Basal Angiosperms II

 I wrote earlier this year about a group of plants called basal angiosperms.  These are flowering plants that branched off the evolutionary line that led to the eudicots and monocots.  Basal angiosperms have some characteristics of both monocots, like flower parts in multiples of three, and eudicots, with net veined leaves. 

Waterlilies are basal angiosperms classified in the family Nyphaeacea and grow on all continents except Antarctica.  These familiar plants grow in lakes, ponds and slow-moving streams.  They have floating leaves and brightly colored flowers that emerge from the water.  The largest waterlily in the world is from South America.  This waterlily, Victoria amazonica, has leaves that are ten feet in diameter and can support the weight of a person.  A famous nineteenth century lithograph shows young Annie Paxton standing on a leaf of V. amazonica at the English estate Chatsworth.  Annie’s father, Joseph Paxton, was the head gardener at Chatsworth and the first to get V. amazonica to flower in England.  Paxton noted the ribbed supports on the underside of the leaves of V. amazonica and used these as inspiration to design a large greenhouse at Chatsworth.  Later Paxton became the lead architect of the Crystal Palace that housed the Great Exhibition of London in 1851. 

Annie Paxton standing on a Victoria amazonica leaf at the
English estate of Chatsworth in 1849.
https://en.wikipedia.org/wiki/Victoria_amazonica
 

We could not visit the Amazon Basin to see these lilies but Fairchild Tropical Botanic Garden in Miami, Florida has Victoria sp. growing in a pond.  The Miami Victorias are not as large as those growing in the Amazon but the Florida plants sport 2-3 foot leaves that have the characteristic upturned edges.

Victoria sp leaves at Fairchild Tropical Botanic Garden
Miami, Fl

Two common waterlilies in the Southeast are the alliterative Nymphaea and Nuphar.  One is Nymphaea odorata or the fragrant waterlily.  The scientific name of the fragrant waterlily is a wealth of information.  The genus Nymphaea gets its name from the nymphs of Greek mythology.  These minor female deities were associated with natural sites, particularly water.  The species name, odorata, tells that the flowers are fragrant and help attract its beetle pollinators. Fragrant waterlily leaves are large, bright green and oval shaped with deep cleft that runs to near the center of the leaf.  The flowers are white with dozens of petals and numerous stamens. 

Fragrant Waterlily (Nymphaea odorata) in Salisbury, NC

Nuphar advena, the yellow pond lily or spatterdock, has floating leaves and a yellow flower that emerges above the surface of the water.  The petals of the flower are inconspicuous while the sepals give the flower its yellow color.  Spatterdock is widely used in traditional medicine to treat diarrhea and skin disorders. 

Spatterdock (Nuphar advena) in Palm Beach County, FL 

 Magnolias are a large group of highly successful basal angiosperms.  The family Magnoliaceae contains more than 200 species and they are found in North, Central and South America as well as East Asia. Two important members of this family in the Southeastern United States are Tulip Poplars and Southern Magnolias. 

Liriodendron tulipifera goes by a number of names Tulip Poplar, Tulip Tree or Yellow Poplar and is among the tallest eastern trees.   Tulip Poplars in the Joyce Kilmer Memorial Forest in western North Carolina tower to heights of more than 160 feet with circumferences of greater than 20 feet.  Tulip Poplars are fast growing, long lived trees that are valuable for timber.  Tulip poplar leaves are large with four lobes and its yellow-green flowers are tulip-shaped.  The flowers have 3 sepals, 6 petals with orange at their bases and multiple stamens and carpels. 

Tulip Poplar (Lirodendron
tulipfera) flowering in April, Salisbury, NC
The flowers are shaped like tulips.

Close up of Tulip Poplar flowers showing six petals, numerous stamens and carpels.

Southern Magnolia, Magnolia grandiflora, is a forest tree with large shiny green leaves and in late spring produces large, white, fragrant flowers.  One of the primitive characteristics of magnolias is their stamens and carpels are arranged in a spiral pattern rather than a whorl.  As the petals fall from the flower the spiral-pattern of stamen scars are apparent.   The carpels that produce the seeds are in a cone that also has a spiral pattern. 

