The DYCs of Autumn

 

Tick Seed (Bidens aristosa).  One flower is being pollinated
by a bee-mimic Hover Fly (Syrphidae). 
Rowan County, North Carolina. 

In spring the palette of wildflower color runs toward blue and purple, but as summer eases into fall the predominate flower color is yellow.  Many of these yellow blooms are sported by members of the Composite family, the Asteraceae.  This large family includes many familiar plants like sunflowers, asters, daisies and dandelions.    Many of the fall Composites look similar and are difficult to tell apart. Some folks call then DYCs, Damn Yellow Composites.  

Composite is no longer the accepted name of the family Asteraceae but is descriptive.  What looks like a flower in many Composites is actually a group of flowers, an inflorescence.  Many inflorescences of the Asteraceae are a composite of two distinct types of flowers, disk flowers and ray flowers.  Take a sunflower for example; the outer edge that appears to be petals is really a group of ray flowers and in the center are hundreds of disk flowers. This display looks like a single giant flower to insects that pollinate the plant. 

Here is a collection of DYCs of autumn we see in our little slice of North Carolina.  

Smallanthus uvedalia, Bear’s Foot is an impressive plant.  It has large lobed leaves that resemble a bear’s paw.  This tall plant blooms in late summer and fall with an inflorescence of yellow ray and disk flowers.  

Bear Paw, Smallanthus uvedalia, with its large leaves and yellow
flowers, blooming by a stream.
Mecklenburg County, North Carolina. 

Another tall DYC is Wingstem (Verbesnia alternifolia).  It also has yellow ray and disk flowers but the disk flowers are sparse and that gives the inflorescence an unkempt look. As the common name suggests, the stems of the plant has ridges that look like wings running down their length.  Wingstem usually grows along the sunny edges of streams. 

Verbesnia alternifolila, Wingstem, has yellow ray and disk
flowers.  The stems are winged.  This one is being
pollinated by a Scolid Wasp, Scolia dubia.
Rowan County, North Carolina. 

Wings on the stem of Wingstem.
Rowan County, North Carolina. 

Tickseed, Bidens aristosa, grows in open fields and edges of woods.  This is another plant with yellow ray and disk flowers.  The fruits of Tickseed have two prongs and attach to passing animals or the pants of hikers, spreading the plant. 

Tick Seed flowers.
Rowan County, North Carolina. 

Tick Seed Fruit.
Rowan County, North Carolina. 

Bidens bipinnata is a close relative of Tickseed with the common name Spanish Needles.  It has deeply dissected leaves and makes small inflorescences with just a few yellow ray flowers.   The fruits are long with prongs at the end and are dispersed by animals in much the same way as Tickseed. 

Spanish Needles (Bidens bipinnata).
Henderson County, North Carolina. 

Purple Sneezeweed (Helenium flexuosum) has yellow ray flowers and purple-brown disk flowers.  The ray flowers are tipped with three lobes.  The leaves and flowers of this plant were once dried and ground into snuff, giving rise to its common name.  

Purple Sneezeweed (Helenium flexosum).  This DYC has
yellow ray flowers and brownish purple disk flowers.
Henderson County, North Carolina. 

The most emblematic DYC of autumn is Goldenrod (Solidago sp.).  There are over 30 species of Goldenrod in our area and plants fill the fields and line the roadsides with their yellow flowers in fall.  Goldenrod makes numerous, small inflorescences containing both ray and disk flowers.  These are arranged along the tips of stems making sprays of gold.  

A field of Goldenrod (Solidago sp.). 
Rowan County, North Carolina. 

Closeup of the yellow ray and disk flowers of Goldenrod.
Rowan County, North Carolina.  

Fall is flying by and the DYCs are starting to fade.  But amateur botanists everywhere look forward and dread the coming of autumn and the reappearance of these challenging yellow flowers. 

Tick Seed flowers.
Rowan County, North Carolina. 

The Pond Apple and the Reptiles

 

Green Iguana (Iguana iguana).
Green Cay Wetlands, Palm Beach County, Florida.

Pond Apples are fruits made by the Pond Apple tree (Annona glabra).  This tree is native to Florida, the American tropics and west Africa.  True to the name, Pond Apples grow in swamps, beside lakes, along rivers and, yes, on the margins of ponds.  Pond Apple trees are sensitive to cold and South Florida is the northern limit of their range in the North America.  There was once a large forest of Pond Apples on the southern shore of Lake Okeechobee. This forest was lost with the coming of drainage canals and farms to that area.  Pond Apple trees are favored nest sites for many wading birds in Florida.  Wakodahatchee Wetlands in Palm Beach County has a large stand of Pond Apple trees that host nesting Wood Storks (Mycteria americana) and other impressive waders.  

