![]() ![]() It brings us back to the fascinating question of what plants know, and how they know it. And this underground search for food is anything but dull. Parasite is from the Greek for ‘next to’ (para) and food (sitos), thus giving us ‘next to the food.’ Which, while accurate, is pretty dull. ![]() So, while they are not symbiotic, with obvious mutual benefit to both plants, they really aren’t vampires, despite my inability to resist the title. That fast cycle has another possible good effect: they quickly return nutrients to the soil through their decaying leaves. Taking advantage of the mature, deep roots of the perennial plants around them means a ready source of nourishment and water, allowing them more vigorous growth in their short life. Castillejas are usually biennials, growing from seed one year, blooming the next, and dropping their seed to germinate the following spring. That sounds like a negative, but one of its effects may be to allow more diversity in an area by preventing one or two species from dominating. You can see the spiky green flowers, protected by the bracts, as well as the fine white hairs that many Castilleja share.Ĭastillejas don’t kill their hosts, though studies have shown that the hosts are less robust than they otherwise would be. Coast Indian paintbrush (Castilleja affinis) Solstice Canyon, Malibu, California. About 10% of the 270 parasitic genera are invasive pests, causing serious problems for farmers, and capable of killing hosts in natural settings. It certainly benefits the parasite, and some do no discernible harm, but most affect their hosts in some way. At first glance, it’s hard to see why evolution thought this was a good idea. Some are completely parasitic some, like the Castilleja, partially, or hemiparasitic. Castillejas have recently been put into the Orobanchaceae, a whole family of parasites. There they find water and nutrients to supplement their own photosynthesizing. They send out haustoria, specialized roots that penetrate the host’s roots, slithering between cells. That means they can photosynthesize, but usually find a host to help out, often a grass or sagebrush, but it can be other flowers and shrubs, as well. They have green leaves on the stem below the bracts, and then a cluster of leaves at the base. They are everywhere, irresistibly gorgeous, and fascinating, because they’re parasites. A white one shone in the shade at the edge of the woods in Waterton Lakes, and a red one, along a woodland path, glittered in a shaft of sunlight. I found a red one on fire against the bright rock of a Utah trail, and a chrome yellow one in front of a blackened log in a burned forest. The luminous yellow Alaskan native does the same thing in the long summer twilights. On a cloudy day, high on a mountain in British Columbia, were alpine versions - one red, one magenta - that glowed in the muted gray light. As common as they are, it’s impossible to take them for granted, because they change with the available light, so you never know what you’re going to find. Paintbrushes are also white, pink, yellow and purple. The colorful bracts do the job that petals normally do: lure pollinators, especially butterflies and hummingbirds. ![]() Though the flowers are bright green, they can’t hold a candle to the brilliance around them. These surround and protect the inconspicuous flowers, whose petals wrap around each other, forming a tube. The vivid color is not the flower, but modified leaves called bracts. In most places they’re hard to miss: many are as vivid a red or orange as you can find, they usually stand one to two feet tall, and they grow in patches. There is one species in the 250-strong family that grows in the east, but I’d never seen one before coming west. They grow in almost all conditions except swamps or deep woods and are able to withstand toxic serpentine soils when they have to. In other words, if you’re west of the Mississippi, it’s easy to find Castilleja. I haven’t yet seen them in Wyoming, but it’s the state flower, so I know they’re there. Then Colorado and Utah, British Columbia and Alberta, and then Alaska. Then again in southern California, and then northern. I first saw a paintbrush, a member of the Castilleja genus, in Idaho. ![]()
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