Bud of Southern Magnolia (Magnolia
grandiflora) in Salisbury, NC

Flower of Southern Magnolia with multiple petals. 

Mature flower of Southern Magnolia.  It has multiple petals, many stamens
some of which have fallen on one of the petals and numerous carpels, 

Details of a Southern Magnolia flower.  Petals are inserted at the bottom of the flower.
Next come the yellow stamens and at the top are the many carpels that will produce seeds. 

A dying Southern Magnolia flower.  In the center is the carpel that will develop into
the seed bearing cone.  The purple column below the carpels has the spirally arranged
purple scars where the stamens were attached. 

An immature cone of Southern Magnolia
with its carpels and a few stamens
still attached.

Southern Magnolia cone.  Below the cone are
scars from the stamens and below them
are the spiral scars of the petals.

A nearly ripe cone of Southern Magnolia.  Seeds are developing
inside the cone.

A mature cone of Southern Magnolia.  The bright red seeds
are being released. 

By early fall, the cones split and show bright red seeds.  The seeds remain attached for a time attached to the cone by strong, silky threads that smell, oddly enough, like Juicy Fruit gum.  

Mature cone of Southern Magnolia with red seeds.

Southern Magnolia seeds are attached to the cone by threads
that smell like Juicy Fruit gum. 

These basal angiosperms are relics of deep time.  They remind us of a world long past.  So next time you see a magnolia or a water lily or a pawpaw, think dinosaurs. 

What Good is a Ragweed?

Ragweed is notorious for causing seasonal allergies. In late summer and early fall an estimated 23 million Americans suffer runny noses, itchy eyes and respiratory congestion caused by pollen of ragweed.  This seasonal allergy, also called hay fever, is caused by an inappropriate immune response.  Our immune system identifies and eliminates foreign material like an infectious bacterium or an invading virus.  In some cases, the immune system mounts a strong attack on a non-pathogenic agent like ragweed pollen.  This overly vigorous response includes the release of a powerful molecule called histamine that causes many of the hay fever symptoms mentioned above.  Treatments for seasonal allergy usually contain an anti-histamine to counter the effects of histamine.  

Giant Ragweed Ambrosia trifida 

But ragweed has a life of its own, beyond being the cause of seasonal allergy, and an interesting life it is.   Two species of ragweed are common in North Carolina, Common Ragweed (Ambrosia artemisiifolia) and Giant Ragweed (Ambrosia trifida).  These two ragweed species are in the same family as sunflowers, the Asteraceae.  The name of the genus of ragweed, Ambrosia, is from the Greek and means food of the gods.  Ragweed seeds are highly nutritious, containing high concentrations of protein and oil.  Native Americans grew ragweed as a food crop then abandoned its cultivation when they adopted corn based agriculture.  The specific name of Common Ragweed, artemisiifolia, suggests the leaves of this plant resembles the highly dissected leaves of Artemisia, wormwood or sagebrush.   The specific name of Giant Ragweed is trifida and that refers to the three-lobed leaves of the plant. 

Common Ragweed grows to a height of about 2 feet.  It has dissected leaves and produces small, green flowers.  The flowers, which do not look like sunflowers despite being in that family, are borne on vertical, candelabra-like inflorescences.  Each inflorescence has dozens of male flowers that bear pollen-producing stamens.  Near the base of the inflorescence are a few female flowers that have the egg-producing carpel.  The flowers of ragweed are small, inconspicuous and colored green.  Plants that have brightly colored flowers use them to attract pollinators like insects or birds.  Ragweed does not depend on animal pollinators but uses wind to spread its pollen. Wind pollinated plants tend to have dull flowers.  Each ragweed plant produces about a billion tiny pollen grains in a season.  This pollen floats on the wind and a few grains pollinate female flowers.  This strategy of producing lots of pollen and casting it to the winds contributes to ragweed’s importance as an allergy health hazard because some of that pollen is inhaled by sensitive people.  Imagine billions of plants each producing a billion pollen grains and you can see the impact of this plant on human health. Each ragweed plant has a few female flowers at the base of each inflorescence where they receive the free-floating pollen.  Pollen lands on stigmas extending from the female flower and a pollen tube grows down into the flower to fertilize the egg within.  Each flower makes a single, dark brown seed that is a favored food of wildlife including quail.  