Wood Storks (Mycteria americana) 
 nesting in a Pond Apple tree (Annona glabra).
Wakodahatchee Wetlands, Palm Beach County, Florida.  

Pond Apple trees produce pale flowers in spring.  The flower develops into the apple that grows throughout the summer, changing from green to yellow.  The apples are 3-4 inches in diameter and look very much like the apples we eat.    

Pond Apple (Annona glabra) flower bud.
Wakodahatchee Wetlands, Palm Beach County, Florida.

A young Pond Apple.
Wakodahatchee Wetlands, Florida. 

When ripe, the apples fall from the tree, often into water where they float.  The main way Pond Apple disperses it seeds is with its floating fruits.  The fruit can float for weeks and the seeds can even survive salt water immersion.  Pond Apples fruits probably floated across the Atlantic from South America to colonize Africa.

Mature Pond Apple fruit.
Wakodahatchee Wetlands, Palm Beach County, Florida.

Pond Apple fruits are edible, with yellow flesh and a mild taste.  But the seeds are poisonous and their extracts were used as a fish poison by Native Americans. Pond Apple is important in traditional medicine and has been used to treat a variety of aliments including tubercular cough, intestinal worms and diarrhea.

American Alligator (Alligator mississippiensis).
This gator is hunting Pond Apples.
Green Cay Wetlands, Palm Beach County, Florida. 

American Alligators relish these fruits and another name for Pond Apple is Alligator Apple.  On a recent visit to Florida, we saw a Florida Red-bellied Cooter (Pseudemys nelsoni) eating a floating apple.  The turtle would push the fruit around until it was trapped by vegetation, then take a bite.  We also saw a pack of Green Iguanas (Iguana iguana) eating a Pond Apple that fell onto dry land.  I am not sure how these reptiles handle the toxic seeds but they were not spitting them out.    

 

Florida Red-bellied Cooter (Pseudemys nelsoni)
eating a floating Pond Apple. 
Wakodahatchee Wetlands, Palm Beach County, Florida. 

             

Video of a Florida Red-bellied Cooter eating a Pond Apple.

Wakodahatchee Wetlands, Palm Beach County, Florida. 

Green Iguanas feasting on a Pond Apple.
Wakodahatchee Wetlands, Palm Beach County, Florida.

Pond Apples thrive in south Florida and other tropical areas.  The fruits and the trees are salt tolerant so they are better equipped than many plants for climate change induced sea-level rise.  Pond Apples will continue thrive in Florida and feed the reptiles. 

Passionflowers

 

Flower of Passiflora incarnata, the Purple Passionflower.
Rowan County, North Carolina. 

Passionflower flowers are as beautiful as they are complex.  They are classified in the genus Passiflora, a group of plants found mainly in the neotropics which is home for more than 500 species of passionflowers.  Two passionflowers are found in the Southeastern United States, Purple Passionflower, Passiflora incarnata and Yellow Passionflower, Passiflora lutea. 

The flowers have five sepals and five petals that are similar in shape and color.  Above the sepals and petals is a ring of long filaments called the corona. Arching from the center of the flower over the corona are five, pollen producing, stamens.  Then above the stamens are the carpels with three stigmas, the female flower parts that receive pollen. 

This striking flower structure caught the attention of early Spanish missionaries in the New World.  To these holy men, the flower was telling the story of the passion of Jesus. The five sepals and petals represented the ten faithful disciples.  Judas was left out for betraying Jesus and St. Peter; the founder of the Catholic Church, was not represented by a sepal or a petal because he denied Jesus on the night of his arrest.  The corona of filaments stood for the crown of thorns, the five stamens for Jesus's wounds on the cross and the three stigmas represented the three nails used in the crucifixion.  This religious interpretation of floral structure is how the plants got their name. 

Flower bud of Purple Passionflower.
Rowan County, North Carolina.

Purple Passionflower bud opening.
Rowan County, North Carolina. 

Purple Passionflower bud as it opens showing sepals,
petals and filaments of the corona. 
Rowan County, North Carolina. 

        

Fully open Purple Passionflower.
Rowan County, North Carolina.

Passiflora incarnata, the Purple Passionflower, is an herbaceous vine with three-lobed leaves.  The plant can ramble across the ground and produce tendrils that allow it to grow over other plants.  As its name suggests, the flower has purple sepals and petals.  The filaments are banded with purple and white while the stamens and carpels are yellow-green.  Passionflowers are pollinated by bees and develop large, green edible fruits.   

