Chysanthemum coronarium

Chysanthemum coronarium

Aside from being beautiful to look at, plant is interesting from various points of view. To begin with I had a single plant in my yard about 15 years ago. In spite of the fact that this species is an annual, this particular plant lived in my garden under ideal conditions through the 2nd year. Although reported as an annual it flowered profusely throughout 2 consecutive summers, but no viable seed was produced, suggesting the need for out-crossing. It is self sterile and needs pollen from another plant.

C. coronarium is in the Asteraceae family and the Anthemidea tribe.  It has highly dissected leaves and forms capitula typical of the Sunflower family with both ray and disk flowers. The stems and the leaves have a pungent odor.  The seeds, unlike those of  other sunflowers, lack a pappus, or the airborne part of the seed, as in a dandelion.


C. coronarium is also know as the Chrysanthemum greens because it's stems and leaves are edible.  It is native to the  Mediterranean and East Asia where it is widely available and frequently used in cooking. It is reported to have high nutritional value especially with high levels of carotene and potassium.

To my knowledge, or at least during the time that I was investigating this plant many years back, C. Coronarium is infrequently found in Riverside. However, it is widely found in disturbed, vacant areas in San Diego where the environment is more conducive.  In areas in coastal San Diego, where this plant is sparse initially, such as in vacant lots, it may grow to dominate in just a few years.

Roots:Underground and Overlooked

Unbranched roots of a leek (monocot)

All roots are not created equal. A general definition of a root is a part of the plant body that bears no leaves and therefore no nodes. There are two basic types of root systems, tap root systems and fibrous root systems.  Tap root systems develop a primary root that gives off lateral roots. The main tap roots anchor the plants to the ground and have the ability to reach water that is locked deep in the soil giving them an advantage in drought conditions. Tap root systems can occur only in dicots. Fibrous root systems are made of clusters of thin fiber like roots that are shallow and spread horizontally. They are unable to provide the stability that tap roots provide. Fibrous root systems occur in monocots but also common in dicots.

The roots of an onion are an example of a fibrous root system.  Solanum mauritianum is another plant that has a very conspicuous and well defined fibrous root system.  Ambrosia acanthocarpa is a native southern California plant that has a well developed tap root system.  Because of it's deep and well developed tap root, it is often still green when everything else is dried up in late summer. While there gradations many plants will fall into one of these two categories possessing either a tap root or fibrous root system.

The roots of angiosperms(flowering plants) can be differentiated with little effort between monocots and dicots. Monocot roots do not fork but continue out in a more or less straight direction until they terminate growth. The diameter of the root that is first established by the root cap is the permanent diameter in monocots. If they expand in diameter it is very little, if at all. A classic example of monocot roots can be seen in the onion where all the roots are the same diameter. As compared to monocots, the roots of dicots can grow continuously in diameter and length, taking on the classic look of tree roots. In dicots, root branching can occur anywhere and form new roots.

Dicots have root systems that can range from having very fibrous roots, as seen in marigolds, to having very deep taproots, as seen in pecan and mesquite trees and alfalfa. The word phreatophyte is often used to describe plants which have very deep taproots that are able to reach deep into the ground to absorb water in the phreatic zone or zone of saturation. This term often refers to plants known as"pump plants" In Greek, Phreat means "a well". I do not know if the term phreatophyte has ever been applied to Pecans trees by the scientific community. However, from my own observation, they can tolerate considerable drought. Dicots also produce lateral roots which grow in a smaller diameter than the primary roots. These are called secondary roots. Even smaller roots may grow from these secondary roots and these are called tertiary roots. From the tertiary roots and sometimes secondary roots, roots hairs may grow which are only the width of a single cell and sometimes only as long as one or a few cells.

 Root hairs are derived from the tertiary or secondary roots. Root hairs are very delicate and cannot be exposed to ordinary air without shriveling up. Root hairs are the primary structures for absorbing water. All the other sizes of roots have a cortex that is often quite impervious to water leaving the root hairs as the primary source of water uptake. Once they die they can no longer function and new root hairs must re-grow to pick up the water. This is why it is important to keep root hairs wet when transplanting. The best time to expose roots is in the morning when the humidity is high or when there is a light rain or heavy mist. Otherwise it is important to keep the root hairs misted until they are safely tucked away into the ground.

