Posted on by tonytomeo

V8

The vertical post demonstrates how much the tree trunk leans.

A few tree species should’ve had a V8. That includes more than a few individual trees. It applies to enough individuals of a species to indicate that the need is almost typical of the particular species.

The need for a V8 is derived from old advertisements for the V8 beverage that depicted those who were deficient in adequate consumption of V8 as leaning prominently. V8 is a juice beverage that is composed of juices of eight vegetables; tomatoes, carrots, celery, beets, parsley, lettuce, watercress and spinach. Hence, V8. It balances a diet so that those who consume it stand upright rather than lean.

In horticultural slang, the need for a V8 refers to a leaning trunk.

Any tree of any species has potential to develop a leaning trunk, and consequently appear to be in need of a V8. Some species innately develop leaning trunks though. No one seems to know why, but specimens of such species with vertical trunks are oddly uncommon or perhaps rare.

For example, so many ginkgo trees lean at such similar angles that, among some groups, their distinctive lean seems to be a normal characteristic of the species. It is variable though. Many individual trees that are isolated from others are quite vertical. So are some groups of street trees. However, many or most specimens of other groups of street trees lean at very similar angles, although in random directions.

Italian stone pines are more likely to lean, also at relatively similar angles, and also in random directions. Locally, vertical trunks are rare among this species. However, within their native range, vertical trunks are typical.

Argyle apple (eucalyptus) is almost comparable to Italian stone pine in regard to its typical need for a v8. I have seen a few with vertical trunks. I was determined for ours to be among them. I bound the trunk to keep it straight as it grew. I installed it with the trunk as vertical as the sign post next to it. When wind caused it to lean slightly while it was smaller than it is now, I pushed it back into position. Actually, I might have done that a few time. However, as it matured, it became more difficult to push back into position. Eventually, it refused to budge from its leaning position. Now, like most of the species, this specimen also seems to be in need of a V8.

After the base of the trunk insisted on leaning, the upper portion of the trunk assumed vertical posture.
Posted on by tonytomeo · 17 Comments

Tropism Gives Plants Some Direction

80523thumbWhen a seed germinates, the roots know that they want to go down, and the new stem knows that it wants to go up. Going up sounds simple enough. Stems just go towards the light. How do they know where the light is while they are still under the soil? Well, new stems go upward for the same but opposite reason that roots go downward; gravity. Roots go toward it. Stems go away from it.

Tropism is how plant parts respond to a variety of stimuli, particularly gravity and light, but also water, chemicals, mechanical stimulation, trauma and electricity. Response to gravity is geotropism. Roots exhibit positive geotropism by growing towards gravity. Stems exhibit negative geotropism by growing away from gravity. Stems exhibit positive phototropism by growing towards sunlight.

Roots are always figuring out where to go next by prioritizing their innate positive geotropism, their tropism for or against certain chemicals, and their tropism for moisture but against saturation. Until we see them migrating into lawns, displacing concrete or getting into a septic systems, their work underground is unseen. Tropisms above ground are quite visible and perhaps informative.

When a tall herbaceous plant falls over, it tries to get up. If unable to, it can at least curve new grow upward. Even cut flowers and vegetables in the kitchen can do that much. Snapdragons that are initially arranged leaning outwardly from the center of a floral arrangement can go vertical within a day or two. The fluffiest houseplants regularly get turned so than they do not favor one sunny side.

Trees are too big to move, but on rare occasion, it happens. The crossed pairs of Mexican fan palms commonly planted outside of In-N-Out Burger restaurants get planted at a lean while mature, but then grow vertically after installation, leaving an angular kink where the direction changed. Such a kink in an otherwise straight trunk of a tree that was not planted at an angle might indicate a sudden destabilization. A curved trunk indicates either a slow destabilization, or tropism to escape shade.