The dissected leaves of Common
Ragweed, Ambrosia artemisiifolia

Male, pollen producing flowers
of Common Ragweed

Female flowers of Common Ragweed
with their extended stigmas to collect pollen

Giant Ragweed is much taller than Common Ragweed with plants reaching 13 feet in height.  The stems bear the large, three-part leaves that give the plant its scientific name.  At the tops of stems are the inflorescences that are similar to those of Common Ragweed.  The green flowers, both male and female, carry out the same type of reproduction as the Common Ragweed with massive amounts of pollen released and brown seeds produced. 

The three-part leaf of Giant Ragweed, Ambrosia trifida

Male flowers of Giant Ragweed with yellow,
pollen bearing stamens visible.  

Female flowers of Giant Ragweed with their
stigmas extended.

 Brown fruits developing from the female flowers of Giant Ragweed.

Ragweed plants produce large amounts of pollen because wind pollination is inefficient.  Other wind-pollinated plants, like Bermuda Grass and Oaks, also produce vast numbers of pollen grains and contribute hay fever suffering.  Ragweed pollen has a molecule on its surface that makes it a potent allergen that stimulates the human immune system.  The molecule is a protein, an enzyme called pectinase.  This enzyme breaks down pectin, a complex carbohydrate called pectin found in plant cell walls.   Pectinase helps the pollen deliver the sperm nucleus to the egg, allowing fertilization and more ragweed for next year.  Remember, ragweed is not trying to make us miserable, it is not trying to give us runny noses, it is not trying to clog our sinuses.  But, in the fall of the year these things do happen because of the reproductive strategy followed by Ambrosia artemisiifolia and Ambrosia trifida. 

Back to the question, what good is a ragweed?  People often ask this question of living things they view as problems.  What good is a mosquito?  What good is a tick?  What good is a ragweed?  All these organisms had an evolutionary history before people appeared on the scene.  They lived, reproduced and adapted.  The two ragweed species in this area are highly successful.  Ambrosia artemisiifolia and Ambrosia trifida fix carbon, provide food for a variety of animals, were once crop plants and because of the shape of a protein on the surface of their pollen, cause allergies.   None of these traits was the result of design for a human, utilitarian end. With the gene editing technology CRISPR it is now theoretically possible to deliberately cause the extinction of a whole species.  This very thing, intentional extinction, has been discussed to rid the world of a species of a mosquito that transmits one type of malaria.  I hope humanity has better sense than to eliminate even more species than we have already done, be it the vector for a terrible disease or the cause of hay fever.  

Fairy Rings

A perfect circle of mushrooms.  They pop up after a rain in summer or fall.  A fairy ring.  The name suggests magic and there is a deal of biological magic taking place.  There are several fairy rings in our suburban neighborhood in North Carolina.  The one we see the most is a ring of the poisonous mushroom Chlorophyllum molybdites. This fairy ring starts with a single, microscopic spore of the fungus landing in the soil.  This spore germinates and sends out hyphae, microscopic threads of cells, that absorb nutrients from the soil.  The hyphae grow out symmetrically in all directions making a circular colony fungus. As the colony gets larger the older part in the center dies and the living portion is along the perimeter of the colony.  When the moisture and temperature conditions are right, the hyphae on the circumference send up mushrooms in a ring.  The mushrooms carry out sexual reproduction and release more spores.  These spores float through the air and if they land on a favorable patch of ground, a new fungal colony can form.    

A fairy ring of Chlorophyllum molybdites on a lawn in Salisbury, NC. 

Chlorophyllum molybdites makes a large white mushroom.  The stalk of the mushroom has a distinctive ring just below the cap.  The mushroom’s cap has off-white scales on the top and spore producing gills on the bottom.  One of the unique features of Chlorophyllum molybdites is it makes green spores.  The spores give the gills a pale green color too.  Spore prints are a good way to see the color of fungal spores.  To make a spore print you remove the stalk from the mushroom, lay it on a piece of paper, cover it with a bowl and wait 24 hours.  The spores are released and fall straight down onto the paper making an exact print of the gills and showing the color of the spores too. 

