Source: PNAS | Mobile Abstract Cladoxylopsida included the earliest large trees that formed critical components of globally transformative pioneering forest ecosystems in the Mid- and early Late Devonian (ca. 393–372 Ma). Well-known cladoxylopsid fossils include the up to ∼1-m-diameter sandstone casts known as Eospermatopteris from Middle Devonian strata of New York State. Cladoxylopsid trunk structure comprised a more-or-less distinct cylinder of numerous separate cauline xylem strands connected internally with a network of medullary xylem strands and, near the base, externally with downward-growing roots, all embedded within parenchyma. However, the means by which this complex vascular system was able to grow to a large diameter is unknown. We demonstrate—based on exceptional, up to ∼70-cm-diameter silicified fossil trunks with extensive preservation of cellular anatomy from the early Late Devonian (Frasnian, ca. 374 Ma) of Xinjiang, China—that trunk expansion is associated with a cylindrical zone of diffuse secondary growth within ground and cortical parenchyma and with production of a large amount of wood containing both rays and growth increments concentrically around individual xylem strands by normal cambia. The xylem system accommodates expansion by tearing of individual strand interconnections during secondary development. This mode of growth seems indeterminate, capable of producing trees of large size and, despite some unique features, invites comparison with secondary development in some living monocots. Understanding the structure and growth of cladoxylopsids informs analysis of canopy competition within early forests with the potential to drive global processes. If I understand the structure described, it would be more like a coral, a structure with a lot of tubes. Bob Wilson
This tree wannabee has linear tubing in the direction you'd expect. Superficially similar to modern wood. Modern wood, with variation among species, averages more than half holes. I think holes in corals are about the same in any direction.
Balsa wood is 88% open by my calcs. Pretty much not there. Densest woods (ebony and above) have very little open space. To drive in a nail you'd better make a pilot hole. Wood's holiness is rather underappreciated and I am trying to avoid making typically long post. It would be full of holes
Somebody was offering a kit car that used balsa wood for the frame. Beyond that my tree knowledge is really rusty.
It was a South American company, and the car was designed to be cheap transportation; think TaTa Nano with a wood frame like a Morgan. Balsa is an inexpensive lumber there that the owner/builder could get locally.
Bamboo also has good strength to weight because of big hole in middle. Trees as such never explored hallow growth forms. Bamboo, being a grass, was much more recent and an independent innovator. Must...resist...temptation
Our subject paleo tree superficially resembles palm to my eye. They are extremely distant in evolutionary terms. One might speculate that 300 million years later, palms 'said' "this has not been done in a while - let's give it a shot"
Termites will eat bamboo. They have very broad diets. At the same time there are woods they completely ignore. Choice seems unrelated to structure - just a few % of 'tastes bad' sends termites to look elsewhere. Good defense if there are many other species around. Not so good in plantation monoculture. Bamboo as some will know, erupt from the ground very rapidly. Very distinct from classical wood. They can toss leaves up to well-lit places and get photosynthetic payoff before termites find them. Grasses were rare or absent before big rock labeled 'bye bye dinosaurs' hit Earth.
It is just limited when it comes to wanting square building materials. I do like our bamboo cooking utensils.
We put a spreading bamboo in our backyard, a decade or two back. Was not thinking. Wonderful stuff, but I regret it I guess. Spring and summer I have to keep at it, knocking back the shoots. We're the neighborhood bamboo connection, lol. May have to throw in the towel, get someone with a backhoe in there one of these years.
Yes bamboo has reputation for taking over gardens. Spoz to bury an 'oil drum' first, then plant bamboo inside.
Bamboo growth forms are not OT for me! But a return to paleotrees would take us to 'all that coal'. How the long run of dinosaurs witnessed forests from looking really weird, to quite modern. A long run that has not been equaled, unless you are a clam fan Whenever somebody gets giddy about Grand Canyon's sweep of fossil history I am tempted to mutter "yeah, clams, great".
