That is just what I have observed from growing. You can get a sativa pheno from an indica plant and vice versa.
Having a positive DIF(day temp higher than night) will space out the node growth increasing the likelyhood of alternating nodes. Keeping the day and night temps close and having the plant under intense light will make them stretch less and lessen the liklyhood of even nodes. That is just what I have observed, and I could be wrong.
According to the standard phyllotaxy, cannabis leaves are compound (with multiple leaflets, as opposed to simple, where a single leaf grows from the stem) and decussate-opposite rather than alternate. Opposite leaves emerge in pairs, one each side of the stem, with a clear vertical space between the leaf pairs. Decussate leaves are opposite, but each new leaf pair is at a right-angle to the last pair. Alternate leaves emerge from the stem singly, swapping sides as the vertical height increases.
Although cannabis leaves are usually decussate, as the plant prepares to flower the leaves may begin to emerge in an alternate pattern. Interestingly, rejuvenated cannabis plants demonstrate alternate phyllotaxy. Experiments with hemp showed that early-planted specimens, which flowered in low light conditions but did not die, began to put out new alternate leaf growth when hours of sunlight increased. The initial new growth was simple rather than compound, and as new growth continued, the number of leaflets gradually increased.
There is some evidence that this phenomenon leads to vegetative growth of greatly increased vigour, although the genetic processes responsible are not fully understood. It is thought that the evolution of opposite-decussate phyllotaxy occurred comparatively recently, from an alternate-leaved ancestor, and that the genes controlling the decussate phyllotaxy ‘switch off’ around the time of inflorescence.
Sensiseeds.com