A single mushroom of Chlorophyllum molybdites just emerged from a lawn.

Two Chlorophyllum molybdites mushrooms with scales on the cap. 

The underside of the cap of Chlorophyllum molybdites showing the ring on the stalk,

A closeup of the gills of Chlorophyllum molybdites with the green color.

Spore print of Chlorophyllum molybdites.  The spores make an exact impression
of the gills and show the spore color.

Chlorophyllum molybdites has several common names.  The most interesting is vomiter from the consequence of ingesting this poisonous mushroom.  Chlorophyllum molybdites causes most of the mushroom poisoning cases in the United States.  A person unlucky enough to eat Chlorophyllum molybdites experiences gastrointestinal distress.  It starts with cramps, then vomiting and diarrhea, sometimes-bloody diarrhea.   Chlorophyllum poisoning is almost never fatal and the symptoms clear up in a couple of uncomfortable days. 

Fairy ring season is upon us.  Enjoy the magic but don’t eat the mushrooms. 

Moth Mimic

You can see these moths, these hummingbird moths, all summer.  They hover, move from flower to flower and sip nectar.  They are unusual for moths because they fly during the day time.  This group of moths has a bewildering number of names: hummingbird moth, hawk moth, bumblebee moth, sphinx moth.  With a casual glance these moths can be mistaken for a hummingbird or a bee and that mistaken identity gives them a couple of their common names.  There are three species of hummingbird moths in Eastern North America.  This summer we hosted a group of Hemaris diffinis. These moths fed on beebalm, milkweed, lantana and other flowers in our yard. 

 

The hummingbird moth Hemaris diffinis feeding on Lantana camara in North Carolina

Hemaris diffinis, besides being called all these other names has yet another common name, snowberry clearwing.  Snowberry (Symphoricarpos) is a member of the honeysuckle family and Hemaris diffinis uses this plant as a host for its eggs and larvae.  The clearwing part of the name comes from the transparent areas on the moth’s wings.  Hemaris diffinis has a large body with a golden thorax and a black abdomen.  This yellow and black pattern is like that of several species of bumblebees.  At the tip of the abdomen, this hummingbird moth has a fan of bristles that resemble the tail of a hummingbird.  Hemaris diffinis does not flap as fast as a hummingbird but the clear areas of the wings make them appear to be a blur, just like the wings of a hummingbird.  Hemaris diffinis has an extendible mouthpart, called the proboscis, which it uses to sip nectar from flowers.  The proboscis even resembles the beak of a hummingbird.  

The video above shows Hermaris diffinis, with its yellow body and black abdomen, hovering as it feeds on Lantana.  This is similar to the color pattern of the Common Bumblebee Bombus impatiens in the next section of the video.  Finally a male Ruby-throated Hummingbird perched on and hovering near a hummingbird feeder shows a similar flight and feeding pattern to the moth. 

Hemaris diffinis is a mimic and it is mimicking both hummingbirds and large bees.  The question is, why?  It is easy to explain mimicking a bee.  Bees are able to sting and they advertise this fact by bold patterns and colors of yellow and black.  This yellow and black pattern is a well know warning to potential predators.  A number of insects including flies and beetles mimic bees and enjoy protection from bird predators.  But why would a moth mimic a hummingbird?   The birds that prey on moths do not hunt hummingbirds, so being mistaken for a hummingbird is a second level of protection. 

Summer is still going and the hummingbird moths are still flying.  Go out and enjoy these double mimics in fields and gardens. 

The (Metaphorical) Big Fish

This post is not really about fish but it is inspired by anglers.  Fishermen and women have stories and the best stories are about fish that got away.  As these stories are told and retold the fish get bigger, they fight harder and they leap more dramatically.  Taking photos of animals is kind of like fishing because lots of times the big ones get away.  Here are some of the ones that got away from me photographically. 

This White-tailed Deer (Odocoileus virginianus) saw me bring up the camera and it sprung away.

