Order Trochodendrales / Wheel Tree Flowers


    Order Trochodendrales

    Trochodendrales, under Division Magnoliophyta, is a small order of angiosperms with members distributed in Southeast Asia. The Trochodendrales trees are primitive with simple leaves, no vessels, small or no stipules, and reduced perianth.

    The Trochodendrales flowers are bisexual and pollinated via wind (Tetracentron) or insects (Trochodendron). The wheel tree belongs to the order Trochodendrales.

    Trochodendrales Families

    Trochodendrales Families

    Order Trochodendrales consists of only 1 family, 2 genera, and 2 species[1]. This group is positioned near advanced Eucotyledon’s base, providing linkage between advanced Eudicotyledons and the more primitive angiosperms. The sole family of Trochodendrales is Trochodendraceae, with Trochodendron and Tetracentron as the two genera. Each genus possesses a single species.

    Trochodendrales Distribution

    Trochodendrales Distribution

    The living species of Trochodendrales are scattered in Southeast Asia.

    • The Trochodendron[2] is commonly found in Taiwan and rarely in Japan. On the other hand, the species of Tetracentron are distributed in China and Nepal. This species is endemic and endangered.
    • Researchers stated[3] that the genome of Tetracentron sinensi will better understand the evolution of eudicots and the vessel elements’ formation.

    Trochodendrales Characteristics

    Trochodendrales Characteristics

    Trochodendrales Flowers and Reproduction

    Trochodendrales Flowers and Reproduction

    Flowers of Tetracentron are tiny and yellowish-green in slim pendulous spikes. They are bisexual and stalkless. The flowers do not have petals (apetalous) but do have 4 sepals, 4 stamens, and 4 carpels. The flowers blossom during June-July. Pollination of Tetracentron species is via wind.

    Trochodendron aralioide is also called Wheel Tree. When the species is flowering, the stamens (70) spread to resemble the wheel’s spokes, hence the name. The star-shaped flowers are greenish in clusters. This species does not have sepals and petals. The flowers can be bisexual or male-only. There are 5-11 0r more carpels partly fused in the bisexual trees. The flowers of Trochodendron are pollinated by insects.

    Trochodendrales Genera Differences

    Trochodendrales Genera Differences

    Tetracentron

    • Members are deciduous trees.
    • The leaves are simple and two-ranked. The margin is serrated, and the lamina has palmate venation. The base of the leaf is broad.
    • The stipules are present.
    • Tetracentron has secretory idioblasts.
    • The flowers are sessile with axillary, pendulous, or spicate inflorescences.
    • Perianth has 0 petals and 4 sepals.
    • Tetracentron has superior gynoecium.

    Trochodendron

    • Members are evergreen shrub to tree.
    • The leaves are spiral. The lamina margin is crenulate with subpinnate venation.
    • The stipules ar absent.
    • Trochodendron has big, branched, sclerenchymatous idioblasts.
    • The inflorescence is terminal.
    • Flowers do not have sepals and petals.
    • Trochodendron has slightly semi-inferior gynoecium.

    Trochodendrales Example Species

    Trochodendrales Example Species

    Trochodendraceae only has 2 genera with a species each.

    • Tetracentron – A study on Tetracentron bark[4] shows the presence of new glycosides from the T. sinense. These compounds showed inhibitory activities significantly when tested against human leukemia cells in vitro.
    • Wheel tree – The Trochodendron is sometimes grown for ornamental purposes. Additionally, they also have medicinal benefits[5].

    Cite This Page

    APA7MLA8Chicago
    BioExplorer.net. (2022, August 17). Order Trochodendrales / Wheel Tree Flowers. Bio Explorer. https://www.bioexplorer.net/order-trochodendrales/.
    BioExplorer.net. "Order Trochodendrales / Wheel Tree Flowers" Bio Explorer, 17 August 2022, https://www.bioexplorer.net/order-trochodendrales/.
    BioExplorer.net. "Order Trochodendrales / Wheel Tree Flowers" Bio Explorer, August 17 2022. https://www.bioexplorer.net/order-trochodendrales/.
    Key References
    • [1]“Trochodendrales”. Accessed February 06, 2022. Link.
    • [2]“Forests | Free Full-Text | The Relic Trochodendron aralioides Siebold & Zucc. (Trochodendraceae) in Taiwan: Ensemble Distribution Modeling and Climate Change Impacts | HTML”. Accessed February 06, 2022. Link.
    • [3]“The Tetracentron genome provides insight into the early evolution of eudicots and the formation of vessel elements | Genome Biology | Full Text”. Accessed February 06, 2022. Link.
    • [4]“New glycosides from Tetracentron sinense and their cytotoxic activity – PubMed”. Accessed February 06, 2022. Link.
    • [5]“Trochodendron Aralioides Herb Uses, Benefits, Cures, Side Effects, Nutrients”. Accessed February 06, 2022. Link.

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