Thursday, August 4, 2011

A palm that’s not a palm

Quickly, which common “palm” isn’t a palm?

If you said “sago palm”, you’d be correct. While there are other plants referred to as “palms” even though they’re not related to the true palms—cabbage palm (Cordyline australis) or ZZ palm (Zamioculcas zamiifolia) come to mind—the most common non-palm must be the sago palm (Cycas revoluta).

The sago palm, or king sago palm, is actually a cycad, a member of an ancient group of seed plants whose origin goes back more than 200 million years. They were especially abundant during the Jurassic period (from 208 to 144 million years ago), the Age of Reptiles that saw the rise of the dinosaurs. Some experts say that cycads are the oldest living plants on earth.

Cycads grow very slowly (as you will know from personal experience if you’ve ever had a sago palm) and can live very long—some up to 2,500 years. That’s why a great deal of patience is required if you buy a small plant. Usually, there is a flush of new leaves once a year, in ideal conditions (lots of heat, water and fertilizer) twice a year. Eventually, a trunk will begin to form from the bases of old leaves that have dried up and fallen off.

Our potted sago palm is now 12+ years old and it’s still only 3 ft. tall by 4 ft. across.

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Our own potted sago palm

That’s tiny compared to the specimen I came across on Sunday when photographing the bamboo grove at Sacramento’s Capitol Park. This one has multiple trunks and is tall enough to allow adults to play hide-and-seek.

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Mature sago palm at Capitol Park in Sacramento.
Notice the banana and bamboo groves on the left and in the back.
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Mature sago palm at Capitol Park in Sacramento

I was excited to see that this particular sago palm was had cones. Like all cycads, sago palms are dioecious, meaning that there are female plants and male plants. The specimen at Capitol Park was clearly a male.

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Male sago palm
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Male cone

Male plants produce a cone covered with scales under which the pollen is developing. When the pollen is “ripe,” the scales open, emitting a sweet odor to attract insects that will carry the pollen to a receptive female plant nearby. After the female cone has been pollinated, it will produce seeds, which are the size of a walnut when mature.

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Male cone

At Capitol Park, there was no female plant. However, I did photograph one at the Royal Botanic Garden in Sydney, Australia on our last visit. The female cone is a slightly flattened sphere which opens up when ready to be pollinated and closes again after pollination. From the looks of the cone in the photo below, this one was either still immature, or it had already been pollinated.

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Female cone

If you’re now wondering whether your sago palm is a male or a female and how to tell them apart, I have to disappoint you. There is no way of knowing until the plant produces a cone. That doesn’t happen until it’s 15-20 years old. According to cycad expert Lynn McKamey of Rhapis Gardens, the plant must also be well established in the ground. She has never seen a potted specimen cone.

Around town I see a lot of sago palms planted in the ground, and I imagine many of them will produce seed cones in due time. I’ll be ready with my camera when that happens.

As for our specimen, I prefer to keep it in a large pot since it looks more impressive that way, at least while it’s still a juvenile.

7 comments:

  1. Hide and seek? Okay, I'm "it" -- you go hide in that plant.

    Hope you have a lot of band-aids in your pocket.

    I once saw a segment on "Gardening by the yard" about a guy who grew cycads from seed. Fascinating!

    my recent post about my own sago palm

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  2. What? You've never played hide and seek in full body armor?? It's fun! :-)

    For some reason, this mature sago palm didn't seem to be as prickly as my much smaller one. Maybe you're better about keeping your distance when the leaves point at your face rather than your midsection.

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  3. Mine are still just leg-height. I usually get poked right above the knee.

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  4. Alan, ours is in a large pot, which raises it up considerably.

    I was a friend's house today, and their three sago palms (two in-ground, one in a pot) have noticeably softer leaves. I wonder if there are different cultivars, or whether climate is a factor?

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  5. Sago Palm is such an architectural plant, despite being more commonly available amongst all Cycads I still gravitate towards them whenever I spot them on our nursery rounds. A gorgeous specimen planted out or in a pot is always a sight to behold :) They have several in Madeira that are more than a hundred years old, oh for a mild climate :)

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  6. Last fall I almost bought a nice-sized Dioon edule for $30 at a local nursery. Now I regret I didn't, because it was a very elegant plant as well. I'm reading up on cycads, and the more I find out, the more I'm attracted to them.

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