a-b-Bacteriastrum-hyalinum-c-Asteromphalus-arachne-d-Cyclostephanos-sp-e.jpg

a-b-Bacteriastrum-hyalinum-c-Asteromphalus-arachne-d-Cyclostephanos-sp-e.jpg from: https://www.researchgate.net/figure/a-b-Bacteriastrum-hyalinum-c-Asteromphalus-arachne-d-Cyclostephanos-sp-e_fig10_344133292

Macromitrium hyalinum Broth.: A Fascinating Moss of the Orthotrichaceae Family

Macromitrium hyalinum Broth., commonly known as Macromitrium, is a captivating moss species belonging to the Orthotrichaceae family. This tiny but mighty plant plays a significant role in its ecosystems and boasts unique adaptations. In this blog post, we’ll dive into the world of Macromitrium hyalinum and explore its morphology, global distribution, habitat, ecological roles, and adaptations.

Background on Bryophytes and Mosses

Before we focus on Macromitrium hyalinum specifically, let’s briefly review what bryophytes are. Bryophytes are non-vascular plants that include mosses, liverworts, and hornworts. They lack true roots, stems, and leaves, instead having structures that serve similar functions.

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C0568377-Scytonema_hyalinum_cyanobacteria,_light_micrograph.jpg from: https://www.sciencephoto.com/media/1280945/view/scytonema-hyalinum-cyanobacteria-light-micrograph

Mosses are small flowerless plants that typically grow in dense green clumps or mats in damp or shady locations. There are over 12,000 species of moss, and they belong to the division Bryophyta and class

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Bacteriastrum_hyalinum.jpg from: https://www.biol.tsukuba.ac.jp/~algae/PS/Bacillariophyceae/Bacteriastrum_hyalinum/index.html

Bryopsida.

Morphology and Identification of Macromitrium hyalinum

Macromitrium hyalinum is a small moss, usually growing in tufts or cushions. Its stems are erect and sparsely branched, reaching 1-2 cm tall. The leaves are lanceolate, often twisted when dry, and have a single costa (midrib) that extends to the leaf tip. The leaf margins are entire or slightly toothed near the apex.

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post-3-1158045635.jpg from: https://forum.mikroscopia.com/topic/4497-bacteriastrum-hyalinum-lauder/


One distinguishing feature of M. hyalinum is its hyaline leaf base, meaning the basal cells are translucent and lack chloroplasts. The moss produces ovoid capsules on short setae, and the capsules have a peristome (toothed structure around the mouth) consisting of 16 teeth.

Global Distribution and Habitat

Macromitrium hyalinum has a wide global distribution, found in tropical and subtropical regions of the Americas, Africa, Asia, and the Pacific Islands. It grows on various substrates, including tree bark, rocks, and sometimes on soil or decaying wood. The moss thrives in humid environments with moderate to high rainfall and can be found in lowland to montane forests.

Ecological Roles and Adaptations

Like other mosses, Macromitrium hyalinum plays important ecological roles:

  1. Water retention: The dense growth form allows the moss to trap and retain water, helping to regulate moisture in its immediate environment.
    img-z29-1_167.jpg

    img-z29-1_167.jpg from: https://bioone.org/journals/Cryptogamie-Bryologie/volume-40/issue-16/cryptogamie-bryologie2019v40a16/A-Review-of-the-Genus-Macromitrium-Brid-Orthotrichaceae-Bryophyta-in/10.5252/cryptogamie-bryologie2019v40a16.full

  2. Nutrient cycling: Mosses contribute to nutrient cycling by breaking down organic matter and releasing nutrients back into the ecosystem.
  3. Habitat provision: Macromitrium hyalinum provides micro-habitats for various invertebrates and micro-organisms.

Macromitrium hyalinum has several adaptations that enable it to thrive:

  • Desiccation tolerance: The moss can survive periods of dryness by going dormant and quickly rehydrating when moisture is available again.
  • Leaf morphology: The twisting of leaves when dry helps to reduce water loss, and the hyaline leaf base may aid in water uptake and retention.
  • Asexual reproduction: In addition to sexual reproduction via spores, M. hyalinum can propagate asexually through fragmentation, allowing it to colonize new areas easily.
file-20230516-30960-s3vsmi.jpg

file-20230516-30960-s3vsmi.jpg from: https://theconversation.com/the-secret-world-of-moss-ancient-ancestor-of-all-plants-and-vital-for-the-health-of-the-planet-205048

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Macromitrium-prolong01l.jpg from: https://www.digital-museum.hiroshima-u.ac.jp/~museum/habit/moss_habit/Macromitrium prolongatum/Macromitrium_prolongatum.html

Characteristic Description
Family
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large.jpeg from: https://inaturalist.nz/observations/88236610

Orthotrichaceae
Genus Macromitrium
Species M. hyalinum Broth.
Plant Size 1-2 cm tall
Leaf Shape Lanceolate, twisted when dry
Leaf Base Hyaline (translucent)
Capsule Ovoid, with 16-toothed peristome
Habitat Tree bark, rocks, soil, decaying wood in humid tropical and subtropical forests

Conclusion

Macromitrium hyalinum Broth. may be small, but it is a remarkable moss with a fascinating biology and important ecological roles. Its unique adaptations, such as desiccation tolerance and hyaline leaf base, allow it to thrive in various humid habitats across the tropics and subtropics. The next time you find yourself in a lush forest, keep an eye out for this tiny but mighty plant! What other secrets of the bryophyte world await discovery?