A Cooper's hawk (Accipiter cooperi) was perched near the Salisbury, NC Greenway.  As I tried to take a picture the hawk flew toward me with a glare in its eyes.

This large blue dragonfly, an Eastern Pondhawk (Erythemis simplicicollis) was using a twig for a perch.  This is the Eastern Pondhawk leaving the perch.

A male Ruby-throated Hummingbird (Archilochus colubris) escaped from focus at a feeder in our yard. 

A juvenile Five-lined Skink (Eumeces fasicatus)was climbing fast up the wall of our house and ran out of the frame.

This male Summer Tanager (Piranga rubra) was perched in a scrubby tree on a Piedmont Prairie in Mecklenburg County, NC.  Then it flew.

I was in a swamp in Rowan County, NC trying to get the definitive picture of a Prothonotary Warbler (Protonotaria citrea) .  This male jumped at the wrong moment.  

This Pied-billed Grebe (Podilymbus podiceps) was feeding in a pond in Palm Beach County, FL when it took a dive.

I was photographing Gray Squirrels (Sciurus carolinensis) in Spencer, NC when this one bounded away.

A Red-shouldered Hawk (Buteo lineatus) was hunting along a creek in Clayton County, GA when it decided I was too close and flew away. 

A Monarch Butterfly (Danaus plexippus) departs from a Tropical Milkweed (Ascelpias curassavica) in Salisbury, NC.

Driving through Florida's Merritt Island National Wildlife Refuge on a September afternoon, Diane and I could not believe our luck.  Two Peregrine Falcons (Falco peregrinus) were roosting in the same dead pine.  When we got close enough to take a picture, a Turkey Vulture (Cathartes aura) decided to land in the same tree.  You can see one Peregrine still at the top of the tree and the other Peregrine, which was displaced by the Vulture is just coming out from behind the tree on the left.  The Vulture is landing in the middle. 

We took a boat this summer in Alaska and the captain had posted a sign that said, "There are no bad birds".  I try to say, "There are no bad pictures", but I am not so sure.

A Blue Green Snake

Rough green snakes, Opheodrys aestivus, are common in the southeast.  These small snakes are bright green on their backs and sides with a yellowish-white belly.  They are among the most arboreal of the snakes in this region, climbing through the branches of trees and shrubs where they hunt insects and other invertebrates.  The largest rough green snake might be two feet in length.  They are called rough because their scales have a ridge running down the middle (the keel) that gives them a rough feel when handled.  These snakes are good-natured and don’t bite if you pick them up to see how rough they are. 

Rough green snake (Opheodrys aestivus) showing its bright green color

Diane and I regularly see rough green snakes while walking the local greenway.  They are hard to see when they climb in the vegetation because their green color is the perfect camouflage.  These snakes often cross the paved greenway trail and that is where we can get good looks.  Recently we found a dead rough green snake, killed by a car, on the side of the road at greenway’s end.  The funny thing was, this green snake was partially blue in color.  It turns out that rough green snakes turn blue when they die.  The reason they turn blue after expiring gets into the mystery of color.

Vertebrates have a hard time making themselves green.  Unlike plants that make the green chlorophyll pigment to run photosynthesis, green snakes, lizards and birds must use two different means to turn green.  Their green color is usually a combination of yellow from a carotenoid pigment and blue produced from the structural elements of their skin or feathers.  This combination of pigment color and structural color works for green snakes, green lizards and green birds. 

Pigments molecules absorb certain wavelengths of light and that gives them their color.  Chlorophyll can be extracted from plants and still retain the green color.  Structural color is different.  It depends on the physical arrangement of small particles that refract certain wavelengths of light to produce color.  In many cases with structural color in animals, you need to view the subject from a certain angle for the color to be revealed. Eastern Bluebirds appear blue because tiny granules in their feathers refract blue light to the viewer.  In some light conditions bluebirds will appear black because the refraction does not occur.  Ruby-throated Hummingbird throats may appear dull from one angle, but as the bird turns a brilliant flash of red will shine out.  You cannot extract blue pigments from the feathers of bluebirds and you cannot extract red pigments from the throat feathers of hummingbirds.  Both these are examples of structural color.  

