Why Is the Bauhinia Tree Not Invasive ?

The Bauhinia tree (Bauhinia blakeana)(AKA Hong Kong Orchid tree) is a native of Asia. All Hong Kong orchid trees today are clones of the original tree planted in a garden in Hong Kong in 1880. It has been reproduced from cuttings ever since. Although they are one plant system they have not been susceptible to diseases.

Because the bloom is so attractive and had all of the anatomy to describe it as having flowers I could not see why it was sterile. The only option that I had was to inspect the organelles of the flower and see where the issue lie.

The feature image shows the flower with an obviously interested bee crawling inside.


Macro dissection

I started with an intact bloom and removed parts to expose the major anatomic features. This was followed by a separation of the components for microscopic examination.

Perhaps my favorite blossom from the neighborhood the blossoms simply cascade along the branches in progressive succession for months.

—-+—- Macro dissection

The Bauhenia flower has all of the required anatomy necessary for sexual reproduction. Septal, petals, stamen and carpel.


Micro dissection

Petal microstructure. No respiratory apparatus
Micro anatomy of typical leaf.
Filament with anther
Anther with pollen
Pollen from anther
Pollen grain detail
Macro image of stigma
Attempted fertilization by pollen into stigma
Macro through the Ova
Micro cross section through the ova which is void

Each of the separated components of the system were examined microscopically. This examination revealed that the area of the ova was without a defined structure. There were no ova and the core was a simple homogenous field without characteristics. It was barren. It does not reproduce sexually and therefore cannot produce seeds. Because it cannot produce seeds and reproduction is limited to propagation from cuttings it is not invasive. The same is true for Plumeria which is also propagated from cuttings. We have shown a similar method in a previous post on Propagation of Orchids by Division.

This posting is made in response to questions rising from the Power Point Presentation titled Flowering Trees of SWFL. a full listing of the trees can be found on this site. To find it GoTo the banner on the home page, from the menu select Findings and select the PDF document. There are associated reference links. You may print the list for your convenience.

#Bauhinia #Hong Kong Orchid tree #flower #anatomy #micro anatomy #reproduction #cuttings #propagation #barren #sterile # invasive # petal #septa #carpel #stamen #anther #pollen

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Wild Africa – A Trip In the Plan for 30 Years

An overview:

The previous posting on Africa showed the photographic preparation for the trip. This posting is an introduction to the upcoming blogs which will feature the animal and plant wildlife in more detail. This photo safari was planned for thirty years. It has been postponed three times. At last, this was the opportunity to go. Botswana and Kenya are the two countries we visited in sub-Saharan Africa. The reasons to go there were their diversity of wildlife, ecosystems, and safety. The month of August was selected to be timely to see the greatest density of animals in the most clement season. It was also an opportunity to look for the similarities and differences of the comparable African and US locations. Here are thoughts, impressions and recounting of the two weeks of experience there.

The title sunset image is typical of the African sky. The beautiful sunset red comes from sand and minerals of the desert suspended in the air and refracted by the light. These same sands which are blown across the Atlantic Ocean color our Floridian sunsets too.

This lengthy monologue is only a rudimentary description of a very large subject. It is intended to help understand and appreciate the reasons for these features seen on this expedition and to summarize the complexities of the climate, geology, the flow of water on the land, the interdependency of species and some similarities to areas in the USA. The two major eco systems were marshlands and savanna. In Botswana the wetlands of the Okavango delta were the focal point. In Kenya the savanna of the Maasai Mara section of the Serengeti was of greatest interest. The Okavango delta ecosystem has some similarities to the wetlands found in the Southwest Florida Everglades National and State Park systems. The Maasai Mara is more like the grasslands of Montana where, 250 years ago, buffalo, antelope, elk, and wolf roamed in their own great migration.

Climate and Geology:

The Okavango delta is 19 degrees south of the Equator. The Florida Everglades are 19 degrees north of the equator. They receive approximately the same amount of energy from the sun. The marshlands of the Okavango delta and the Florida Everglades are both essentially inland dispersions of fresh water. The Okavango is a unique feature of the Kalahari Desert. This delta is deep in the interior of the land mass and the climate is continental. Unlike the Everglades, it does not have the moderating exposure to a neighboring ocean. It has a soil basis of sand that averages 200 feet deep. On top of that is a soil of a few inches depth with mixtures of soil brought by wind, flood, and a thin organic compost. The average elevation is 3100 ft. The delta has three biome types that include savanna, woodlands, and swamp. The Okavango River supply is derived from the confluence of the Cubango and Cuito rivers in Angola. The annual flow reaches the delta between March and June with maximum flow in July. Additionally, there is seasonal 18-inch rainfall in the Okavango from November to February which adds to water shed. 