Three-lobed leaf of Purple Passionflower.
Rowan County, North Carolina. 

A Carpenter Bee (Xylocopa sp.) pollinating Purple Passionflower. 
The bee is collecting nectar as a stamen of the flower
 is depositing pollen on its back. 
Rowan County, North Carolina.

Two Purple Passionflower fruits. 
Rowan County, North Carolina. 

Yellow Passionflower (Passiflora lutea) is the second species in our area. Like Purple Passionflower, Yellow Passionflower is also a vine and its leaves have three lobes.  Yellow Passionflower is not as showy as the Purple Passionflower and has small yellow flowers.  But these flowers have the same complex structures as Purple Passionflower.  

Yellow Passionflower (Passiflora lutea) with its
rounded, three-lobed leaves and small yellow flower.
Rowan County, North Carolina. 

Yellow Passionflower has the same flower structure as its
more colorful relative, the Purple Passionflower.
Rowan County, North Carolina. 

Passionflower is the host of Gulf Fritillary butterflies (Agraulis vanillae).  These beautiful butterflies lay their eggs on the leaves of Passionflowers.  The eggs hatch and the larvae eat the leaves and transform into a chrysalis that hangs on the stems.  After a few weeks the adult butterfly emerges and feeds on the nectar of many plant species.  The bright orange color of the Gulf Fritillary is advertising its unpalatability.  Predators avoid this butterfly because it contains noxious chemicals that the larvae collected while eating Passionflower leaves.  Even the caterpillars of Gulf Fritillary advertise their toxicity with their bright orange color and black spikes. 

Gulf Fritillary (Agraulis vanillae) caterpillar on Purple Passionflower.
Rowan County, North Carolina. 

Passionflowers thrive in the hottest summer months. Even in the midst of a drought they bring on the those great flowers. So while many plants are riding out the heat, passionflowers put on their show.

Adult Gulf Fritillary.
Rowan County, North Carolina. 

A Count of Butterflies

 

A Gulf Fritillary (Agraulis vanillae) perched on Verbena brasiliensis.
Mecklenburg County, North Carolina. 

A day in high summer was set aside to count butterflies.  This count took place north of Charlotte, North Carolina, in forests and fields, near ponds and in powerline rights-of-way.   Thirteen people in six groups spent one day identifying and counting every butterfly they saw.  The count was conducted under the auspices of the North American Butterfly Association, a group whose mission is butterfly conservation. 

Junonia coenia, the Common Buckeye.
Mecklenburg County, North Carolina. 

Our little group consisted of Ron Clark, a master birder and butterfly whiz, Diane and me.  We did not start at sunrise like on a bird count, but at the civilized hour of 10 am.  Butterflies are exothermic and need the sun to raise their body temperature before they can fly.  Our day began in a meadow at Rural Hill, an historic farm in north Mecklenburg County.  We immediately began to see lots of Common Buckeyes (Junonia coenia).  These medium sized butterflies are marked with marvelous eyespots on the wings.  A single Monarch (Danaus plexippus) flew past seeking milkweeds.  

Monarch (Danaus plexippus).
Mecklenburg County, North Carolina.

Our second stop was Holly Bend, with its 18^th century house and grounds.  There we began to see forest and edge haunting butterflies including Eastern Tiger Swallowtails (Papilio glaucus), Hackberry Emperors (Asterocampa celtis) and Carolina Satyrs (Hermeuptychia sosybius).  

Hackberry Emperor (Astreocampa celtis).  This butterfly was
drinking sap on the truck of an oak (Quercus sp.)
Mecklenburg County, North Carolina. 

Carolina Satyr (Hermeuptychia sosybius).
Mecklenburg County, North Carolina. 

We found a couple of exquisite, tiny butterflies here; the Gray Hairstreak (Strymon melinus) and Eastern Tailed Blue (Cupido comyntas).  Both these butterflies have tails at the rear edge of the wings that look like antennae.  They also have eye spots on their hindwings.  The fake eyes and antennae makes it appear the head of the butterfly is at the back. This deception extends to the tails moving like antennae when the butterfly moves its wings.  The tails and eye spots trick predators into attacking the back edge of the wing while the butterfly escapes.  

Strymon melinus, Gray Hairstreak showing its antenna-like hairs and eyespots.
Mecklenburg County, North Carolina. 

