Wednesday, July 25, 2012

My First Blooming Compass Plant!

I think it was two years ago now that I first noticed a compass plant or two or twenty in the Back Five.  Their leaves are so distinctive that it's one of the few native perennials that's easy to identify, even without seeing it bloom.

About 18 months after we moved in, I attended a Lunchtime Lecture at Botanica where Brad Guhr of Dyck Arboretum was speaking.  He had brought along several compass plant bloom spikes, with some open blooms, spent blooms and young seed on them.  After the talk, he offered the bloom spikes to anyone who wanted them - I grabbed one? two? ten? (I can't remember now) and brought them home, scattering the seed in the Back Five.  The young seed wasn't fully mature yet, so I wasn't sure if there was even a chance that any compass plants could establish.

But they have!  The photo to the right is the first bloom spike for a compass plant that I have seen on our property!  I took this shot on the 4th of July - a great American find on a great American holiday.  I am 5'6" tall;  this flower spike is my height or a little taller, just to give you a little sense of scale. 

My seed-scattering history aside, I think this particular plant - and maybe one other one - may actually have predated my restoration efforts;  these two plants are so large that they may be remnants from the original prairie here.  On the other hand, most of the compass plants that I see now throughout my little acreage have two or three leaves this year and are far from blooming.  Since compass plants are supposedly like trees, with a leaf for every year of life, at least when they are young, this plant would appear to be much older than our measly 5+ years of "occupation," while the littler ones would seem appropriate for seedlings from the seed Brad so generously shared.

The scientific name of compass plant is Silphium laciniatum, and this tallgrass prairie native is found throughout much of the middle of the country.  Its common name is derived from its foliage:  the large, thick, sandpaper-textured leaves with their deep lobes tend to align pointing north to south, minimizing the exposure of the leaves' sufaces to the hot, noonday sun, but capturing plenty of light throughout the mornings and afternoons.  Pioneers apparently used this plant to help themselves navigate.


Although the basal leaves grow up to about 2' in width, the real size of the compass plant comes from its flower stalk, which can tower up to 12 feet above the prairie soil.  The flowers look very similar to sunflowers, but if you look closely there is a major difference:  unlike sunflowers, only the ray (or petal) flowers are fertile in these blossoms.  Therefore seeds are only produced around the rim of the dried flower head.

Typical of a prairie native, the roots of compass plant grow very deep - up to 16' - helping it to survive dry times with panache.  There would probably be more compass plants around except that cattle find it very tasty and will eat it to the ground so frequently that the plants soon lose all their energy stores and die.  In the last few years, though, I've been seeing a fair number of compass plants along the roadsides in certain areas - on the turnpike south of Topeka, for example, and in Butler County along some of the country roads - where the main grazers are grasshoppers and bush hogs.

If you choose to plant compass plants in your garden, be careful about siting them correctly from the very beginning, as their deep tap roots make them hard to transplant once established.  Know that they will grow quite tall and be sure to plan accordingly.  For prairie gardens, they can be a particularly nice addition since their large leaves add a unique texture with a coarse feel, a rather unusual combination in the normally "medium" textured prairie palette.

Birds relish compass plant seeds and many use the dried stalks to perch on while they're overlooking the grasslands.  There are even 2 species of insects, the silphium beetle and the prairie cicada, that are specialist feeders on compass plants and others in their genus.  I have never seen either of these insect species, so I can't show you photos, but one of these days I hope to remedy that lack.


Compass plants flower from the top of the flower stalk down.  Almost 3 weeks after I saw the original blooms, the flower spike looked like this on Monday.  Busily munching away were these beasties....


...known as two-striped grasshoppers (Melanoplus bivittatus).   Two-striped grasshoppers are common creatures of town and country.  They can become quite destructive, eating a wide variety of plant material, including some crops such as alfalfa.  Here they are performing their more classic function, acting as the primary herbivore (grazer) on the prairie - in this case, eating the flowers of the compass plants.


This morning I couldn't resist taking another photo of the compass plant.  The drought and heat is even taking its toll on this stalwart prairie plant, but it's gamely continuing to bloom, even as some of its basal leaves turn brown and die.   You can see that its bloom period is probably not quite half over, since the open bloom is about 1/3 of the way down the bloom stalk. 

