Monday, July 18, 2011

Dinosaur food

During our recent family vacation in Southern Oregon, I came across a plant I’d only seen in photos but had coveted for a long time. In fact, a couple of years ago I ordered seeds, but I never started them because I knew the plant wouldn’t grow in our hot and dry climate. Imagine how surprised I was when I pulled into the parking lot at Azalea Park in Brookings, Oregon just to spot a magnificent specimen of Gunnera tinctoria, or Chilean rhubarb. (Although not related to the common rhubarb, Gunnera tinctoria stalks are eaten in Chile and are described as having a refreshingly acidic taste.)

110712_Gunnera_manicata__34
Yours truly trying not to get pricked by the Gunnera tinctoria at Azalea Park in Brookings, OR
110712_Gunnera_manicata__07
This stand was about 6½ ft. tall by 10 ft. wide

As its common name already says, it’s native to Chile where it’s called “nalca” or “panque” but it also grows in Patagonia and other parts of Argentina. It is closely related to Gunnera manicata found in Southern Brazil. Gunnera tinctoria and Gunnera manicata look very similar and are easily (and often) confused. This article from New Zealand describes the differences, and based on the look of the inflorescence on the plant I saw in Brookings, I’d say it’s a Gunnera tinctoria.

110712_Gunnera_manicata__22
Two new leaves that still have their vase shape. Older leaves appear to flatten out.
110712_Gunnera_manicata__13
Front view of a vase-shaped leaf

On both species of gunnera, thick stalks emerge in early spring from underground rhizomes, turning into what are possibly the largest leaves on any plant. According to Wikipedia, Gunnera manicata leaves can be up to 11 ft. long and 5-6 ft. wide. Gunnera tinctoria leaves are a bit smaller. Either gunnera demands constantly moist, fertile, very well-drained soil in a partly shady position and hates high summer heat. Coastal areas with cool summers which mirror their native habitat are ideal. Brookings, Oregon clearly fits the bill. As much as I wish I could grow gunneras in Davis, I doubt they would make it past mid summer.

Apparently, Chilean rhubarb tolerates a moderate amount of frost (into the teens F as long as the crown is protected under mulch) but the rhizomes will rot if they sit in water-logged soil.

110712_Gunnera_manicata__45
Leaf detail, upper side
110712_Gunnera_manicata__42
Leaf detail underside. Notice the spikes.
110712_Gunnera_manicata__14
Spikes on leaf stalk

What I love most about Gunnera tinctoria is its prehistoric look. I remember seeing drawings of dinosaurs when I was a child, and the plants in those drawings invariably looked like gunneras. It’s easy to imagine dinosaur babies playing hide and seek under these giant leaves! Not surprisingly, both Gunnera tinctoria and Gunnera manicata are occasionally referred to as “dinosaur food.”

110712_Gunnera_manicata__23
Cone-shaped inflorescences (flowering structures) with developing flowers
110712_Gunnera_manicata__18
Two inflorescences
110712_Gunnera_manicata__05
Flowers developing on an inflorescence. It is estimated that one inflorescence can produce as many as 80,000 seeds.

For gardeners living in the right climate, there are few plants that define “exotic” the way gunneras do. I think they would combine very well with horsetail rush, another living fossil, around a small pond or other water feature. If only I lived in such a climate, I’d have a regular grove of dinosaur food!

More posts from our trip to Southern Oregon:

3 comments:

  1. I wish I had known that gunnera don't like the heat. I was excited about growing this plant this year, but it has died (or is just about dead) and is now added to the very long list of plants that I can't grow here. Shoot.

    I would love to see a large specimen in person though. Nice post!

    ReplyDelete
  2. Alan, I hear you! I also wish I could grow gunneras, together with many other large-leaf exotic plants. That's why I enjoy reading gardening blogs--at least I get to experience some of these plants vicariously.

    ReplyDelete
  3. Nice one Gerhard! It is indeed not prickly enough to be left untouched (or tear one's t-shirt to shreds). Don't give up on growing one yet in your location. I reckon it can be done if sited in dappled shade and in permanently boggy conditions so it has constant water supply to the big leaves.

    ReplyDelete