Showing your roots

A common theme of lockdown – at least among people I’ve been talking to – is that we didn’t manage a haircut before we went into Level 4. Mostly we’ve just let it be (and hopefully Level 2 is around the corner) but there are a few doing their own retouching dye jobs to hide their roots.

Which is kind of an awkward segue into a post about showing off your roots but my excuse is a case of lockdown fatigue!

Learning to manage a tree’s roots to dwarf it is an inherent part of bonsai culture and there’s also a term for the style of showing some natural surface roots – nebari, or root flare. Read an article about working the roots of a bonsai here.

A bonsai maple in the collection of bonsai master Kunio Kobayashi in Tokyo. Photo: Sandra Simpson

Another Japanese plant technique, nearai, isn’t often seen in the West. Nearai refers to pot-grown single plants or mixed plantings that, when the pot is full of roots, are removed and displayed on a flat container. The purpose is to show off the plant top and bottom, and I’ve read that the roots can be washed for a more dramatic effect, although, presumably, washing off the soil would shorten the time plants could be displayed. Most of what I’ve read suggests that nearai is a relation to both bonsai and kokedama. It actually sounds quite puzzling!

From the small to the huge! Memorable wedding photos amid the giant roots of a Ficus (fig) tree in Bali Botanic Gardens. The tree is believed to be more than 100 years old. Photo: Sandra Simpson

In the northeast Indian state of Meghalaya, the Khasi people make living bridges using the aerial roots of the tree Ficus elastica (rubber plant). The living bridges strengthen themselves over time due to adaptive secondary growth and the roots growing together. A 2019 report in Nature claimed that the living bridges provide the ‘only known example of repeated, predictable use of tree growth for structural purposes’. Read the full (technical) report here or see the Wikipedia entry.

This living root bridge, at 50m-plus, is the longest known. Photo: Ansel M Rogers, via Wikimedia

The Khasi don’t know how long they’ve been making bridges like this, but the earliest written record appeared in a British journal in 1844.

Autumn is the time to appreciate the outstanding tree that is the swamp cypress (Taxodium distichium) but unfortunately lockdown has prevented a visit to the beauties at McLaren Falls Park. (Apparently, the rangers are asked every autumn about the trees that are dying in the lake but this is one conifer that not only likes to grow with wet feet, it also changes colour in autumn to a vibrant rusty-orange and drops its needles.)

A swamp cypress growing in Lake McLaren near Tauranga. Photo: Sandra Simpson

The other odd thing about these trees are the ‘knobbly knees’ that grow around its base. This is about as large as they get at the park, but in the wild they can apparently be several metres high.

Two researchers at the University of Kansas have proved by experiment that at least one function of these protuberances is to gather air for the tree’s submerged roots, but admit they might have more than one function, including to give the tree some stability in wet or swampy ground, or maybe a storage organ for food.

The technical term, by the way, for a root that gathers air for its tree (mangroves, for another example) is pneumatophore, literally an ‘air stalk’.

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