Tuesday, March 10, 2015

Trees and Shrubs

Prunus hybrid and the afternoon sun
Our days in the past week have been in the mid 60's and even into the 70's (F), yet with cold nights dipping to freezing, though mostly just above freezing. The warm days have made many buds burst open in a blast of colors blotted all over town. From pinks and whites of plums to yellows and reds in shrubs. What was just bare branches a week ago is now a mass of color. Here's what I've seen.

Prunus hybrid
This plum cultivar adorns the parking lot of my work. I have been watching this tree for years. It may be a surprise, but this mature tree of 20' covered in a thousand blossums barely attracts pollinators. This is in complete contrast to the fruit trees in my yard, the largest less than half the size of this one. When I walk past the plum tree at my house, I hear an audible "buzz" of hundreds of bees, flies, and beetles. Perhaps lack of pollinator activity is indicative of the state of the local environment, similar to deformities of amphibians indicating something is wrong. This tree is in front of a factory in the center of a mixed urban environment. Hmmm...

Forsythia and Chaenomeles
I have seen this shrub as I drive home from work for a few years. These shrubs have integrated into each other, and are apparently quite happy. I haven't had the opportunity to observe these species, as I do not grow them myself, but I am curious if the integration of the two effects pollinator attraction?

Forsythia and Chaenomeles
Though the shrubs have only just begun to bloom, you can imagine the impact on the passersby. Eye catching, indeed.

Chaenomeles sp.
Chaenomeles come from Asia, and are known in the West as flowering quince, though the fruit is not really considered edible. Honeybees are known to visit the flowers, though I haven't observed this directly.

Jasminum nudiflorum
I saw this in front of someone's house on the street, I had no idea what it was. It didn't have a scent, though its morphological characteristics suggest moth or butterfly pollination. (Update: This was recently identified as  Jasminum nudiflorum by Robert Guffanti, thank you Robert!)

Jasminum nudiflorum
Butterfly or moth pollinated plants often share certain identifiable features. The first, and perhaps most obvious, is the relatively long floral tube. This feature excludes short tongued insects from reaching the nectar. Less obvious features are the "landing pad" face of the flower, the location of the stigmas, and the position of the stigma.

Lepidoptera (butterflies and moths) type flowers often differ from bird flowers by being scented, and bird flowers often have the anthers positioned out beyond the flower tube to make contact with the birds body. Lepidoptera flowers sometimes have the anthers concealed in the tube to make contact with the proboscis, though this isn't always the case. The stigma of most flowers in held beyond the anthers in hopes of being dusted with the pollen of another flower rather than themselves.

Arctostaphylos viscida
Manzanita's are developing and opening their flowers very quickly in the recent warm spell we have been experiencing. The flowers are worked by a massive variety of native bees, flies, and, in past years, the odd hummingbird. Ants can also be found on or in the flowers, though I am sure their role is less of that of a pollinator, but rather a possible predator of small pests on the plants. For some plants, the enzymes that coat the body of the ant sterilize the pollen. They are typically there for the nectar.
Arctostaphylos viscida
And here is a view looking up at the typical ericaceous flowers. This lone shrub has flowers that are mostly white, in slight contrast to the pinkish flowers of all of the rest in this plant community. Looking inside, you can see the trichomes that protect the nectar. More on Manzanita next week.

1 comment:

  1. Your mystery shrub is Jasminum nudiflorum, the Winter Jasmine. I love shrubs that bloom on bare branches. Those Chaenomeles are a personal favorite, so wonderful as cut flowers.


If leaving a comment as "Anonymous," please leave your name or contact information.