Themeda triandra

Taisha completes the series on South African plants and biomes with this entry. It is also her last official day as a work-learn student with Botany Photo of the Day, though there are about a half-dozen other entries she has written that will be posted while the new students learn the ropes. Thank you, Taisha. She writes:

Today we feature the grasslands biome of South Africa with photographs of Themeda triandra, which is known as rooigrass in Afrikaans (“red grass”). These images (image 1| image 2) were uploaded to the Botany Photo of the Day Flickr Pool by Marie Viljoen@Flickr. The first image was originally posted on Marie’s blog, where she later posted a poem about Themeda triandra by South African poet, Antjie Krog. Thanks again, Marie!

The grasslands, also known locally as Grassveld, is the largest biome within South Africa. It is found mainly on the high central plateau of South Africa as well as the inland areas of the Eastern Cape. This biome neighbours the savanna, thicket, and Nama Karoo biomes. This region is relatively flat, though it can vary between sea level and 2850m elevation. The semi-arid to arid grasslands have varying temperatures, with frost being common. Precipitation ranges between 600-1000 mm, with rainfall decreasing westward. The grassland occurs on a variety of soils from humic clays to poorly structured sands.

A single vegetative layer of grasses dominates the grasslands, although other species such as bulbs occur. There are two categories of grassland: sweet veld and sour veld. Sweet grasses occur on the semi-arid regions of the Eastern Cape in eutrophic soils, while the sour grasses can be found in the higher rainfall regions of Drakensberg on acidic soils.

Themeda triandra is a tufted C4-photosynthesis perennial grass occurring widely across parts of Africa, Australia, and Asia. In South Africa, Themeda can occur in the savanna biome, but is primarily found in the grassland biome in regions with rainfall between 500-950 mm and at elevations of sea level-1800m. When young, this grass is a green to blue-green colour tinged pink. It then turns red with age. Rooigrass at higher altitudes tends to be shorter and darker compared to plants at lower elevations. The spikes flower from October to July. Flowers may or may not long black or white hairs. The awned spikelets hang from clusters and are surrounded by reddish brown leaf-like spathes or bracts. Rooigrass does not vegetatively spread long distances, so it is instead an obligate seeder. The long hygroscopic awns twirl when wet, driving the barbed seeds into the ground. There, they will germinate if there is a layer of litter or pioneer plants. This species is noted to be resistant to fire, with resistance increasing if the site is not overgrazed and burnt at regular intervals to allow for regeneration.

Themeda triandra
Themeda triandra

12 responses to “Themeda triandra”

  1. Wendy Cutler

    We’re losing Taisha? Was it something we said, or didn’t say? I know, end of the term, but still, I’m very sorry to hear this. Taisha, I’ve loved your write-ups, so well-written and informative. Thanks for all you’ve given to us.

  2. Knox M. Henry

    Hi/goodbye Taisha: You have done a superlative job. Thank you so much for such informative and interesting descriptions about the plant material that has been featured on botany photo of the day. I confess, I have really look forward to seeing your write-ups. Congratulations and sincere best wishes for your future career. May the grass be green, the snow white and your heart full of joy and happiness.

  3. Connie Hoge

    I wish you could stay, and I wish you health and happiness.
    You have taught me much about plants, and how to write about them.
    Let us know where you are,
    Thank you.

  4. David Tarrant

    I echo the previous comments about Taisha.
    Her impeccable research abilities, followed by writing the facts up in such a a way, that both the layperson and academic could understand and learn. Absolutely invaluable.
    I do hope when you graduate from university Taisha, that you will end up in a position which allows you to continue teaching a greater understanding of the incredible plant world surrounding us all.
    Thank you and long live Botany Photo of the Day

  5. bev

    I don’t comment much but have been faithfully reading Taisha’s posts. I echo the others; best wishes in your future endeavors!

  6. Sara

    My first thought at the photo? Foxtails that dig into everything they touch! Barbed seeds, indeed!

  7. Taisha

    Thank you everyone for the kind comments! I’ve really enjoyed my time helping with BPotD, and although I’m sad to be moving on, I’m also excited for my next endeavours! Glad to have passed on some interesting knowledge, and am looking forward to keeping up with BPotD after the new student starts! All the best!!

  8. kate-v

    Adios, Taisha, your articles have provided me with much inspiration and many happy hours.

  9. Nette

    Taisha was just a student? I’m astounded. Her work is so mature, her descriptions so thorough and eloquent. May she find another venue to thrill us again with images and words.

  10. Helen

    Taisha, I join with many others in wishing yiou godspeed!

  11. Steve edler

    Taisha. I’m really sorry you are going (no offence Daniel). Your write ups are magic especially when you explore a particular theme such as mimicry. You must write brilliant essays for your studies. Just copy all these comments & paste them in your CV.
    I expect to come across your name in the future.

  12. Charles Hines

    Taisha,I have really enjoyed all of your write-ups. I wish you all the success in the world with all your future endeavors.

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