Eastern Tailed Blue (Cupido comyntas) another butterfly with tails and eyespots. 
Mecklenburg County, North Carolina. 

After lunch at Lancaster’s Bar-B-Que we tackled Cowan’s Ford Wildlife Refuge.  This 650-acre sanctuary is located in a bend of the Catawba River and has a variety of habitats.  As we walked through a forested area, we found the uncommon Gemmed Satyr (Cyllopsis gemma).

Gemmed Satyr (Cyllopsis gemma).
Mecklenburg County, North Carolina. 

One of the most productive areas at Cowan’s Ford was in the powerline right-of-way.  Butterfly Weed (Asclepias tuberosa), sporting its orange flowers, was common here and were magnets for the butterflies.  It was here we started to see large numbers of Silver-spotted Skippers (Epargyreus clarus).  Skippers are an odd group of butterflies that are often hard to identify.  The Silver-spotted is the largest of the skippers and has easy to see white spots on the underside of the wings.  

Silver-spotted Skipper (Epargyreus clarus)
feeding on Verbena. 
Mecklenburg County, North Carolina. 

Gulf Fritillaries (Agraulis vanillae), one our most beautiful butterflies, were also in the powerline right-of-way.  From above Gulf Fritillaries are bright orange marked with black and white.  This contrasts with the underside of the wings that have multiple, brilliant silver spots.   

Gulf Fritillary.
Mecklenburg County, North Carolina. 

Another good butterfly under the powerline was the Pipevine Swallowtail (Battus philenor).  This large black butterfly has a patch of iridescent blue on the hind wings that flashes as it hovers.  Pipevine Swallowtails lay their eggs on Pipevines (Aristolochia sp.).  These plants contain toxic compounds that the caterpillars store and make the adult butterfly unpalatable to predators. This toxicity is the basis for a group of other butterfly species that mimic the Pipevine Swallowtail.  The mimics includes Black Swallowtail (Papilio polyxenes), the black form of the female Eastern Tiger Swallowtail, Spicebush Swallowtail (Papilio troilus) and Red-spotted Purple (Limenitis arthemis).  On the count day we saw all the species in this mimicry complex except the Black Swallowtail. 

Battus philenor, the Pipevine Swallowtail.  This toxic
butterfly is the model for a number of mimic species.
Mecklenburg County, North Carolina. 

Red-spotted Purple (Limenitis arthemis)
a mimic of the Pipevine Swallowtail. 
Mecklenburg County, North Carolina. 

We saw many colorful Sleepy Orange (Eurema nicippe) butterflies.  They are bright orange above and yellow below.  Its odd name comes from a mark on the forewing that looks like a closed eye.  

Sleepy Orange (Eurema nicippe).
Mecklenburg County, North Carolina. 

Another colorful little butterfly we saw was the Pearl Crescent (Phyciodes tharos).  It has a complex color pattern of orange and black.  This butterfly's name comes from the pearly crescent band along the rear edge of the wing.    

Pearl Crescent (Phyciodes tharos).
Mecklenburg County, North Carolina.

A patch of Verbena brasiliensis at the Cowan’s Ford parking lot delivered up large numbers of skippers including Delaware Skippers (Anatrytone logan) and Zabulon Skippers (Poanes zabulon).  

Delaware Skipper (Anatrytone logan).
Mecklenburg County, North Carolina. 

Zabulon Skipper (Poanes zabulon).
Mecklenburg County, North Carolina. 

We also spotted an American Lady (Vanessa virginiensis) in the Verbena stand. These colorful butterflies have a cob-web pattern on the underside of the wings and two large eye spots.  A related butterfly, the Painted Lady (Vanessa cardui) is also found in this area too but it has small eye spots on the wings. The saying goes, American Ladies have big eyes.   

American Lady (Vanessa virginiensis) with its big eyes.
Mecklenburg County, North Carolina. 

We had a great time spending a day with the butterflies but there was a more serious purpose to this endeavor.  Butterflies and other insects are sensitive indicators of environmental quality and change.  If butterfly numbers or species are in decline something is wrong in the environment.  Habitat loss, herbicide and insecticide use and climate change are all contributing to crashes in butterfly populations.  This year the migratory population of the iconic Monarch butterfly was placed on the endangered list.  The count in Mecklenburg County, North Carolina showed a slight decline in number of species reported over the last decade.  These results say trouble in on the way, or is already here.

 

 

Cloverleaf

 

Crimson Clover (Trifolium incarnatum) in a mountain meadow.  
Ashe County, North Carolina. 

