccurring natural phenomena. This information can then be used to study how plants respond to such things as weather and climate changes. Each tree has it’s own time to bloom and over the years you will see patterns.

If you can’t get outdoors, or you are interested in seeing more photographs of trees, check out the beauties at Julie Walton Shaver’s Tree Growers Diary. The Autumn in the Land Movie is particularly worthwhile if you love trees.

Believe it or not, flies are not my favorite insects, but there is an abundance of them in my garden right now. Do I have garbage out there? No, some very unusual flowers are attracting the flies, like the flower shown here. If you were sitting where I was to take this photo, you would think there was a garbage pile nearby. The odor was quite unpleasant.

euphorbia

This plant is a succulent in the genus Euphorbia. The plant deceives carrion and dung flies by producing odors that mimic decay. The flies are expecting to find some yummy rotting flesh or droppings to eat and lay their eggs on, but instead only find a devious plant.

Here is a fly that has been tricked:

fly on euphorbia

As it turns out, another similar plant is also flowering in my yard this week. This plant has bizarre red, star-shaped flowers. It is called Stapelia. It also mimics carrion.

flystapelia

Here is a green bottle fly that has been fooled. I have often seen thin white eggs in the centers of the Stapelia flower, laid by confused flies.

Take a look at this close up. You can see the pollen on the bottle fly’s thorax (behind the head). These plants are misleading the flies in order to be pollinated, and it seems to be working.

greenbottlefly

Carrion-mimicking flowers can go to real extremes to attract their pollinators. Two of the largest flowers in the world are big stinkers. The Rafflesia flower can be three feet wide, making it the biggest flower. The titan arum is definitely the tallest, reaching up to seven feet! Check the Library of Congress for some amazing pictures.

Hopefully the backyard jungle will smell better next week.

Some of you may have been wondering how watching birds (from weekend science fun this week) could be science. As I mentioned earlier, observing is an important science skill. Many famous scientists and inventors started out by observing nature, for example Leonardo da Vinci.

I have spent a lot of time recently thinking about how people become scientists. There seems to be a pattern that the interest is developed at home, usually from interacting with a parent or close relative. But a curiosity about the natural world also seems to be a factor.

If you have some time, listen to the podcasts at Ask-A-Biologist, or read the transcripts. The host of the series asks many of his guests about their path to becoming scientists. The answers are quite illuminating.