The roots of gymnosperms(conifers, such as pines) undergo similar developmental processes as the dicots. I have made an interesting observation regarding the roots of pines which may or may not occur in other gymnosperms. Where they are overlaid with concrete or similar hard material they frequently form a circular pad-like structure that presses up against the hard material. These structures are one half to three inches in diameter and their function is unclear to me at this time.

 Among the smallest of the root-like structures we see come from ferns. Ferns form attachments to the ground that are commonly referred to as roots but technically these structures do not quite fulfill the definition of a root as seen in angiosperms. These structures are commonly called rhizoids. Rhizoids are slender root-like filaments that perform similiar functions as roots in ferns, mosses and other gametophytes. However, with regard to ferns, the word root is used loosely because there is some question as to whether ferns form true roots as they are defined by higher plants. Some authors have chosen to use the term rhizoids (being root-like) instead of roots.

Over the years I have made many interesting observations about roots. For instance, on many plants , especially young plants, the early growth will supply a swollen area below ground called a lignotuber (i.e. Mirabilis jalapa, the four o'clock ). A lignotuber is a starchy swelling of the root crown. It offers protection to the stem from being burned or eaten by a predator. The lignotuber will sprout again and again ensuring plant survival. Other examples of lignotuber include several species of Eucalyptus such as Eucalyptus citriodora also known as lemon scented gum. Many, many plants produce lignotubers.

Starch performs an important function in plants.   Sugar, being soluble, is moved down into an area to be stored and converted to starch. There it remains throughout the winter. For example, in a potato, the mature tuber is starch that has been converted from sugar by the removal of one molecule of water from one molecule of sugar. This starch allows the tuber to store valuable energy for next years growth, whereas if  energy was stored as sugar the least injury to the plant would allow the sugar to be lost due to it's high solubility. In short the storage of starch allows a plant to retain energy in the form of insoluble starch. 

j

Enlarged storage area on the rots of Alstoemeria sp.

There are also enlargements that form down in the ground on the roots that act as storage for water and nutrients with no ability to form sprouts. It is important to note that these enlargements are strictly part of the roots and not lignotubers as previously discussed. Two examples of this include Asparagus sprengeri and Alstroemeria both in the Lily order. In some plants or trees, large buttresses or large burls which are portions of the tree that has grown in a deformed manner, serve a function not unlike a lignotuber. The buttress will sprout buds from the base of the tree if the tree is killed. It is common for people to say they are going to prune a tree to force new buds to grow. However, the concept of forcing a new bud to grow erroneous. The top growth is constantly sending down signals to suppress the buds below the ground from growing. If the dominant growing part of a the tree dies or is destroyed by fire, for example, then the buds below ground are allowed to sprout since they are no longer being suppressed by the growing plant.

Strangler Fig showing anastomosis

Another root form we see are aerial roots. They are found mostly in trees in tropical regions. They arise spontaneously  from the trunk or from the branches near the crown. They grow downward until they reach the soil and continue growing into the soil. It is reasonable to think that these new roots could be replacing, in time, older and often diseased roots. However, this is only a conjecture. A well known example of this root structure is the strangler fig tree which sends roots so numerous down the trunk of the tree that they will anastomose, or fuse together when they come into contact with one another as result of normal growth. The process of anastomosis forms a cylindrical tube around the tree. In time the supporting tree will die and decompose and the aerial roots are so well developed in this cylindrical fused structure that they will hold up the tree for some time. The decaying portion of the tree will provide nutrients for the remaining fig.

There is no end to noteworthy information that can be written about the roots of plants. I have mentioned some of the many interesting facts about roots but there are many more to be dealt with. I am continuously interested in and compiling new information on the morphology and behavior of roots and I am always in touch with other careful observers.  From time to time, I will share new observations on this blog.

