The curious seeds of an invasive tree

Indigenous to Australia, this Blackwood has spread from Chile to California

Topics: Imprint, Design,

The curious seeds of an invasive tree Specimen #19: Australian Blackwood (Acacia melanoxylon)
This article originally appeared on Imprint.

ImprintThe world is filled with wattles ― 1,350 species, more or less. Of the Acacia genus, in the Mimosa family, wattle trees often have little puffy flowers and long seed pods. Six hundred are native to Australia, but many, such as Australian Blackwood, have been introduced throughout the world.

A hardy tree with strong timber and a shady canopy, the Australian Blackwood is cultivated in habitats from Chile to California. Its prized wood is carved into ukuleles in Hawaii, boats in South Africa, and a collection of small treasures ― pipes, pens, guitar picks ― that would fill a Blackwood-inlay cabinet. Meanwhile, in most of these countries, the trees ― and their seeds ― have spread far beyond their designated territory, making the Australian Blackwood yet another introduced species to embellish on the terms of its invitation.

The seeds are curious things, each wrapped in an unmistakable coral-colored ribbon, and so many. They play a significant role in the tree’s life cycle, and its reputation as an internationally recognized invasive species. They are packaged in a legume that develops just after the flower. Long and thin, the beans twist and constrict as they mature, weaving themselves into a bundle of extravagant curls. Once they have dried, the pods split along both margins, exposing the seeds, which, given the odd angles of the curled pods, flail in every direction. The seeds are small (2-3mm long), and they are fastened to the pod by a reddish-orange seed stalk, called an aril or funiculus, that folds twice around the seed.

The bright accent distinguishes our tree from other wattles (which might have yellow, or cream arils), and it is a bright billboard for birds, a seed dispersing agent―at least in Australia, where birds have evolved to forage on the red aril and disperse the seed. However, many birds in the tree’s new environments are not similarly adapted ― this can keep the tree from wandering where it’s not wanted. Birds in South Africa, however, have developed a taste for the aril. Here the tree’s populations are growing, and it’s believed the birds have something to do with it. The country has declared the tree a noxious weed species, and biologists have taken measures to control it, including the introduction of seed-feeding weevils (and the Australian Blackwood is not the only nuisance; in total, 10 control agents have been released to control 10 Acacia species). In its native country, the tree is also recognized as a problem, which doesn’t diminish its status as a national icon ― Acacia melanoxyln has been featured on two postage stamps, in 1959 and 1966.



The aril is not only pretty; it’s also rich in protein, which makes the seed package rather appealing to ants, which consume the aril and discard the seed, in a fertile rubbish heap, or in the nest. Now buried, the seed has secured itself a pretty good place to wait until it’s time to germinate. Like many Australian natives, the seed has a hard coating, a preference for bushfire germination, and incredible patience ― all of which make for years of dormancy. There is evidence that soil-stored seeds are viable after 50 years. And the tree itself can grow for over 100 years, perhaps even sacrificing a limb or two for a polished wooden treasure.

See more of Anna’s posts in the Botany Blueprint series here.

Copyright F+W Media Inc. 2012.

Salon is proud to feature content from Imprint, the fastest-growing design community on the web. Brought to you by Print magazine, America’s oldest and most trusted design voice, Imprint features some of the biggest names in the industry covering visual culture from every angle. Imprint advances and expands the design conversation, providing fresh daily content to the community (and now to salon.com!), sparking conversation, competition, criticism, and passion among its members.

More Related Stories

Featured Slide Shows

  • Share on Twitter
  • Share on Facebook
  • 1 of 11
  • Close
  • Fullscreen
  • Thumbnails

    Ten spectacular graphic novels from 2014

    Beautiful Darkness by Fabien Vehlmann & Kerascoët
    Kerascoët's lovely, delicate pen-and-watercolor art -- all intricate botanicals, big eyes and flowing hair -- gives this fairy story a deceptively pretty finish. You find out quickly, however, that these are the heartless and heedless fairies of folk legend, not the sentimental sprites beloved by the Victorians and Disney fans. A host of tiny hominid creatures must learn to survive in the forest after fleeing their former home -- a little girl who lies dead in the woods. The main character, Aurora, tries to organize the group into a community, but most of her cohort is too capricious, lazy and selfish to participate for long. There's no real moral to this story, which is refreshing in itself, beyond the perpetual lessons that life is hard and you have to be careful whom you trust. Never has ugly truth been given a prettier face.

    Ten spectacular graphic novels from 2014

    Climate Changed: A Personal Journey Through the Science by Philippe Squarzoni
    Squarzoni is a French cartoonist who makes nonfiction graphic novels about contemporary issues and politics. While finishing up a book about France under Jacques Chirac, he realized that when it came to environmental policy, he didn't know what he was talking about. "Climate Changed" is the result of his efforts to understand what has been happening to the planet, a striking combination of memoir and data that ruminates on a notoriously elusive, difficult and even imponderable subject. Panels of talking heads dispensing information (or Squarzoni discussing the issues with his partner) are juxtaposed with detailed and meticulous yet lyrical scenes from the author's childhood, the countryside where he takes a holiday and a visit to New York. He uses his own unreachable past as a way to grasp the imminent transformation of the Earth. The result is both enlightening and unexpectedly moving.

    Ten spectacular graphic novels from 2014

    Here by Richard McGuire
    A six-page version of this innovative work by a regular contributor to the New Yorker first appeared in RAW magazine 25 years ago. Each two-page spread depicts a single place, sometimes occupied by a corner of a room, over the course of 4 billion years. The oldest image is a blur of pink and purple gases; others depict hazmat-suited explorers from 300 years in the future. Inset images show the changing decor and inhabitants of the house throughout its existence: family photos, quarrels, kids in Halloween costumes, a woman reading a book, a cat walking across the floor. The cumulative effect is serene and ravishing, an intimation of the immensity of time and the wonder embodied in the humblest things.

