Thursday, September 24, 2015

The Daisy Family, Part 1

Leopard's bane, Doronicum pardalianches
Daisy, from 'Day's Eye' in Old English, a flower opening with the dawn and closing at dusk, is forever linked to sunny faces and carefree spirits.

Chicory, Cichorium intybus
The unifying trait of the daisy family is its composite flower construction. Compositae family members come in many colors and configurations.

Pearly everlasting, Anaphalis margaritacea composed of disc and ray flowers
Composites give the impression of being a single flower. The inflorescence actually consists of a central cluster of many petal-less disc flowers (yellow in the photo above) encircled by strap-like ray flowers.
Fall dandelion, Scorzoneroides autumnalis consists of ray flowers only
The  ray flowers generally have five petals each, greatly modified to attract pollinators. The minute notches at the end of each dandelion ray trace the originally separated petals of each flower in the composite.

Exceptionally, dandelions have no disc flowers.
Rayless chamomile, Matricaria discoidea with disc florets only
On the other hand, the button-shaped rayless chamomile consists entirely of disc flowers whose corollas are fused into tiny tubes.  Their pollination is primarily accomplished by flies.

Tansy, Tanacetum vulgare
The tansy is likewise composed exclusively of disc flowers. It  colors them brightly enough to attract a wide range of pollinators.

Ragweed, Ambrosia artemisifolia
Composites with wind-pollination strategies have forsaken eye-catching flowers altogether. Plants in the ragweed and artemesia group release copious pollen into the air, a major source of allergens to humans.
Blunt-leaved rabbit-tobacco, Pseudognaphalium obtusifolium
Evolving from a common origin, or at least a common principle, the Compositae have diversified along ingenious pathways of species development. A family gathering of composites presents whimsical personalities.
Three-leaved rattlesnake-root, Nabalus trifoliolatus
Nabalus trifoliolatus flower detail
Mouse-ear hawkweed, Hieracium pilosella

Spotted Joe-Pye weed, Eutrochium maculatum
Yellow thistle, Cirsium horridulum
Bull thistle, Cirsium vulgare
Tall lettuce, Lactuca canadensis
Familiar though we are with lettuce foliage few of us would associate it with the daisy family. By the time these head-high flowers bloom at Halibut Point there is little about the basal leaves to remind us of a culinary staple.
Woodland sunflower, Helianthus divaricatus
But sunflowers proclaim their composite nature unmistakably.

Ox-eye daisy, Leucanthemum vulgare 
And of course the ox-eye daisy carries the daisy message over hill and dale as the emblem of summer gaiety.

 In searching out the scope of the daisy family at Halibut Point I have encountered about seventy species in thirty-six different genera. They are more or less conspicuous, and more or less distinguishable from one another.
In September the most complex branches of the Compositae, asters and goldenrods, brighten every corner of the landscape. I look forward to bringing them center-stage in next week's essay.

Thursday, September 17, 2015

The Pea Family

Beach pea flowers, Lathyrus japonicus
If you've grown sweet peas or garden peas, you'll instantly recognize their relative growing on the shoreline. Beach peas share the Leguminosae * family resemblance in clusters of flowers and 'bean' pods.
Beach pea pods at Halibut Point tide line
Beach peas clamber over anything their tendrils can grasp, in a modest way. Its ambitious cousin wisteria aims to entwine acres of trees.
Wisteria pods high in a tree
Wisteria japonica flowers
Wisteria's foliage, flowers and fruit are visibly pea-like.

Black locust in bloom, Robinia pseudo-acacia
Black locusts extend the diversity of the legume family to include tall woody trees on Halibut Point.

It could be said that botanical evolution culminates in the dicotyledons that contain our most familiar flowering plants. Among the distinctions that give them a different 'look' from monocots are the pair (versus single) of embryonic leaves, the netted (versus parallel) vein pattern in the leaves, and the flower parts in fours or fives (versus threes). Contrast the pea family with grasses and lilies as charted above.

