Hypothesis on the relationship between T.princeps and nova.

Today, I walked along the road after a cool afternoon and a strange idea came into my mind after seeing the nova of about 1.4-2.5years old I am growing in hundreds which are already 13-25cm trunk definitely unlike standard T.fortunei.

The following observation is based on 2.5 years growing experience with princeps and nova seedlings from seeds in the stone gate.

1.T.princeps seedling,

narrow leaves ,narrowly and evenly divided leaflets. apparent white powder on leaf upper surface, beneath and petioles. normal seedlings. smaller and difficult to germinate seeds

2.T.nova seedlings,

narrow leaves,narrowly and evenly divided leaflets, no white powder.slender seedling,bigger easy to germinate seeds.

3. T.fortunei seedlings,

irregularly divided leaflets in term of leaflet width and spacing.

stronger seedlings .bigger and easy to germinate seeds.

I know my ideas may sound crazy but still I'd like to speak it out .

T.princeps and nova are more closely related than other Trachycarpus and could be from the same species -T.fortunei ,evolving and diverging then over thousands of years into different evolution forms at different stages due to the distinct growing conditions ,one at the steep cliff, the other at the foot of mountains.

Both species are from the stone gate area and have narrow seedling leave as well as narrowly and evenly divided leaflets, as opposed to irregular ones of T.fortunei.If nova are not stretched and no white powder is present, they do resemble T.princeps. We have seen some nova do look more like princeps.This explains their close relationship partly. However T.fortunei seedlings set them apart from the two forms by first glance of their irregular leaflets.

Some would say princpe are totally different from nova by blue tinge because of white powder presence.That is right. But their different growing conditions can explain these differences.

1.The reason why leaves and leaflets of both forms are narrowly divided is that it could be protective response to avoid the harm from the strong ultraviolet radiation in this high elevation area reflected by the fact that local residents like Tibetan ,Musu nationality,and Dulong nationality are all darker in skin than inlanders like us. T.princeps growing at the steep cliff as high as over 2000m in altitude could be the most to be hurt by ultraviolet radiation and dramatic day and night temperature fluctuation in the stone gate where even the normal fluctuation sees as high as 20C like in winter at the mountain foot.So they develop their special protective mechanism of presenting white powder on leaf upper surface ,underneath and petioles like some desert palms whereas nova in the shadier area of the mountain foot don't need it but otherwise compete for the sunlight by vigorously and vertically stretching out the slender trunk and enlonged petioles.

Over thousands of years of evolution history, the different climatic and ecological differences contribute to their current unique growth performance.

2.The seed size and germination difference indicate their nutrition and climatic conditions in their distinct growing areas.The more fertile, the bigger the seeds and the better developed seeds.The reason why T.princeps have a difficult germination and require a long postripeness is that their rigorous conditions make them not physiologically well developed in one life circle though morphologically mature and so they need a longer postripeness to be mature before germination .

More photos of comparison can be viewed here