Tetraplasandra facts for kids
Quick facts for kids Tetraplasandra |
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| ʻOhe mauka (Tetraplasandra oahuensis) |
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Aralioideae
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Tetraplasandra
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Tetraplasandra was once a group of flowering plants in the ivy family, Araliaceae. These plants are usually small to medium-sized trees, but sometimes they can be shrubs or very large trees. They grow in moist to wet forests.
Scientists used to think there were as many as 19 different kinds (species) of Tetraplasandra. Other scientists thought there were only six. In 2007, a study suggested there were nine species. By 2010, all these nine species were moved into a larger group called Polyscias subgenus Tetraplasandra. This big Polyscias group will eventually have about 250 species.
The plants that were once called Tetraplasandra show a lot of differences within the group. Most of these species were first described under different names before being grouped together as Tetraplasandra. The main species that represents the whole group is T. hawaiensis.
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Where Tetraplasandra Plants Grow
The plants that used to be called Tetraplasandra are only found in Hawaii. They grow on six of the eight main islands. The islands of Niʻihau and Kahoʻolawe are too low and dry for these plants to grow there.
Some species, like T. oahuensis, T. kavaiensis, and T. hawaiensis, are found on many islands. T. oahuensis grows on six islands, T. kavaiensis on five, and T. hawaiensis on four. Other species are only found on one island.
Growing Tetraplasandra Plants
Some Tetraplasandra species, like T. oahuensis and T. kavaiensis, have been grown successfully in Southern California. They don't like too much heat. However, they are very good at growing in shady places. They also need some protection from strong winds.
Sometimes, in horticulture (the art of growing plants), T. kavaiensis has been mistaken for another plant called T. meiandra. But the real T. meiandra is now considered the same as T. oahuensis.
Unique Features of Tetraplasandra
T. gymnocarpa is a rare tree found on the island of Oʻahu. It's special because its flowers have a completely superior ovary. This means the part of the flower that holds the seeds is located above where the petals and other flower parts attach. This is unusual for plants in the Araliaceae family.
The plants that were once in the Tetraplasandra group have always been known to be closely related to other groups like Gastonia, Reynoldsia, and Munroidendron. Studies of their pollen in 1971 confirmed this. In 2010, all these groups, including Tetraplasandra, were combined into the much larger Polyscias genus. This made the Polyscias genus grow from about 100 species to 159.
Hawaiian Names for the Plants
The Hawaiian people have special names for different groups of Tetraplasandra species:
- T. hawaiensis is called ʻohe.
- T. kavaiensis and T. gymnocarpa are called ʻoheʻohe.
- T. waimeae is called ʻohe kikoʻola.
- T. oahuensis and T. lydgatei are called ʻohe mauka.
- A related plant, Polyscias sandwicensis (which used to be Reynoldsia sandwicensis), is called ʻohe makai.
These traditional Hawaiian names match up well with how scientists now group these plants based on their family relationships.
History of the Name Tetraplasandra
The name Tetraplasandra was first used by a scientist named Asa Gray in 1854. He was writing about the plants found during the U.S. Exploring Expedition (1838-1842). The name comes from Greek words: tetraplasios, meaning "fourfold", and andros, meaning "male" or "stamen" (the male part of a flower).
Asa Gray originally named only one species, T. hawaiensis, in this group. He named the tree later known as Tetraplasandra oahuensis as Gastonia oahuensis, but he wasn't completely sure about its classification.
Over the years, many other scientists studied these plants. They gave them different names and placed them in different groups. For example, Horace Mann Jr. named two new species in 1867. Berthold Carl Seemann divided the Hawaiian Tetraplasandra plants into four different groups in 1868.
In 1888, Wilhelm Hillebrand published the first complete list of plants from the Hawaiian Islands. He created a new group called Pterotropia for some of these plants. However, the name Pterotropia is now considered incorrect because another name, Dipanax, was used earlier for some of the same plants.
Later, in 1898, Hermann Harms combined some of these groups back into Tetraplasandra. He also included a species from Malesia (Southeast Asia) that was later called Polyscias serratifolia.
In the early 1900s, more species were discovered and named, like Tetraplasandra waialealae by Joseph Rock in 1913, and Tetraplasandra racemosa by Charles Noyes Forbes in 1917. However, T. racemosa was later moved to a new group called Munroidendron in 1952.
In 1955, Earl Edward Sherff wrote a detailed review of the Hawaiian Tetraplasandra species. He thought there were 19 species from Hawaii and three from Malesia. However, most of the new species he named are not recognized today, except for T. bisattenuata. Sherff recognized that T. hawaiensis was unique and that other species like T. waimeae, T. waialealae, T. oahuensis, T. lydgatei, and T. bisattenuata were closely related. He also decided that Pterotropia should be combined with Tetraplasandra.
By 1990, a new list of Hawaiian plants recognized only six species of Tetraplasandra. Later, in 2000, a new species called Tetraplasandra flynnii was found on Kauaʻi. In 2005, Tetraplasandra lydgatei was brought back as a distinct species.
In 2007, a study looked at the DNA of eight Tetraplasandra species and their relatives. This study showed that the former Tetraplasandra group was a single, natural group, made up of three smaller groups. T. hawaiensis was found to be a "sister" group to all the others. Another group included T. kavaiensis, T. flynnii, and T. gymnocarpa. The last group had T. bisattenuata, T. oahuensis, T. waimeae, and T. waialealae. The study confirmed that T. bisattenuata should be recognized as its own species again.
Polyscias subgenus Tetraplasandra
In 2010, a big study of plant family trees was published. It showed that six smaller groups of plants were actually part of the very large genus Polyscias. Because of this, the six smaller groups (including Tetraplasandra) were officially combined into Polyscias. This increased the number of species in Polyscias from about 100 to 159. Many more species are expected to be added soon, especially from Madagascar and New Caledonia.
The genus Polyscias has been divided into 11 smaller groups called subgenera. The Polyscias subgenus Tetraplasandra includes 21 species. These species come from the former Tetraplasandra, Munroidendron, and Reynoldsia groups. It also includes some species that were once in Gastonia and other Polyscias groups.
The plants that were once known as Tetraplasandra form a natural group. They are closely related to a group of two species: Polyscias racemosa and Polyscias sandwicensis. These two species used to be in their own separate groups. Together, these 11 species form a "Hawaiian group" and are all native to Hawaii.
Images for kids
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ʻOhe mauka (Polyscias oahuensis)
See also
In Spanish: Tetraplasandra para niños