Legumes have always been nutritionally important to mankind. The pea family includes beans, soybeans, chickpeas, alfalfa and peanuts.
American groundnut, Apios americana
Groundnuts (wild beans or Indian potatoes) produce tubers that were a staple food for Native Americans, and an important factor in the survival of the Pilgrims during the first few winters of their settlement. Pound for pound they contain three times the protein of potatoes, ten times the calcium, and twice the iron. **

As a member of the legume family the groundnut's ability to supply its own nitrogen in partnership with  soil bacteria could be a great advantage in comparison to root crops that require extensive fertilization. But because it has not yet been coaxed into yielding significantly enough in a single season it has not been assimilated into modern agriculture.
Red and white clover, Trifolium pratense and T. repens

Palmate hop clover, Trifolium aureum
Also found at Halibut Point are two other species of the genus Trifolium, Lesser hop clover (T. dubium) and Pinnate hop clover (T. campestre); as well as members of the genus Meliolotus, white-sweet-clover (M. albus) and yellow-sweet-clover (M. officinalis).

Various clovers have been extensively cultivated as livestock fodder plants, either sown alone or in a mixture with ryegrass to form a staple crop for silaging. They are also welcome in pastures and meadows as a nectar source by beekeepers.
Rabbit-foot clover, Trifolium arvense
While not a forage crop, the nitrogen-fixing properties of rabbit-foot clover enable it to prosper in lean soil locations.
Cow vetch, Vicia cracca
Vetches have made similar contributions to both natural and agricultural ecologies as clovers, enriching soil, planted as green manure in crop rotation plans, favored as livestock feed.

Like many legumes they host rhizobia bacteria within structures called root nodules. These bacteria have the ability to convert nitrogen gas  from the air into a form that is usable to the plant. Nitrogen fixation results from a classic symbiotic relationship beneficial to both organisms.
Four-seeded vetch, Vicia tetrasperma

Crown-vetch, Securigera varia

Bird's-foot-trefoil, Lotus corniculatus

Bird's-foot-trefoil, with many of the same utilitarian qualities as vetch, presents a startlingly beautiful wildflower in impoverished soils. A double-flowered variety has been introduced to horticulture.

Blue lupine, Lupinus polyphyllus
Last year, when a presently lawn area in the State Park grew luxuriantly as a meadow, lupines bloomed in profusion.

Lupine seeds are large and edible enough to have been used as a food for over 3000 years around the Mediterranean and for as much as 6000 years in the Andean highlands.
The legume family is unrivaled in its combined ornamental and comestible value to mankind.
* Most authorities use the name Fabaceae (from Latin faba for 'bean') for the pea family. I prefer to retain Leguminosae, an older name still considered valid, for its reference to the fruit of these plants, which are called legumes.
** I derived much of the information in this essay from pertinent Wikipedia articles

Thursday, September 10, 2015

Dragonfly Episodes

About a month ago on a morning walk to see the swallows swooping over the Halibut Point quarry Kay and I found ourselves in a cloud of dragonflies. Large emerald-sparked creatures tumbled and darted around us intent on business we knew very little about. It happens that dragonflies are another of Chris Leahy's specialties.

Chris Leahy making a point
We didn't actually need to snare anything to profit from an orientation tour with Chris. He recognized Wandering Gliders, the most global of all dragonflies, zooming around the periphery of a field at the Park entrance, moving through on their extended migration. He suggested that our 'cloud' had been composed of Common Green Darners, similarly massing for migration.
Green Darner on the wing
Some of the Green Darners linger at Halibut Point, but  I'd never seen one at rest. They fly at speeds up to 60 mph. Being green, they're hard to locate in a tree. You're much more likely to see one take off than land. I staked out a pond to attempt a flight photo.

Green Darner, pretty good photo
Focusing on a spot in their circuit, the shutter set at 1/2,000 of a second, I waited for a dragonfly to sprint through the frame at just the right distance from my camera. After a morning's vigil I had one pretty good photo that revealed something about the versatility of dragonfly flight. Each wing works independently for maneuverability akin to aerial jackrabbits, if jackrabbits could hover and dart backwards. Helicopter pilots can only dream....
Newly emerged Green Darner
About this time I caught sight of a stationary Green Darner still sporting the purple tint of a teneral, the soft-bodied muted-color phase of a newly adult dragonfly.

