Leucadendron argenteum

Thanks once again to Jim, aka J.G. in S.F.@Flickr of San Francisco, California for sharing today’s images (original image 1 | original image 2 | BPotD Flickr Pool). This entry concludes our first series celebrating the International Year of Biodiversity. The next series, on the topic of “Sports and Biodiversity”, will start sometime mid-February.

Silver tree (the epithet argenteum means “silver”) or witteboom is native to the Cape Province of South Africa. As should be evident from the second photograph in particular, reflective silvery hairs covering the surfaces of the leaves are responsible for the common name and epithet. The Protea Atlas Project has this explanation for the hairs on the leaves of Leucadendron argenteum: “…[the] thousands of hairs which cover the leaf…protect the plant from desiccation and herbivory. The intensity of the sheen [of the leaves] varies with temperature and is most pronounced in hot, dry weather when the hairs lie flat on the leaves…During wet weather the hairs stand more erect…and the leaves are relatively drab.”

Leucadendron argenteum is considered vulnerable by the IUCN Red List, noting that remaining populations of the species are threatened by the development of Cape Town, too-infrequent fires, alien invasive species and clearing of land for tree plantations. Fortunately, the largest population of the species is protected within the land maintained by Kirstenbosch National Botanical Garden, allowing for management and monitoring.

An excellent description of this species, including its local distribution, the origin of its name and other historical information, and use in cultivation can be read on Plantzafrica: Leucadendron argenteum.

Leucadendron argenteum
Leucadendron argenteum

7 responses to “Leucadendron argenteum”

  1. Don Fenton

    The genus is popular as garden plants in Australia, at least partly because of their relationship, and resemplance to, our local flora.
    Since you are contemplating a series on “sports”, I hope that the “norms” that they sported from will be included for comparison.

  2. Quin

    many of our fellows will know these as the ‘theme tree’ of the Cape Province Garden at S.F. Botanical Gardens. in the big freeze of ’89 many were killed by three days of sub freezing temps. – quite an educational experiemce for Bay Area gardeners (plumbers too!). many did survive and have gone on to spark a demand among local gardeners. so sorry to hear of them on the IUCN list – sigh. may their beauty be helpful in their survival

  3. Eric in SF

    This is a spectacular small tree and is fairly well represented in public gardens here in coastal California and it’s appearing more and more in private gardens.
    The specimens 90 miles south of San Francisco, in the UC Santa Cruz Arboretum, look a lot better:
    http://www.flickr.com/photos/ericinsf/2260846702/
    http://www.flickr.com/photos/ericinsf/2435955038/
    I think that’s because our summers in San Francisco are pretty cool, rarely going above 75F/23C for more than a couple days at a time. Santa Cruz, on the other hand, is famous for balmy warm summers.

  4. Mary Ann, in Toronto

    Daniel, you were asking for contributions for February’s topic of “Biodiversity and sports”. I don’t have any photos, but did have some thoughts and wasn’t sure where to put them — so posted them on the page where you introduced the topic — on January 22’s page (Cypripedium candidum).

  5. elizabeth a airhart

    just simply beautiful thank you
    daniel with the winter games in vancouver
    how the mountains will be affected and how
    all the vistors impact the area is a concern
    your febuary biodiversity and wood in sports
    will not be hard to write about
    thank you all the comments are so good and helpul

  6. lisa

    What a fabulous tree – How I wish these could grow in the Seattle area.
    I love the story of the hairs rising in damp weather and laying flat in hot dry weather. I’m fascinated with how plants express themselves… Even though I know this done is for practical reasons, I still find it wonderful.
    Thank you for the excellent post, as always.

  7. Daniel Mosquin

    Thanks Mary Ann, I’ve sent them along to one of the student researchers helping me with the topic.

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