Grasshoppers and Their Allies

There are three prominent insect families that are suggestive of grasshoppers that cause confusion for the unskilled observer. True grasshoppers(Acrididae), katydids(Tettigoniidae)and crickets (Gryllidae)are seperate families in the order Orthoptera and are often confused and misidentified. This blog is intended to eliminate confusion between these three families of Orthoptera. All three families share some similar characteristics such as over-sized and conspicuously enlarged hind legs used for jumping, that are often folded fan-wise beneath the front wings when at rest. The bodies of these insects are elongated. Stridulation, the rubbing of one body part against another to produce sound, is a common characteristic among these insects.



The family Acrididae are known as the true grasshoppers (image above image) and are separated from katydids and crickets by certain features. Grasshoppers have short antennae and tympanic (auditory) organs that are located on the sides of the first abdominal segment. These organs are concealed by the first pair of wings in adults. True grasshoppers are diurnal and stridulation occurs by rubbing the hind leg against the fore-wing. In the Acrididae, the ovipositor is short. True grasshoppers are herbivorous.






Both katydids(top image-just above) and crickets(bottom image) share some of the same characteristics not seen in true grasshoppers. Both are nocturnal and accomplish stridulation by rubbing their fore-wings together. Katydids and crickets can be predatory, omnivorous or herbivorous. Their tympanic organs are located on their forelegs and they have long antennae, often longer than their bodies, and long extended ovipositors. An interesting feature found in both groups of insects is their method of copulation. Almost all insects, copulate with the male mounting the females and aggressively holding on to the female. Crickets and katydids, are the exception and reverse the position during copulation. They have no way of aggressively mating with females instead they attract them with their stridulation and wait for the female to come to them and initiate copulation. Copulation is accomplished with the the female mounting the male.

What's so important about a name?

Sometimes in the field of taxonomy there are some misleading names that cause confusion and frustration. In the early days everyone was going crazy to have an opportunity to name species. Names were being slapped on species right and left without thinking it through. Sometimes, there were errors in transcription that led to unintened names. As a result some species are stuck with misleading names that in some instances can lead to erroneous assumptions. I'd like to mention some of these now.


Washingtonia robusta (left, right) and Washingtonia filifera (center)

Two of the most common species of palm trees planted in southern California are Washingtonia robusta and Washingtonia filifera. They are closely related and it is not uncommon to find hybrids between the two species yet the two plants are distinctly different in one feature-the trunk diameter. W. filifera has a stouter trunk and grows from 60-80 ft. tall. W. robusta has a narrower trunk, and tends to grow from 80 to 100 feet tall. The term robusta refers to something being stout in nature while the term filifera means thread bearing. Both species have threads at the margins of their leaf segments so the name filifera was not entirely distinctive in separating the two species. However, the name robusta should have been given to the species with the stouter trunk.

Ehrharta erecta is a non-native plant that has caused southern California great concern because it is choking out the native grasses along the coast. The species name erecta gives the impression that this grass stands up straight. However, only when it is crowded does it become somewhat erect but in general it is a prostrate plant. Therefore the word prostrata would have been far more appropriate name for this species. The fact that it is prostrate is of major concern to it's own propagation. the nearly horizontal new growing culms are just barely above horizontal if a plant is in a non-crowded environment. These prostrate inflorescence's weigh down to the ground with mature seeds and are a major feature of E. erecta's ability to reseed itself so successfully. I know two other species of Ehrharta that are uncommonly found in California, E. longiflora and E. calycina. In contrast to E. erecta, these two species grow completely erect. It is puzzling to me why the author chose Erecta for a plant that is prostrate, when other species are more clearly erect.

The scientific name of Jojoba, a native shrub of the southwestern United States is Simmondsia chinensis. The species name chinensis may impart that this plant has origins in China. However, it is only known to occur as a native plant in the southwestern United States. Shortly after this plant was named,there was an article written in a botanical journal suggesting that the name be changed before it was ingrained in the botanical society but this recommendation was refused.

While there are no hard and fast rules about naming species, I find for myself it is important that the names accurately reflect species characteristics or at the very least do not suggest something entirely uncharacteristic. If you know of other plant species that in your opinion are misnamed or do not accurately characterize a particular species please share these with me. This is something of interest to me and someday I'd like to gather a list of these species to share.