Slender Spreadwing at rest
Close-up photographic quests revealed eye-popping populations around the pond. In this setting my best option was to find a comfortable perch in the muck and let them come to me, a guest in an intimate world.
Slender Spreadwing pairing
Eventually, from the comfort of home I ordered three library books on dragonflies. It turned out that all three came from the Children's or Young Adult sections. I pondered why.
Twelve-spotted Skimmer
Everything about a dragonfly's patterns and abilities seems outlandish, made to order for young imaginations.
Yellow-legged Meadowhawk
The names convey the whimsy of a young mind aligning observation with fantasy.

Violet Dancer
The masters of flight with translucent wings and vivid markings draw substance from light, sparking the air.
Ruby or Cherry-faced Meadowhawk
While photographic pursuits sometimes interfere with direct experience, the camera can magnify a dragonfly moment and retain a souvenir.  As an end in themselves the photos spurred my search for novel sightings.
Spot-winged Glider
Dragonflies have a notable place in folklore around the world. The associations are often diabolical, perhaps alluding to their seemingly supernatural life histories.

Slaty Skimmer
Shamanic traditions link dragonflies with transformation. A series of metamorphoses takes them through their underwater years to their brief fulfillment as aerial champions. At each step they set aside a tributary form to adopt new skills and identities. This developmental pageant proceeds from a tiny seed that evidently directs their mastery of successive environments.

Familiar Bluet
Modern scientific tools have permitted insights to the wonders of dragonfly anatomy, the interior hydraulic systems, the coordination of 30,000 eyes within the eyes, the interactions of tissues and organs. You can find a dynamic portrait in The Dazzle of Dragonflies by Forrest Mitchell and James Lasswell.

Painted Skimmer
By taking to the skies dragonflies choreograph their romantic fulfillment, find promising new habitats, and mesmerize their human admirers.

A Guide to Northeastern Dragonflies and Damselflies, a laminated pocket portfolio developed by Chris Leahy, is available for $4.95 from Mass Audubon Online Shop.

Thursday, September 3, 2015

Pond Secrets

Pickerelweed Pontederia cordata in bloom
Generations after quarrymen blasted pits into the granite of Halibut Point, water-dwelling communities come to flourish where none had been before.

Slender spreadwing
Dragonflies arrived to patrol the air over the water. They spend their early life stages as nymphs in the murk below.
Eastern Forktail on a water lily pad
Lily pads float on the interface between the aquatic and the atmosphere.

Water bugs
Water bugs skitter unconcernedly across the surface.

Amphibians at home in both worlds keep their secrets to themselves.

Water lily
A pollinator on wings earns its exchange with a flower.

Dragonfly exuvia
A Green Darner dragonfly nymph climbed out of the pond last night under the cover of darkness. It wriggled out of its exoskeleton, pumped blood into its wings, freed itself for flight.
Blue Dashers
A pair of dainty Blue Dashers courts on the promontory of the stick.

Blue Dashers mating
The couplers initiate a new generation of dragonflies in a heart-shaped union, symmetrically with the Green Darner's shell.

A resting Green Darner, Anax junius
Across the pond a Green Darner rests in the shrubbery. It's getting ready to live up to its forceful name, Anax (emperor, lord, military leader) Junius (a Roman male name).

A Green Darner in flight
I watched the Green Darner take off on a circuit around the pond, scattering the diminutive Blue Dashers.
A tattered Blue Dasher
The Blue Dasher is no match for His Lordship Anax junius.

Out of the depths,
up the pickerelweed stems.
The next night more Green Darner nymphs clambered out of the pond for their nocturnal molt.
Perfect casting
One partnered with a pickerelweed flower. It cast off its body-cast in a theatrical embrace.
A Blue Dasher in 'obelisk pose'
Fortunately for the smaller dragonflies the Green Darners moved on to other environs. The Blue Dashers are free to relax. One does a handstand in what their admirers call 'the obelisk pose.'

Immersed frog
Half in, half out of the pond the bullfrog ponders its opportunities. It too lived a formative phase wriggling on the bottom where dragonfly nymphs prey on tadpoles.

From their aqueous origins dragonflies take to the air in diverse patterns as we shall see in next week's essay.