We have a 30% chance of rain tonight and tomorrow - the best chance we've had in weeks.  We're all keeping our fingers crossed and doing literal and figurative rain dances.  Wish us well!

12 comments:

Kalantikan said...

Wow, i didn't know there is a compass plant! I only know of the sunflower which always points its flower to the sun. And we also have some flowers we either call 'alas dies' or 10:00 oclock and 'alas cuatro' or four o'clock. Those are Spanish terms so i guess we got it from the Spaniards centuries ago! You have a wide prairie area, do you plant trees there too?

Janet, The Queen of Seaford said...

Saw my sister's posting on FB showing a big storm coming over your area. Hope you got some rain from it! Very interesting information on the Compass Plant. I bet I saw a lot of them driving through Kansas, thinking they were sunflowers. Don't you love 65 mph plant ID's?

Jason said...

Great compass plant. I don't have those, but I have another plant from the same genus, cup plant. There should be more of these Silphiums in gardens. Could be grown like hollyhocks, only no rust!

Gaia Gardener: said...

Andrea, your comments remind me of our 4 o'clocks (which may be the same as yours - Mirabilis sp., I think) and our genus Oenethera, known as evening primroses - all of whose whose flowers open in the late afternoon and close in late morning the next day.

I'm actually trying to get rid of most of the trees in the prairie area we're restoring. Trees shade out the prairie plants and serve as outposts where predators hang out to hunt the prairie obligate species. Our prairie is only 5 acres and a little more, but we do have meadowlarks and a few other prairie birds that nest there.

Gaia Gardener: said...

Janet, thanks for your well wishes! They may have helped, because we got about 1/10" of rain overnight and there are still some interesting looking clouds in the area. I'm keeping my fingers crossed!

One of the reasons I like to drive is to do both 75 mph plant ID and 75 mph bird ID! (We're a red state - we make a point of not worrying about gas mileage or global warming, so we get 75 mph speed limits.) When it's heading out, big bluestem and Indian grass are both easy IDs at that speed as are many of the prairie wildflowers, including compass plant. (Compass plant blooms before sunflowers, and it's easy to see the leaves at the base of the bloom stalks.) There's so much to see that I have to be careful to remember to watch the road!

Gaia Gardener: said...

Jason, That is an awesome plant substitution! The compass plant stalks will also stay upright, even in very windy sites. The only difference I can see is that hollyhocks will take more shade than compass plants would be comfortable with. What a great idea!

tina said...

It's lovely and looks much better than mine. I don't think mine like the shade so must move one soon. Thanks for the info I hope it is not too late to dig one up-I just planted it last year.

~Gardener on Sherlock Street said...

A perfect prairie plant. I learned a lot. Don't know that I could give them the space they need in my garden. I hope yours continues to do well.

Gaia Gardener: said...

Tina, I must admit that I've never seen compass plant growing in anything but full sun, so I'd sure try and transplant the one you have in shade. They're great plants, though - and I love Jason's idea of using them, generally, where you might use hollyhock, since they have a similar size and texture.

Gaia Gardener: said...

GonSS, I went to a talk by Benjamin Vogt (of The Deep Middle blog) last night. He gave a great presentation and one of his points was that he likes having tall plants in his garden because then he can see what's going on without stooping. I'm not sure that I agree with his concept for a front walkway garden, where you have to take the sensibilities of unknown visitors into account, but he makes an interesting point for a more private (i.e. backyard) site. Using his rationale, maybe you'd have room for at least one, somewhere, after all!

~Gardener on Sherlock Street said...

Well, I do have that front lawn to remove still. ;-) I also have some arborvitae which will likely come out by the alley. I'm thinking taller stuff would work there. Sometimes, I just need to mull it over. Thanks for all your info and inspiration.

Gaia Gardener: said...

I fully understand the need to mull it over. Actually, I have two modes when it comes to garden design: 1) thinking about it forever, and 2) buying the plants and just finding some sort of spot that fits their growing needs to stick them in. For better or worse, the latter predominates and thus my gardens are never likely to be on a garden tour! :-)

Oh, by the way, replacing the arbor vitae in the alley with some compass plants (and other biggies) sounds perfect. The front might work, too, but at least in the alley you could "trial" them and see how best to use them in a more widely visible spot.