Sex in the Grass

I was poking though old posts recently, spotted a minor typo in this one, thought, "what the heck," and corrected it.  That's when I made an important discovery: Blogger moved the post to the current date (from late June 2014 when originally posted), so that it went to the top of the blog.  Now I've learned my lesson, but will add this preamble and bump it once more, now that grasses are again coming into glorious flower

Okay: really "sex among the grasses" would have been more accurate--but would it have gotten your attention?

The grasses in my neighborhood are all hot-to-trot right about now, and that gives me the chance to talk about a pet peeve: the way people use the term "flower."  

A great many people are unaware of most flowering plants because they only notice flowers that are large and showy.  But showiness is just that: a bid to attract attention.  --just not ours.  

Showy flowers are in the business of attracting pollinators, to overcome one of the key disadvantages of the rooted life: an inability to go out dating.  For any sexual reproduction, sperm from the male must get to the egg of the female.  For most animals this is not a problem: they can move.  For plants it is a biggie.

Most plants overcome this problem by enclosing their sperm in a pollen grain, and then having some way to get this pollen grain from the male part (stamen) a longish distance to the female part (pistil) of the flower on another plant.  Most flowering plants do this with the help of animals recruited for the purpose.  These animal "chaperones"* are informed  of a plant's randy status with colors or odors, and  bribed with nectar or the like to be the go-between.  In a typically mutually beneficial arrangement, the animal (whether bee, bat, bird, etc) gets a reward for delivering the pollen to the receptive stigma of a flower on another plant, and then Baby is on the way.  Of course, it's helpful if you and your Honey are in the mood at the same time: hence flowering seasons.    More people should blush at the sight of blatant sex all around them.

Of course, the contented beetles are a good clue, but

how else can you tell that the swamp dogwood above is insect-pollinated, 

but the pignut hickory below is not?

Not all plants use animals as go-betweens.  Some prefer to let their love waft on the wind.  Among these are conifers, of course; the sperm-bearing pollen that pines coat all surfaces with at this time of year is the detritus of a veritable orgy.  But some flowering plants are also wind-pollinated: familiar oaks and maples release pollen from small, inconspicuous flowers with tiny, dull-colored petals because they have no need to attract animals.  One downside of this habit--at least for many of us--is seasonal allergies.  

 A few wind-pollinated trees: Norway maple, scarlet oak, and paper birch.

 

 The grasses go these trees one better: they don't even have petals.  For grasses, in particular, wind pollination makes sense: grasses typically live in in dense stands in which likely sexual partners are close by, so a little breeze is all that's required to complete the tryst. 

A few grasses from my neighborhood.

*In an old and jocular sense, and rather the opposite of what their parents intended.

Who says flowers need petals to be pretty?

Of the large genus of panic grasses, Panicum virgatum is one of the biggest--it is even majestic.  It is a local grass here in Massachusetts, as well as being important in the tallgrass prairie and an important food for livestock.  It has just come into bloom in my yard.

These are a part of the little "prairie garden" of native grasses, goldenrods, milkweeds and the like  I allow to run riot, only cutting it back when it begins to block our driveway.

Only a few days ago, finally taking a close look at the flowers, did I realize how beautiful they are.  Each plump flower in the large cluster is individual.  Pistils extend feathery orange stigmas to catch wind-borne pollen grains from neighboring grasses, while purple stamens in turn release pollen grains to the breeze.

A Few Common Grasses

I have been watching grasses as never before, figuring out their identities,* noting their flowering.  Here, as promised, are a few grasses from my yard--and maybe yours, too. 

Note that you cannot identify grasses always kept mowed.  --I don't know what grows in my own front yard, since we mow regularly for the sake of the neighbors.  But the back yard is another story!  I usually don't mow the back until a few days before the Fourth of July, getting ready to have people over for a cookout.  Then, flowering about done, the backyard sees the mower a bit more regularly.  (One big patch on the side of the house never sees a mower: my little prairie garden of native grasses and forbs.  The only gardening I usually do there is to pull out invasives.)  Even if you are an assiduous mower, there're likely grasses hiding out in un-get-at-able corners that have freedom to flower.


1. First the proper lawn grass: Kentucky bluegrass.  This is one species (native all over the northern hemisphere, but named for a state it grows well in) that is part of the genus Poa.  You can tell members of this genus by their "boat-shaped leaf tips."  (No kidding: if you look close, the end really has the upturned shape of a ship's prow.)  It's a big genus all over the northern hemisphere temperate zone.  

Kentucky bluegrass, Poa pratensis, with its short leaves, delicate flower cluster, branches in the flower cluster in bunches of 3-5, and cobwebby hairs hidden by the lowest flower scales in each flower cluster. 

2. An alien that I happen to like anyway, imported and grown for winter animal fodder, is timothy.  It's easy to recognize with flowers in a tight-packed, continuous flower cluster that would look like a sausage if it weren't so long and slender.  (Another genus, Setaria (foxtail), looks a little like this, but is much bristlier.)   A profusion of stamens marks timothy's flowering.