Floridian Everglades are at sea level and are founded on petrified sea bottom called sedimentary rock with a high calcium carbonate basis called limestone. The Florida Everglades topsoil is an average 17-foot-thick layer of marl (calcitic mud), peat and muck. The Everglades are subtropical wetlands whose freshwater system begins near Orlando in the Kissimmee River. The average annual rainfall is 60 inches. The Everglades have a maritime weather with tropical storms and moderation of climate. Climatically, there are no hurricanes in the Okavango and in the Everglades there is no drought.

In support of the science of plate tectonics. The Americas and Africa were one land mass 200 million years ago.

The concept of moving plates of the crust of the earth suggests that at a distant time in the past the assembly of the plates separated into the various land bodies. The shapes of the land mass fragments seen today can be manipulated as puzzle pieces into a larger land mass that fits together quite well. This particular assembly is called Pangea. If this is how the continents formed then there is a strong relationship between the eastern geology of the Americas and the western African geology. This fit is not entirely perfect, however, when considering the length of time for the division to transpire it is remarkably good. This has been supported by substantial evidence of rock formations that span the continents.The science is based on continental fit, matching rocks, fossils, corals, mountains, glacial striations, magnetic lineages and direct measurement of the movement.

Plate tectonics

Comparison of ecosystems:

Water and Land:

About 98% of the water that goes into the Okavango delta is eventually lost through evaporation and transpiration.  Transpiration results when water moves through the plant and evaporates from leaves and flowers. Despite the subtropical sun generating intense evaporation, the delta’s water is fresh, not salty. I was surprised by this because non circulating ponds of water in the middle parts of the islands have very high chemical and salt concentrations. This chemical concentration occurs in thousands of islands. The reason the water is fresh is that trees on the edges of the islands create a barrier of natural filters between the inner part of the islands and the floodplain. The second reason is a process of transpiration caused by trees. Water flows into the delta and carries with it silica and soluble minerals like sodium carbonate. As the water is lost from the trees, the silica and salts remain to build islands. The center of the islands concentrates the accumulated salt and as a result the vegetation dies from dehydration leaving a central bare white mineral spot. Termites facilitate island formation when they build nests of organic material, fungus, soil and water. These mounds of soil and nutrients promote tree and other plant growth.  When the seasonal water rises the termites build skyward forming islands. Eventually the nest is abandoned to form a new colony. The mound then collapses from animal invasion and erosion. Termites are the keystone species of the Okavango. Without them the delta would be like the desert. Water would be lost, and life would be less dense and less diverse.The Okavango has no palm trees and pines are also nearly absent. 

Pond in center of a large island in the Okavango delta. Salt has accumulated in the water causing the trees to dehydrate and die.
Okavango Savana, for centuries built from sedimentation and termite mound building. Trees in the center of the island died from dehydration caused by salt accumulation. Grass is a monocot and is salt tolerant. The termites moved out and the mound is vacant.
Intermittently flooded lowland in the high water season of the Okavango delta
Freely flowing fresh water in a branch of the Okavango river. The plant is Pampas grass (Miscanthus juncos).

The vegetation in Florida also plays an important role. The ocean barrier to salt invasion are mangroves which are salt tolerant. These mangroves are key to prevention of back flow of the salty ocean and hold the soil preventing erosion. Some fresh water flow does reach the ocean creating a relative partial positive pressure. The soils of the Everglades are rich in nitrates and farmers increase the nitrogen of a large portion of the Everglades. This has resulted in an overgrowth of a complex of bacteria species which feeds on the nitrates and deplete the nutrient value of the topsoil. The Everglades have no Acacia trees and lots of mosquitos.

The Kenyan savanna is climatically and geologically very different from the Okavango savanna. Kenya is at the Equator. It is a mile high in altitude and the soil is volcanic in origin. It is more like the area around Denver CO. It is surrounded by hills and mountains and has two rivers flowing through it. The major river flow is the Mara. The other is the Talek. It is part of the Mara-Serengeti ecosystem spanning Tanzania and Kenya and has been geologically very active with ancient and recent rock formations. It is in the Great Rift Valley. It is in this valley that the million-year-old petrified remains of very early hominoids have been found. 