Clovers (Trifolium sp.) are small herbaceous plants with a large impact; agriculturally, ecologically and culturally.  Trifolium is a member of family Fabaceae which includes peas, beans, vetches and acacias.  Clovers are usually low growing annuals and are native to all continents except Australia and Antarctica.  A defining characteristic of clovers is their three-part, compound leaves that give the genus its name. 

The leaves of clover play a major role in myth and legend.  Patrick, the patron saint of Ireland, is reputed to have used the three leaflets of clover to explain the Trinity to the pagan Irish he came to convert to Christianity.  However, clovers never appeared in St. Patrick’s writings so this story is probably apocryphal.  The ancient Irish word for clover was corrupted in English to give us shamrock. The association of shamrock/clover with St. Patrick led to its adoption as a symbol of Ireland.

I found a four-leaf and three leaf White Clover (Trifolium repens) in the same patch.  
Rowan County, North Carolina. 

Another interesting tradition is that four-leaf clovers are lucky.  Normally a clover has three leaflets but rarely a plant will make a leaf with four.   Since four-leaf clovers are rare, about 1 in 5000, finding one is considered good luck.  I think finding a four-leaf clover has more to do with persistence than luck.  

Roots of White Clover with root nodules containing
nitrogen fixing bacteria.
Rowan County, North Carolina. 

Clovers make small flowers grouped in compact heads.  They flower from early spring to late summer and are important nectar sources for a variety of bees.  Clover honey has a mild taste and is much in demand.  Clover plants have a high protein content.  Farmers grow it for silage and as a ground cover in crop rotation.  The large amount of protein in clover is a result of nitrogen fixing bacteria (Rhizobium sp) in the roots.  The bacteria invade the roots and induce the plant to make nodules where the Rhizobium converts nitrogen gas to amino acids.  The clover transfers organic nutrients to the bacteria in the nodule and the bacteria in turn provides amnio acids to the plant. Clover and its bacteria can add hundreds of pounds of nitrogen to an acre of soil during a season as a cover crop. 

Flowers of White Clover.
Ashe County, North Carolina.

Many of the species of Trifolium in the Southeast United States are native to Eurasia that have been become naturalized and now grow wild. Perhaps the most common clover in our area is White Clover (Trifolium repens).  This import from Europe is also called Dutch Clover and, of course, has white flowers.  The leaflets of this species often sport white, V-shaped marks.  

Red Clover (Trifolium pratense) in flower. 
Ashe County, North Carolina.

The flowers of Trifolium pratense, Red Clover, are not really red but rather a delicate pink.  Like White Clover, Red Clover leaflets can have V-shaped markings.  

Low Hop Clover (Trifolium dubium). 
Davidson County, North Carolina. 

Low Hop Clover, Trifolium dubium, is a low-growing clover with small yellow flowers.  This plant gets its name from the flowers that occur in heads that resemble the fruits of Hops (Humulus lupulus), an essential ingredient in beer. 

Rabbit Foot Clover (Trifolium arvense).
Rowan County, North Carolina. 

Rabbit Foot Clover (Trifolium arvense) has dense heads of rose-colored flowers.  The flowers have sepals that are tipped with long white hairs that give the plant a furry appearance and its name, Rabbit Foot.  Trifolium arvense thrives in dry, sandy soil, along roadsides and in what botanists call waste places.  

Crimson Clover.
Ashe County, North Carolina.  

Trifolium incarnatum, Crimson Clover, has the most stunning flowers of all the clovers in the Southeast.  They are bright crimson and are often found growing in large patches along highways and in meadows.   

A field of Crimson Clover.
Ashe County, North Carolina. 

All the clovers discussed so far were imported to North America, mostly to serve as cover crops or livestock feed.  There are two native clovers in North Carolina, both of which have limited ranges and small population sizes.  Carolina Clover (Trifolium carolinianum) is native to the Coastal Plain and is significantly rare.   Buffalo Clover (Trifolium stoloniferum) is an endangered species.  As its name suggests, Buffalo Clover was associated with eastern prairies and savannahs that were maintained by American Bison (Bison bison) herds. With the loss of these large herbivores in the east, the habitat for Buffalo Clover has diminished and it is now found in only a few locations.

Red Clover. 
Rowan County, North Carolina. 

Clovers come in a satisfying range of colors, shapes and sizes.  A meadow with clovers and abuzz with bees is a treat in springtime.  These humble plants fix nitrogen that reduces the need for fertilizer for crops.  Although most of the clovers we see in our area are introduced species, I am a fan.