A long sought for name...The Lincoln Sparrow

For my fellow birders...

My early youth was devoted to the study of ornithology. From a very early age I started observing a particular bird with a most unusual flight habit. I noticed that when I walked towards a bush with this bird it would flesh instantly and fly just past the next bush a short distance,flip around in an in a very quick motion and dive back into the bush. I have never seen this peculiar movement in any other bird. For many years, I tried to ambush this bird to get a better look at it but was unsuccessful due to it's elusive nature and my poor long distance vision.

One day when Andy Sanders, the Curator of the UCR Herbarium and a long time friend, came to visit me he had opportunity to see this bird and was able to identify it immediately as a Lincoln Sparrow, a solitary bird in the same genus as the song sparrow. This was a great pleasure to me since I finally had a name for the bird that had eluded my identification since I was a child.

Honey and it's Attributes

Most of my younger years were consumed with observing and analyzing the behavior and features of insects. What I am reporting in this blog is based on those observations and my own experiences and will focus on bees and honey production and some of the lesser known facts and phenomenons associated with bees, pollination, nectar and honey production. Honey is the product of a very important process, pollination which is necessary for important crops both in the commercial and natural world.

Certain varieties of Almonds, avocados and citrus fruits, would not be productive without pollination. Almonds are especially dependent on honey bee's pollination. The reason being is that they require pollination for almond production and their supply of nectar is far less than most other stone fruits. Bees are not drawn to almond trees from very far away since they are not a very attractive source of nectar. To augment this almond growers will hire or rent out bee colonies from all over the country to pollinate the almond trees. Pollination is accomplished by proper planting and spacing of trees. Two rows of trees are planted side by side with the targeted variety that bring best market value. On either side of these two rows is one row of what they call a pollinator crop. This crop also makes fruit and is edible but do not make the same quality nut that is found in the choice varieties. Since both crops produce edible friut this type of pollination is said to be reciprocal.

There are many things about honey and pollination that few people are aware of. For instance, Rosemary produces no pollen and Navel oranges produces fair amounts of nectar, useful for commercial bee production, but no pollen. Apiarists, also known as bee keepers, often place hives in areas dominated by navel oranges but will, after a few weeks, move their bees to an area where they can get pollen such as an area dominated with wildflowers. Otherwise, the developing larvae in the hive would starve to death without the pollen.

Some plants have extrafloral nectaries which are modified hairs at the base of a leaf or on the stems of plants that produce a nectar-like substance. This substance is primarily consumed by ants and bee visitation is infrequent. Some plants that are known to make extrafloral nectaries are many members of the Orchid family and the Spurge family such as castor bean. Another example of a plant with extrafloral nectaries are found on the flowering stalk of sansevieria. Ants are attracted to this extrafloral nectar and in turn protect the plant from herbivores by deterring them.

One unusual situation occurs with the common tree Eucalyptus globulus , known as blue gum. They flower in late December and early January and produce copious amounts of nectar, especially high in moisture. This is a unique situation since the nectar needs to be dried down in order to become honey. This watery substance cannot be stored in the cells of the bee hive. This is because the substance does not have enough sugar content to prevent molding and would choke up the hive with mold. This anomalous condition was reported several times in the years of cold weather when I was younger. In warm weather bees are able to evaporate some of the water off during the flight to the hive in order to produce honey. However, in colder weather, water removal is difficult and honey production from Blue Gum is. Fortunately, the weather here is warmer now and the bees are able to obtain and use the nectar from Blue Gum without the risk of mold.

The most abundant honey producer that I am aware of locally is Manihot. Manihot is in the same genus as the commercial food plant which provides tapioca and the plant which provides cassava,an important starchy vegetable in tropics. Manihot looks like a bee hive in midday with loads of bees hanging on the flowers trying to get in. This is not something that everyone would see since it does not grow around here but it is something I have seen in my own garden.