High planes savanna of the Maasai Mara portion of the Serengeti plane. Mt Kenya is on the right horizon.
River cut into the Mara plane providing water to the vegetation and wildlife. This is a spot where the Wildebeests would cross during their migration. They would climb the banks of the river during a stampede. The animals are subject to the risks of death from the crocodiles that ply the river during the crossing.
Igneous rock formation on exposed hill side in the western Mt Kenya highlands.

The plants and animals are widely different in speciation in these three areas but they have similar behavior. This may be the result of adaptation to similar geologic and weather conditions. The apex predators of all locations are big cats. All have eagles, egrets, large carnivorous reptiles and cats and lots of grass.

Human impact:

The effect of the behavior of large numbers of modern people on the Florida ecosystem is dramatically different from the African locations. The Everglades water flow is highly engineered and not necessarily for the best. Southward flow of the Florida delta is interfered by highways and farms to the point that it does not meet the sea as it original did. The Okavango delta also does not meet the sea. In Africa the observed locations have relatively low populations and have been benignly neglected or protected from hunting, industrialization, mining or drilling and farming so that the plants and animals have survived basically unchanged for centuries or even millennia.

Romancing Wild Africa:

We went to see the animal life of Africa and did not go to see the cities, towns, or villages. We did not have much contact with the people of the areas we visited. Africa is a huge, populous, resource rich continent with a history that dates to the origin of most species. There is great wealth and great poverty. Too many people have nothing. They live an impoverished stone age existence in the space age. I acknowledge that many of these are desperately poor and politically persecuted to enslavement and/or death. The NGOs, like CARE, work to help many but must be careful to manage their limited resources. They also try not to support the migrant people in camps to a better level than the local people. The native residents also live by subsistence on gardening, raising a few cattle, contract farm working, tourism, and crafts. Some also engage in a variety of illegal endeavors such as poaching and grazing their animals on park land. You can read the newspapers for details of other antisocial behaviors such as intertribal warfare, abduction, extortion, theft, civil insurrection etc. Desperate people do desperate things.

The wilderness of the savanna of Africa is nothing like anything in eastern US. There is no sense of luxury to the plants or the soil. Much of the topsoil is sand deposited by wind and water. The stark beige color varies little by the source of volcanic mineralization. The organic content is not a rich loam of plant breakdown. It is thin and the organic content is from the sparse droppings from animals or the occasional bush or more rarely from a tree. Animal droppings are recycled by the life on the planes and provide an episodic line of trees from incompletely digested seeds. The brilliant emerald green plants, startling blue sky and the breathtaking color of twilight is such a relief from the monotony.


We will look in greater detail at the findings of this two-week photo expedition in the following blogs. They will focus more on species than locations. 

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#Africa #Okavango #Botswana #Kenya #Everglades #transpiration #Maasai Mara #salt #tectonics #transpiration #evaporation #Tanzania #marsh land #savanna

Tree Blooming Near the End of Summer

With this season we are nearing the completion of the annual cycle of the flowering trees before departing to Africa and Europe. We started this series in the first week of December of 2021 with Trees of Christmas. It has been a remarkable adventure to learn about and collect images and data for the flowering trees in South West Florida (SWFL). Nearly every hue and chroma of the rainbow has been represented in the flowers ranging from deep indigo to brilliant intense reds. See more details about them on our Epicollect5 website. The trees all have exotic origins from Europe, Africa, India and Central/South America. Perhaps we will find some similar trees in Botswana’s Okavango delta and the plaines of Kenya. If all goes as planned we will be there in August of this year.

The featured image is a Purple Glory.

Many of the Blooming Trees of Late Spring are still in flower and in part include the Royal Poinciana, Jacaranda, Plumeria, and the Mexican Tulip. Missing is the Bauhania which had been blooming since Christmas. It has, at last, given up the last flowers.

Royal Flamboyant Poinciana. Still one of my favorite flowering trees, it is repeatedly throwing out new blossoms and filling the neighborhood with a spectacular display of color.

Here are the last of the newly blooming trees which I found on my last walk about.

Pride of India (Langerstroemia Speciiosa). Native to South Eastern Asia including India.
Australian umbrella (Scheffera actinophylla). An evergreen tree native to Queensland Australia. Toxic to dogs and cats when eaten or touched by the sap.
Not as big as a standard tree the Princess flower tree is also known as Purple glory. It has some of the most intense purple flowers.
Purple glory (Pleroma semidacandrum) is native to Brazil.

