*153684559936880676.jpeg from: https://www.picturethisai.com/care/Bryum_argenteum.html*

Introduction

Bryum sacrum (Lorentz) Müll.Hal. is a fascinating species of moss belonging to the Bryaceae family. This tiny but mighty plant plays important ecological roles and has some remarkable adaptations. In this blog post, we’ll take a closer look at the morphology, distribution, habitat, and ecology of this intriguing moss.

*moss-bryum-capillare-BJR5RX.jpg from: https://www.alamy.com/stock-photo-moss-bryum-capillare-28783662.html*

Background

Mosses are small, non-vascular plants in the division

*jim__stasz_18901428489_8c731731d9_c.jpg from: https://www.marylandbiodiversity.com/view/10651*

Bryophyta. There are over 12,000 moss species found all over the world, from the Arctic to the tropics. Mosses lack true roots, stems, and leaves, but have leaf-like structures called phyllids. They reproduce via spores rather than seeds and flowers.

Moss-samples-of-Bryum-pseudotriquetrum-Hedw-P-Gaertn-A-E-G-and-Sanionia-uncinata.png from: https://www.researchgate.net/figure/Moss-samples-of-Bryum-pseudotriquetrum-Hedw-P-Gaertn-A-E-G-and-Sanionia-uncinata_fig2_318162480

The genus

*INCLINATUM-A-800×600.jpg from: https://www.britishbryologicalsociety.org.uk/learning/species-finder/bryum-algovicum/*

Bryum contains over 800 species, making it one of the largest genera of mosses. Bryum sacrum is one of these many Bryum species.

Morphology and Identification

Bryum sacrum forms small tufts or cushions of green to yellow-green phyllids. The individual phyllids are ovate-lanceolate in shape and have a costa (midrib) that extends to the tip.
The most distinguishing feature of

*5-Bryum_pseudotriquetrum-1024×683.jpg from: https://cumbrialichensbryophytes.org.uk/2021/02/04/bryum-in-cumbria/*

B. sacrum is the presence of red to purple rhizoids at the base of the stems. Rhizoids are root-like filaments that anchor the moss and absorb water and nutrients.

*Bryum-mildeanum-3-1.jpg from: https://www.britishbryologicalsociety.org.uk/learning/species-finder/bryum-mildeanum/*

B. sacrum is dioicous, meaning male and female reproductive structures are on separate plants. The sporophytes (spore-producing structures) have red-brown, elongated capsules.

Global Distribution and Habitat

Bryum sacrum has a wide distribution and can be found in Europe, Asia, Africa, Australia, and the Americas. It grows on exposed, dry, calcareous rocks and soil, often in crevices or on cliff faces. The species is able to tolerate high levels of sun exposure and drought.

Ecological Roles and Adaptations

*medium.jpg from: https://www.inaturalist.org/taxa/159540-Bryum-lanatum*

Like other mosses, B. sacrum plays important roles in its ecosystem:

Helps retain moisture and prevent erosion
Provides shelter and habitat for micro-organisms and small invertebrates
Pioneers the colonization of bare rock surfaces

B. sacrum has several adaptations that allow it to thrive in harsh, dry environments:

Rhizoids anchor it to rocks and absorb trace moisture
Phyllids can quickly absorb water when available
Desiccation tolerance – can survive drying out
Protective red pigments shield chlorophyll from excess UV

Conclusion

Bryum sacrum may be small, but it is a resilient and ecologically important moss species. Its ability to grow on exposed rocks and cliffs makes it a pioneer species that paves the way for other plants to establish. Next time you see a small cushion of moss eking out a living on a boulder, take a closer look – it might just be the mighty

General-morphology-of-Pogonatum-A-male-gametophytes-with-perigonia-on-the-top-B_Q640.jpg from: https://www.researchgate.net/figure/Pogonatum-subtortile-Muell-Hal-A-Jaeger-A-female-gametophytes-with-sporophytes-B_fig9_331675612

*Bryum-argenteum-3.jpg from: https://ohiomosslichen.org/moss-bryum-argenteum/bryum-argenteum-4/*