Pipestems, Bogbuttons, Hatpins

Eriocaulon, Syngonanthus, Lachnocaulon

Eriocaulaceae

Polygala cymosa was all yellowed-up today (all photos today by John Bradford)

Today under a cloudless sky John and George risked heat exhaustion humping the camera gear required for John’s photo magic down the West Jupiter Wetland Trail near Jupiter, Florida.  It is May and the wet pine savannas and depression ponds are showplaces for the charismatic megaflora:  (pink) Tuberous Grasspink Orchid, (pinker) Bartram’s Rosegentian, Giant White Top Sedges, (white) Sunnybells, (yellow) Colicroot, (yellow) Xyris species, (red) Lanceleaf Milkweed, and the rainbow array of all the Milkwort species.  And wildlife too—a sweaty deer observed us twice, and we passed by a mud turtle laying eggs with turtle-glee in the warm mud.

Eriocaulon compressum. Soft head, rounded bractlets beneath. All Eriocaulons have rectangular air chambers in the leaf and root.

So many flowers!  So little time (before heat exhaustion)!  Let’s go with one of the most curious choices:  the species complex variably known as Pipestems, Bogbuttons, and Hatpins.  It is seldom a purpose of our blog to sort out individual species in a related complex, although help with that is added below as a boring appendix for motivated readers.  Within our usual radius of bioactivity, we’re talking about approximately seven lookalike species.  Anyone who wants to apply the various English names pseudo-precisely to individual species is, in my humble opinion, nuts, as most observers see pretty much one “look.”  An uncommon arbitrary common name has low value.

These plants have one of the most sophisticated streamlined looks in the savanna—they look stylish and minimalist like something designed by Apple, the I-Wort.  There are three basic components to the design: 1) a usually white or off-white button on top, 2) a leafless stalk holding the button aloft, and 3) a starburst rosette of tough leaves radiating at ground level from the base of the stalk.

Syngonanthus flavidulus. The heads have a golden glow beneath, and flower stalk has gland-tipped hairs.

To start at the bottom, the leaves are works of art.  The photo below of a Brazilian Eriocaulaceae by botanist Marcelo Trovó Lopes de Oliveira is elegant.  The photo shows a microscopic cross section of the leaf, that is, a slice, like a slice of salami at Publix.  Here is an indestructible leaf for all occasions.  There’s a tough outer skin made of thick-walled (red) cells covering the photosynthetic layer immediately beneath.  Then comes the good part, with sort of a science fiction cavern look:  vast hollow chambers in the middle of the leaf, with the leaf veins passing though the chambers suspended on one or two narrow vertical braces.   The veins each have their own protective (red) sheath resembling insulation on a wire, and are cushioned, insulated, and air-conditioned from passing fire or beast, and no doubt most importantly blazing sun and heat.  If the plants are inundated or covered by sediments, the leaves have their own ventilation tunnels. Some are so submersion-tolerant as to be aquarium plants. CLICK Look toward the bottom middle of each air chamber—there’s a little tunnel leading to the intake valves, the stomata on the bottoms of the leaves.  They almost seem “engineered.”

Eriocaulaceae leaf “slice.” Microscope view. Photo credit in text.

Now  climb like an ant up the flowering stalk at the center of the plant to the little white button.  That is not a single flower, but rather the Monocot equivalent of the many-tiny-flowered head in the Aster Family.  Beautiful convergent evolution!—two unrelated families “invented” the same flower heads.  And why pack a hundred flowers into a single head resembling a single flower?  Answer (I think):  one insect pollinator visit pollinated 100 flowers instead of just one.  Incidentally, in today’s plants the flowers are mixed male and female in the same heads.

There seem to be indications in the literature of Eriocaulaceae being wind-pollinated.  I (along with most observers) doubt that, at least as being of primary importance, as the flower heads are eye-catchingly attractive, have no apparent wind-pollination adaptations, and most importantly, have glands in the flowers interpretable as nectaries.  The Internet is rich in photos of Pipewort heads with insect visitors.  Here is one of many CLICK.

Although not documented in the U.S., at least one species in Brazil has flower heads able to close up at night, and/or in response to humidity changes.  And speaking of Brazil,  a couple species serve commercially as everlasting cut flowers, which can be dyed in pretty hues, and for their tough wiry stems as “Brazilian Golden Grass.”   Brazilian golden grass is Syngonanthus nitens CLICK.   Visit also CLICK AGAIN.    Whether this heavy harvest is “good” sustainable tropical production, or too destructive remains to be seen, and may depend in part on ecological studies aimed at enhancing the yield.

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Quick and Dirty (and Localized) Identification Guide to Pipestems, Bogbuttons, and Hatpins in our Blog-o-Sphere

(Remember, I’m not even going to try to associate specific English names with individual species…that would be too contrived.)

Eriocaulon

The larger individuals are species of Eriocaulon, mostly Eriocaulon decangulare (2 feet tall, hard flower heads, pointed bracts on the bottoms of the heads) and Eriocaulon compressum (1/2-2’ tall, soft flower head, the bracts rounded).  A third local Eriocaulon is less common, less conspicuous, and less easy to identify.  Eriocaulon ravenalii is usually shorter then about 8 inches, its heads are grayish (vs. bright white), and  small (under 4 mm wide).  This species is confusingly similar tothose below, but it has a giveaway Eriocaulon characteristic:  small cube-shaped or rectangular chambers in the leaves and roots.

Syngonanthus

We have one species of Syngonanthus and its is easy to distinguish:]]]  usually smaller than Eriocaulon, the stalk has glandular hairs, and the button is golden-yellowish beneath.

Lachnocaulon

There are multiple species of Lachnocaulon in Florida.  These are usually the smallest Eriocaulaceae to see locally, but they can overlap in size with Eriocaulon ravenalii or Syngonanthus.    Lachnocaulon species have dark, branched roots, and usually (with important exception, see below)  hairy stalks.   Unlike Syngonantus, the stalk hairs are not tipped with glands.  In our area, three species are particularly likely to cross your path, literally.  The most common, it seems,  is Lachnocaulon anceps.  Its flower heads are fairly globe-shaped, 4-9 mm across, and white or nearly white.  Annoyingly similar is Lachnocaulon minus, which on average is smaller (with overlap), usually has the hairs on the stalk pointing upward (vs. mixed), and has a smaller (4 mm) flower head a dingy brownish color.   A third species, again similar, is Lachnocaulon beyrichyanum.  Its flower head color varies, and is in the size range of L. minus,  from which L. beyrichyanum differs easily by having hairless (or nearly so) flower stalks.  Lachnocaulon engleri has chcolate-brown heads longer then broad, and hairless or nearly hairless stalks. Good luck!

Lachnocaulon anceps. White head. Bigger then other local Lachnocaulon species. Disorganized hairs on stalk.

Lachnocaulon engleri. The stalks are bare, and the elongate heads are chocolate.