All of these blossoms are found less frequently as the summer progresses. The neighborhoods and wilderness are definitely less colorful. The remaining flowers will probably last for two months. We will look again after returning from the safari. The interesting plants now include palms and pines. Next year adventures will focus on the palm trees more closely showing the varieties of colors, leaf patterns and fruiting bodies. We will finish the series by making the autumnal blossoms posting during the end of October.

After returning from Africa I hope to post a number of articles comparing the landscape, water features, plants and animals to those in SWFL. I expect these to be very interesting and hope that you are also interested.

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#summer #trees #cycle #blossoms

To Tree or Not to Tree

Is a palm tree not a tree? In categorizing plants and animals for the Everglades Ark Epicollect5 data base I was conflicted in assigning the characteristics of trees to palms. I have called them palm trees forever but they really look different from oak, olive or other trees. Checking out the definition of a tree resulted in an ambiguous answer.

Featured image: In a spin about palms

Definition of tree: From a technical standpoint, palms fit American Forests’ current definition of trees, as they are woody plants with an erect perennial stem or trunk, at least 9.5 inches in circumference at 4.5 feet above the ground. They also have a definitively formed crown of foliage and a height of at least 13 feet. 

This still didn’t satisfy my curiosity. I still wondered why they were so different. Here are photographs of tree aspects to show the physical differences:

Tree landscape view

Olive tree, rigid and arborized branches
standing adjacent to palm
Palm tipped by heavy wind storm

Leaf patterns

Central vein with alternating branched secondary veins
Radial symmetry of straight palm leaves with straight unbranching veins

Photomacrograph leaves

Here is a demonstration of reticular veining ~35X
All straight, parallel veining without branching ~35X

Photomicrograph of leaves

Branching veins becoming progressively smaller as they branch ~600X
Straight, parallel veins even at the microscopic level at ~800X

Common biology of both di and mono cotyledonous plants. Both have chloroplasts for metabolism and stoma

Stoma are more randomly disbursed in the leaf surface. The stoma are on the underside of the leaf in the dicot group ~800X
Xylem and phloem circulation and stoma for respiration. The stoma are on the upper side of the leaf ~800X

Tree roots

Broad and deep root system of dicotyledon, olive tree adjacent to monocotyledon palm.
Root ball of monocotyledon, palm exposed by erosion

Tree cross sections

Tree rings show annual growth and suggest weather conditions. Specialized bark system.
No rings and no mechanism to repair. Bark is a remnant of leaf system.

Tree behavior to injury

Progressive but not yet complete healing of dicot tree

There is no mechanism for healing in palm trees.


All dicots have five petals to their flowers

No petals but other monocots have three petals

Here is a list tabulating differences in the characteristics between the tree types.

Aspects:Palm True tree
Rootsshallow multiple small distributeddeep, branching with tap root
Trunkthe trunk is actually the stem which bendsthick, rigid
Branchesno branchesmultiple arborizations
Leavesveins begin at the base, run parallel to the length of the leaf, stoma on upper leaf surface central veins with multiple arborizations to leaf periphery, stoma on lower side of leaf
Outer surfacestumps of old growth leaves, no structured interior wood specialized bark covering wood
Trunk corefibrous without annular ringswoody, highly structured interior nutrient flow system
Interior structurefibrous with layered leavesorganized circulatory system, annular growth rings
Recoverycannot repair injury or diseasecan heal wound and fight disease
Comparison of plant distinguishing characteristics

A palm tree is really a palm grass.1 They are monocotyledons. Genetically they are similar to other grasses like bamboo. They are resistant to storm damage fracture because of their lack of a woody interior structure but are more subject to uprooting because of their shallow roots.

Grasses are flowering plants that are members of the monocot class that also include corn, rice, lilies, orchids and palms. Now that I understand what a palm is I can more freely post palm types, flowers and fruits. Later I will show the microscopic view of tree anatomy pointing out differences between monocots and dicots.

This subject opens a wide spectrum of ideas regarding plants. We have already broached the idea of cotyledons. There is much more to explore including the microscopic examination of cross sections of plants and their appendages or stems, roots and flowers as well as angiosperms vs gymnosperms and the role of sexual vs asexual reproduction and seed development.

The micrographs shown here are all done with simple direct bright field and transmitted light. Just wait until we get into cross sectional, stained, transmitted plane, and polarized light illumination!

The Epicollect5 database will be modified to reflect this altered view of classification.

  1. References:

Dicot vs monocot

Palm leaf anatomy

Plant vascular system

Plant leaf anatomy

#tree #palm #monocot #dicot #monocotyledon #dicotyledon #veins #stoma #annular rings #reticular veining #petals

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