In the hive the the workers bees feed the larvae royal jelly for a period of three days followed by diluted honey or a mixture of pollen and nectar. The larvae that are destined to become queens are fed royal jelly for a longer period of time and their cells are literally flooded with royal jelly. The royal jelly contains a protein called royalactin that cause the larvae to develop into queen bees. The metabolism of protein by bee larvae is greater than at any other stage of the bee life cycle when they rely more heavily on the sugar found in nectar and honey to function.

There are some plants that produce nectar that is ignored by the bees. These are usually plants that are not native to this area. There are several examples of plants non-usable to insects. tyle:italic;">Agave maculata and Grevillea robusta have flowers that produce nectar that is non palatable to humans. Melianthus major is another plant that is non-usable to insects but produces nectar that is quite palatable to humans.

Over the last years much attention has been paid to the collapse of honey bee colonies. Honey bees face many threats and there are many arthropods that attempt to the invade bee hives Honey is a very desirous item to ants and many other insects. One of these invaders is the wax moth,Galleria mellonia L. The wax moth invades the hives and somehow avoids being stung by bees. Perhaps this is because they are immersed in the odor of the hive. The larvae of the wax moths tunnel through hives they make trails of web like strands throughout the hive. They also attach themselves to frames and other parts of the hive to spin cocoons just before they pupate causing further damage to the hive. If the population of wax moths builds up in number they can damage the hive and can become detrimental to the entire colony.

Another arthropod that is becoming a threat to honey bees is the Phorid fly. This tiny fly attacks the bees and lays eggs onside their head. For about two weeks the bees act normally until the growing larvae upsets their nervous system as it feeds on brain matter and tissue causing the the bee to die. The larvae will then chew its way out of the head of the bees. There is much research currently being done on Phorid flies and the possibility that they may be a significant cause of colony collapse.

Other lesser know threats to honey bee colonies in certain situations are skunks and bears. Skunks will eat the incoming bees as they approach the hive. They eat them at the point when they are full of nectar, sometimes destroying the whole colony. Bears will rip the entire colony open to expose the comb to go after the brood and lap up the honey. Their thick fur prevents them from being stung and driven off. In areas where bears abound bee keepers have a lot of difficulty maintaining apiaries.

This is a little more than a brief sketch of the interesting facts and complexities of nectar and honey production. Much of this is based on my lifetime observation of plants and insects. Please feel free to share with me any interesting things you may have observed along these lines.

Little but Tough!

Picture courtesy of Wikepedia

Listen my children and you shall hear about the toughest animal in the world, Tardigrades. The word tardigrade comes from the latin word tardigradus meaning slow moving. Tardigrades, otherwise known as water bears, are microscopic animals that live in the water and in the soil. Tardigrades can be found all over the world from the highest reaches of the Himalayan mountains to the deepest ocean depths. There is little doubt that Tardigrades can be put into a category of being one of the earliest animals on planet earth.

Tardigrades, range in size from 0.05mm to 1.5 mm, which is about half the size of an Argentine ant. Despite their small size, Tardigrades can survive the harshest of environments. Tardigrades can survive up to 1000 times the radiation that other animals have been known to survive. They can tolerate extreme temperatures from close to absolute zero at -459 degrees Fahrenheit to as hot as 304 degrees Fahrenheit. Under total dessication they have been reported to survive for up to ten years but may survive much longer. Tardigrades can enter a state of crypotbiosis which is a state of suspended metabolism. Cryptobiosis allows tardigrades to essentially live forever until the environmental conditions can once again support the animal.

Tardigrades have been the subject of intense study as scientists try and understand how they have been able to inhabit the entire planet in some very extreme conditions. Tardigrades have even been taken to space and survived the dry conditions of deep vacuum and the harmful solar and galactic radiation. Research into what makes these animal tick is ongoing.

I was lucky enough to see tardigrades under a microscope while I was working in the department of nematology at UCR. We were working on a project to report on the nematodes that were found in the soil with reference to pathogenic forms. The tardigrades were captured incidentally while using a specific method of extraction to isolate nematodes out of the soil. I had only read about tardigrades up to that point. I was delighted to see them with my own eyes. It was a pleasure to find the tardigrades in the same filtration process as the nematodes. I look forward to finding out more about tardigrades as new information comes to light.