Rough green snakes have cells in their skin that contain a crystalline arrays of guanine, one of the components of nucleic acids.  The arrangement of the guanine crystals in these cells refract blue light.  Also in the skin of rough green snakes are cells that have yellow pigments that reflect yellow light.  Just like in an elementary school art class, yellow plus blue gives green. 

 

Dead rough green snake (Opheodrys aestivus)  with green regions and blue regions.

When a rough green snake dies, the yellow pigment begins to break down. The blue refracting crystals are more stable so the dead green snake gradually turns blue as the yellow pigment is degraded.  This was the state of the dead snake we found.  In some parts of its body the yellow pigment remained so it looked green in others the yellow pigment was lost and only the blue shone through. 

Alaska Connections

Diane and I recently made a twelve day trip to Alaska with a group of birders from North Carolina and Virginia.  On this trip we would revisit places from our expedition of 31 years ago and go to some new ones.  We saw lots of new land- and seascapes, a Canada lynx and a walrus, a Gyrfalcon and Bristle-thighed Curlews.  We also ran into some plants and plant-ish things I have written about recently in this blog.

Last month I wrote about alders growing near my home.  In Alaska, at Summit Lake on the Kenai Peninsula, the alders were in flower.  Alders in North Carolina flowered in early March but in southern Alaska, June is the flowering season.   The alder we saw in at Summit Lake was Alnus viridis ssp sinuata, the Sitka alder.  This alder is a scrubby tree and grows throughout Alaska, across the Bering Strait into East Asia, along the west coast of North American into northern California and down to the northern Rocky Mountains. The Sitka alder’s leaves are bright green with serrated margins.  The female catkins were green and the male catkins were brown, had already released their pollen but were still on the plant.  Sitka alder is an early colonizer of new land, beginning primary succession.  With global climate change, glaciers are receding at an increased rate.  When the retreating glaciers leave exposed ground, Sitka alders become established.  Their nitrogen-fixing, symbiotic bacteria enrich the soil paving the way for new forest to grow where the glaciers disappeared. 

Sitka alder (Alnus virdis ssp. sinuata)
with catkins of male flowers.

Sitka alder (Alnus viridis ssp. sinuata)
with female catkins

Haircap moss (Polytrichum strictum) gametophytes

The moist forests on the south side of the Alaska Range support a wide variety of mosses.  I wrote about North Carolina mosses  in April.  In Denali State Park we found thick and beautiful stands of Polytrichum strictum, the haircap moss.  This moss has a circumpolar distribution and extends into the lower 48 US states.  Clusters of gametophyte plants produce a green, star-pattern.  The sporophytes, the result of moss sex, have a little hairy cap at their tops, covering the capsule where the spores are waiting to be released. 

Haircap moss (Polytrichum stgrictum) gametophyes
with sporophytes

Kamchatka rhododendron (Rhododendron camtschaticum)
flowering on the tundra

Back in January I posted about lichens in Florida and North Carolina.  Out on the tundra of Denali National Park, where willows are inches tall and tiny rhododendrons (Rhododendron camtschaticum) produce large flowers, we found several species of lichens including the famous reindeer moss.  Reindeer moss is, of course, not a moss but a lichen, that symbiotic organism made of a fungus and an alga.  The lichens pictured here are Cladonia rangiferina (gray reindeer moss) and Cladonia fimbriata (trumpet lichen).  Lichens form much of the diet of caribou, Rangifer tarandus who endlessly graze as they walk the tundra.  Caribou are the same species as the old-world reindeer but have never been domesticated.  These large herbivores can find lichens even in winter.  Caribou use their sharp hooves to expose the lichens below the snow.  Unfortunately we did not see any caribou grazing the lichens of the tundra.   

Reindeer moss, the lichen
Cladonia rangiferina

 

Trumpet lichen Cladonia fimbrata

The differences between the Southeastern US and Alaska are striking.  There is a transition from subtropical to arctic with different habitats, climates, plants and animals. These areas are separated by a distance of more than 3000 miles and 30 degrees of latitude.  But the similarities between the Southeast and Alaska are profound.  Linked by biogeography and the evolutionary history of the inhabitants, the similarities were as striking as the differences.