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Brown's taxonomic arrangement of Dryandra facts for kids

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Robert Brown's way of organizing Dryandra plants was the very first time anyone grouped these plants. Today, these plants are known as Banksia ser. Dryandra. Robert Brown, a famous botanist (plant scientist), first shared his ideas in 1810. He then published a more detailed plan in 1830, which included smaller groups within the main one. Other botanists, like George Bentham and Alex George, later used parts of Brown's ideas in their own plant groupings.

What are Dryandra Plants?

The plants known as Dryandra are a type of shrub. They grow only in the southwest part of Western Australia. For almost 200 years, scientists thought they were their own special group, or genus. Robert Brown first named them Dryandra in 1810.

In 2007, scientists decided to move these plants into the Banksia group. Now, they are called B. ser. Dryandra. There are nearly 100 different kinds (species) of these plants, plus many smaller types.

Robert Brown's First Grouping (1810)

Brown first wrote about the Dryandra group in a science paper in 1809. This paper was published in 1810. In it, he listed 13 different Dryandra species. He did not divide them into smaller groups at this time.

Later that same year, he published his descriptions of Dryandra again. This was in his important book, Prodromus Florae Novae Hollandiae et Insulae Van Diemen.

Here are the 13 Dryandra species Brown listed in 1810:

Robert Brown's Second Grouping (1830)

Twenty years later, Brown released an update to his book. It was called Supplementum Primum Prodromi Florae Novae Hollandiae. He added 11 more species to the Dryandra group.

However, he moved D. falcata into a new, separate group called Hemiclidia Baxteri. He did this because its seed pods (called follicles) always had only one seed inside.

The remaining 23 Dryandra species were then divided into three main sections. Brown based these sections on how many "seed separators" were inside each seed pod. He suggested these groups could be called subgenera, but they are now known as sections.

  • The first section was for species with a single seed separator. This group had the most species and was named Dryandra verae ("True Dryandra").
  • The second section, D. sect. Diplophragma, had only one species: D. bipinnatifida (now B. bipinnatifida). Brown thought its seed pods had two separators.
  • The third section, D. sect. Aphragmia, included four species that Brown believed had no seed separators at all.

Here is a summary of Brown's 1830 arrangement:

How Brown's Work Influenced Others

Brown's way of organizing Dryandra was used by scientists until 1856. That's when Carl Meissner published his own arrangement. Many new species were discovered during this time.

In 1847, Stephan Endlicher changed the name Dryandra verae to Eudryandra. This was the only big change to Brown's classification before Meissner.

Meissner's 1856 grouping kept Brown's idea of separating Dryandra and Hemiclidia. He also kept Brown's three Dryandra sections. However, he divided Eudryandra into eight smaller groups.

Later, in 1870, George Bentham created his own arrangement. He decided not to use Hemiclidia as a separate group. He put D. falcata back into the Dryandra group. He also removed D. sect. Diplophragma. He moved B. bipinnatifida into the Aphragma section. This was because he found that the seed separators were not always there. So, from Brown's original names, only Aphragma was still used by Bentham.

In 1996, Alex George published a new arrangement. He brought back the names Hemiclidia and Diplophragma. But he used them in slightly different ways. Both were given the rank of "subgenus." Eudryandra was replaced by D. subg. Dryandra. Aphragma was kept, but it became a "series" within the Dryandra subgenus.

This arrangement by Alex George was used until early 2007. Then, Austin Mast and Kevin Thiele moved all Dryandra plants into the Banksia group. They did this because they found that Banksia was not a complete group without Dryandra.

Mast and Thiele were not yet ready to create a new detailed grouping for Banksia. So, they moved Dryandra into Banksia as a "series." This caused the least amount of change to the existing Banksia arrangement. Because of this, the detailed groupings of Dryandra, including all of Robert Brown's original groups, are currently set aside.

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