Scientists from the Sainsbury Laboratory at Cambridge University and Jagiellonian University, Poland made the discovery while undertaking an evolutionary survey of the microscopic structure of wood from some of the world’s most iconic trees and shrubs.?

They found that Tulip Trees, which are related to magnolias and can grow over 30 metres (100 feet) tall, have a unique type of wood. This discovery may explain why the trees, which diverged from magnolias when earth‘s atmospheric CO2 concentrations were relatively low, grow so tall and so fast. This opens new opportunities to improve carbon capture and storage in plantation forests by planting a fast-growing tree more commonly seen in ornamental gardens, or breeding Tulip Tree-like wood into other tree species.

The discovery was part of an evolutionary survey of the microscopic structure of wood from 33 tree species from the Cambridge University Botanic Garden’s Living Collections. The survey explored how wood ultrastructure evolved across softwoods (gymnosperms such as pines and conifers) and hardwoods (angiosperms including oak, ash, birch, and eucalypts).?

The wood samples were collected from trees in the Botanic Garden in coordination with its Collections Coordinator. Fresh samples of wood, deposited in the previous spring growing season, were collected from a selection of trees to reflect the evolutionary history of gymnosperm and angiosperm populations as they diverged and evolved.?

Using the Sainsbury Laboratory‘s low temperature scanning electron microscope (cryo-SEM), the team imaged and measured the size of the nanoscale architecture of secondary cell walls (wood) in their native hydrated state.

Microscopy Core Facility Manager at the Sainsbury Laboratory, Dr Raymond Wightman, said: “We analysed some of the world’s most iconic trees like the Coast Redwood, Wollemi Pine and so-called ‘living fossils‘ such as?Amborella trichopoda, which is the sole surviving species of a family of plants that was the earliest still existing group to evolve separately from all other flowering plants.

“Our survey data has given us new insights into the evolutionary relationships between wood nanostructure and the cell wall composition, which differs across the lineages of angiosperm and gymnosperm plants. Angiosperm cell walls possess characteristic narrower elementary units, called macrofibrils, compared to gymnosperms.”?

The researchers found the two surviving species of the ancient Liriodendron genus, commonly known as the Tulip Tree (Liriodendron tulipifera) and Chinese Tulip Tree (Liriodendron chinense) have much larger macrofibrils than their hardwood relatives.

Hardwood angiosperm macrofibrils are about 15 nanometres in diameter and faster growing softwood gymnosperm macrofibrils have larger 25 nanometre macrofibrils. Tulip Trees have macrofibrils somewhere in between, measuring 20 nanometres.