    Ten spectacular graphic novels from 2014

    Kill My Mother by Jules Feiffer
    The legendary Pulitzer Prize-winning cartoonist delivers his debut graphic novel at 85, a deliriously over-the-top blend of classic movie noir and melodrama that roams from chiaroscuro Bay City to Hollywood to a USO gig in the Pacific theater of World War II. There's a burnt-out drunk of a private eye, but the story is soon commandeered by a multigenerational collection of ferocious women, including a mysterious chanteuse who never speaks, a radio comedy writer who makes a childhood friend the butt of a hit series and a ruthless dame intent on making her whiny coward of a husband into a star. There are disguises, musical numbers and plenty of gunfights, but the drawing is the main attraction. Nobody convey's bodies in motion more thrillingly than Feiffer, whether they're dancing, running or duking it out. The kid has promise.

    Ten spectacular graphic novels from 2014

    The Motherless Oven by Rob Davis
    This is a weird one, but in the nervy surreal way that word-playful novels like "A Clockwork Orange" or "Ulysses" are weird. The main character, a teenage schoolboy named Scarper Lee, lives in a world where it rains knives and people make their own parents, contraptions that can be anything from a tiny figurine stashable in a pocket to biomorphic boiler-like entities that seem to have escaped from Dr. Seuss' nightmares. Their homes are crammed with gadgets they call gods and instead of TV they watch a hulu-hoop-size wheel of repeating images that changes with the day of the week. They also know their own "death day," and Scarper's is coming up fast. Maybe that's why he runs off with the new girl at school, a real troublemaker, and the obscurely dysfunctional Castro, whose mother is a cageful of talking parakeets. A solid towline of teenage angst holds this manically inventive vision together, and proves that some graphic novels can rival the text-only kind at their own game.

    Ten spectacular graphic novels from 2014

    NOBROW 9: It's Oh So Quiet
    For each issue, the anthology magazine put out by this adventurous U.K.-based publisher of independent graphic design, illustration and comics gives 45 artists a four-color palette and a theme. In the ninth issue, the theme is silence, and the results are magnificent and full of surprises. The comics, each told in images only, range from atmospheric to trippy to jokey to melancholy to epic to creepy. But the two-page illustrations are even more powerful, even if it's not always easy to see how they pertain to the overall concept of silence. Well, except perhaps for the fact that so many of them left me utterly dumbstruck with visual delight.

    Ten spectacular graphic novels from 2014

    Over Easy by Mimi Pond
    When Pond was a broke art student in the 1970s, she took a job at a neighborhood breakfast spot in Oakland, a place with good food, splendid coffee and an endlessly entertaining crew of short-order cooks, waitresses, dishwashers and regular customers. This graphic memoir, influenced by the work of Pond's friend, Alison Bechdel, captures the funky ethos of the time, when hippies, punks and disco aficionados mingled in a Bay Area at the height of its eccentricity. The staff of the Imperial Cafe were forever swapping wisecracks and hopping in and out of each other's beds, which makes them more or less like every restaurant team in history. There's an intoxicating esprit de corps to a well-run everyday joint like the Imperial Cafe, and never has the delight in being part of it been more winningly portrayed.

    Ten spectacular graphic novels from 2014

    The Shadow Hero by Gene Luen Yang and Sonny Liew
    You don't have to be a superhero fan to be utterly charmed by Yang and Liew's revival of a little-known character created in the 1940s by the cartoonist Chu Hing. This version of the Green Turtle, however, is rich in characterization, comedy and luscious period detail from the Chinatown of "San Incendio" (a ringer for San Francisco). Hank, son of a mild-mannered grocer, would like to follow in his father's footsteps, but his restless mother (the book's best character and drawn with masterful nuance by Liew) has other ideas after her thrilling encounter with a superhero. Yang's story effortlessly folds pathos into humor without stooping to either slapstick or cheap "darkness." This is that rare tribute that far surpasses the thing it celebrates.

    Ten spectacular graphic novels from 2014

    Shoplifter by Michael Cho
    Corinna Park, former English major, works, unhappily, in a Toronto advertising agency. When the dissatisfaction of the past five years begins to oppress her, she lets off steam by pilfering magazines from a local convenience store. Cho's moody character study is as much about city life as it is about Corinna. He depicts her falling asleep in front of the TV in her condo, brooding on the subway, roaming the crowded streets after a budding romance goes awry. Like a great short story, this is a simple tale of a young woman figuring out how to get her life back, but if feels as if it contains so much of contemporary existence -- its comforts, its loneliness, its self-deceptions -- suspended in wintery amber.

    Ten spectacular graphic novels from 2014

    Through the Woods by Emily Carroll
    This collection of archetypal horror, fairy and ghost stories, all about young girls, comes lushly decked in Carroll's inky black, snowy white and blood-scarlet art. A young bride hears her predecessor's bones singing from under the floorboards, two friends make the mistake of pretending to summon the spirits of the dead, a family of orphaned siblings disappears one by one into the winter nights. Carroll's color-saturated images can be jagged, ornate and gruesome, but she also knows how to chill with absence, shadows and a single staring eye. Literary readers who cherish the work of Kelly Link or the late Angela Carter's collection, "The Bloody Chamber," will adore the violent beauty on these pages.

  • Recent Slide Shows

Comments

0 Comments

Comment Preview

Your name will appear as username ( settings | log out )

You may use these HTML tags and attributes: <a href=""> <b> <em> <strong> <i> <blockquote>