Timothy, Phleum pratense.  Above just beginning to flower, below in full flower.

 

Two grasses that also have no branches, but with flower clusters alternating up either side of the stem, are English ryegrass, and quackgrass.   The flower clusters in both are flattened.  

3. In the alien English ryegrass, the clusters and stem are in the same plane (making the whole thing flat), and each flower cluster lies in a curve of the sinuous stem.  

4. In quackgrass, on the other hand, the clusters have their flat sides against the stem. 

English ryegrass (Lolium perenne)

Quackgrass (aka witchgrass, couchgrass) Agropyron repens.  

Though native, it can be invasive.  Below in flower.

5. A favorite genus of mine is the switchgrasses or panic grasses: Panicum.  One familiar roadside member is deer tongue, Panicum clandistinum.  Even without flowers it is recognizable for its broad leaves, which persist in winter; when you grasp them gently and pull, tiny hairs resist it sliding past your fingers--supposedly the texture of a deer's tongue.  The branched flower cluster bears single flowers, and each waves a delicate, forked purple stigma when in flower.

Deertongue, Panicum clandestinum.

 

6. Orchard grass grows nearly everywhere--poor soil or good, sunny or shady--and was imported from Europe for animal fodder.  According to Lauren Brown, George Washington thought it "the best mixture with clover; it blooms precisely at the same time, rises again quickly after cutting, stands thick, yields well, and both cattle and horses are fond of it, either green or in hay."  It stands out due to its "bunchy" flower clusters, and short, stiff side branches and rough texture. 

Orchard grass, Dactylis glomerata, gets its species name from the "bunchy" clusters of flowers.

(Think "agglomeration"--ooh, sounds like an SAT word!)  Below, in flower.

7. Another big grass genus is Bromus the bromes.  Bromes all have a bristle at the tip of each flower scale, among other features.  Many bromes have graceful, drooping flower clusters.  Mine, is, I think, smooth brome or Hungarian brome (where it was first cultivated).  It is a coarse grass common on roadsides.  Smooth brome has only the shortest, tiniest bristles--easily missed without close examination.

 Smooth brome, Bromus inermis.

Many people lump the unrelated but grass-like sedges and rushes in with grasses.  (Students of my generation were helped to distinguish them with "sedges have edges, rushes are round, grasses have joints."  Edges, because sedges have three-sided stems (triangular in cross-section).  Joints, because grasses have jointed stems.  I have both sedges (which generally have triangular stems) and rushes in my back yard.  

8. One particular rush is so characteristic of trampled ground as to be named path rush--on hard-packed soil its stiff, wiry form may be the only plant growing.  In our yard it luxuriates in much better soil, growing taller than the six or so inches it would attain on paths.

 Path rush, Juncus tenuis.

 

9. One of the biggest genera in the world--and the largest in eastern North America--is the genus Carex.  These sedges are common, and different species grow in many different environments, but they are difficult to tell apart--many have no generally recognized common names.  The one below might be Carex intumescens.  Pretty much any tussock sedge with shiny plastic-like leaves that you come across would have a pretty good chance of being some kind of Carex.

Carex intumescens(?)

*My go-to grass book is a beautiful little guide by Lauren Brown: Grasses: an identification guide  (Houghton Mifflin  1979).  It is a nice, manageable size, covering most of the grasses in the northeast you are likely to encounter.  The keys are friendly, taking you in a few steps to a small group of pages you can just leaf through.  (Most people--myself included, I'm embarrassed to admit--would rather look at pictures, anyway.)  Brown's lovely ink drawings are reason enough to buy the book.

Attending to Grasses

Today, our first good walk in three days (the dogs and I a bit rain-shy), I made a mental note to mow the front lawn.  But first I needed to take a better look at the grasses before mowing them down.  That led to the idea to attend to grasses on our walk.  A fair number of grasses are in flower, and more have finished flowering and are setting fruit. 

 The grass above is still in flower; you can just make out the stamens dangling from diminutive flowers.

The grass below is finished flowering, and its fruit developing.

Passers-by watched a strange guy crouch on the sidewalk with a camera intent on who-knows-what, while two small dogs tugged at their leashes.  The movement of the delicate stalks with the slightest breeze made the photography challenging; and I quickly decided on plan B: pick a few stalks of whatever looked different, and add it to the growing bouquet in my shirt pocket. (The stranger with camera and dogs got stranger still.)

I lay my finds on the kitchen table, trying to eliminate repeats.  I still find it a little amazing how many different grasses my little suburban neighborhood hosts.  Even the most manicured of lawns usually has a neglected corner--a bit of wild that begins to redeem the property in my eyes.

 The entire pocket collection.  A dozen-odd species, I think.

 Close-ups.

What are their names, you might ask?  I don't know myself.  Call them Tom, Dick, Harry, Hermione...  Their being matters more than their names, after all--just as yours does.  But familiarity is difficult without a "handle"--just as it is in learning people.

So it might be time to brush-up on grass ID.  Subject for a future post, perhaps?