Inflorescences, buds and flowers
Floral structures traditionally hold the defining aspects of species. There are numerous characters associated with them. Basically there are two contrasting forms of floral architecture, the individual flower buds or flowers, and then their arrangement on the branchlets. In most species of eucalypts, the buds occur in clusters on single stalks in the axils of the leaves. The flowers are mostly small and whitish and are not conspicuous in the crown.
A very few species have the inflorescences in complex clusters in the leaf axils, e.g. E. michaeliana or on expanded axillary shoots as in some ghost gums, e.g. C. bella, C. tessellaris, and the spotted gums e.g. C. henryi, C. maculata, or in more contracted though still branched axillary shoots as in most ghost gums e.g. C. flavescens, C. polysciada. Four species from eastern Australia, E. fastigata, E. pachycalyx, E. regnans and E. squamosa, form their buds consistently in twin clusters in the leaf axils. In contrast, several large groups, the bloodwoods, some of the boxes and some of the ironbarks, form the individual bud clusters in large groups at the ends of the branchlets, with few or no leaves. In season these result in conspicuous sprays of flowers on the outside of the crown. A prominent example is the yellow bloodwood (C. eximia) of the sandstone regions of central eastern New South Wales, where the creamy white flower clusters stand out in the forest. In the south-west of Western Australia the widespread marri (C. calophylla) exhibits the same prolific flowering affect, although the southern Red-flowering gum (C. ficifolia) and the commonly cultivated northern Swamp bloodwood, C. ptychocarpa, are the most spectacular of the flowering eucalypts. One species, E. cladocalyx, has ramiflorous inflorescences, with the buds formed on the leafless part of the branchlets well inside the crown. Some ghost gums from northern Australia which are deciduous in the dry season, e.g. C. confertiflora, also appear to flower on leafless branches but these are cases where the floral buds have formed in the axils where last-season’s leaves used to be and the inflorescences are axillary, not truly ramiflorous. Very useful diagnostic information can be derived from these inflorescence patterns, although the structures can be modified by various external factors including predation.
A common modification of the basic axillary inflorescence of the eucalypts can be seen in many 'box', 'ironbark' and 'bloodwood' species. In these, bud clusters are formed in the usual way in the axils of developing leaves towards the ends of the annual growth of a branchlet. The arrangement of these leaves and floral primordia is initially decussate, and subsequent uneven elongation of the axis gives the appearance of alternation. Each branchlet terminates with a vegetative bud. In many 'box', 'ironbark' and 'bloodwood' species, this terminal vegetative bud aborts and the now apparently alternate leaf primordia cease their development. The floral primordia however, continue to develop, resulting in a 'leafless' compound inflorescence, terminating the branchlet. Good examples of this are E. paniculata, the common grey ironbark of south-eastern Australia, and C. calophylla, or Marri, common in south-western Australia.
The individual bud clusters in most eucalypts can be seen on close inspection to be in symmetrical patterns. A few species have a single bud in the inflorescence, e.g. E. globulus and E. macrocarpa, but the basic numbers in Angophora, Corymbia and Eucalyptus are 3 or 7. In a 3-budded inflorescence there is a central erect bud and two subtending side buds, all in a plane at right angles to the stem, forming a 'cross'. A 7-budded inflorescence has a central erect bud, two subtending side buds plus two buds each subtending the side buds. Bud numbers higher than 7 form by the addition of further pairs of subtending buds, and the number of buds in an intact inflorescence is always odd (never an even number), although very high bud numbers may occur in an obscured pattern. Also, in inflorescences with high numbers, one of a pair of subtending buds may be suppressed, probably by compression in the very young inflorescence which is tightly held within bracts which are soon deciduous. When assessing bud numbers, it is important to take into account the fact that during inflorescence development, which often takes more than a year, individual buds may be lost. This is particularly the case by the fruiting stage when the structures under examination have been exposed for a long time and subject to various traumas including predation and simple death of individual buds.
Angophora species and some of the northern bloodwoods (Corymbia setosa and related species) have simple hairs and bristle glands (erect multicellular hairs or setae) somewhere on the inflorescence, peduncle, pedicel, and often on the bud. The buds of Eucalyptus species are glabrous for their whole life cycle.
Angophora species are readily distinguished from other eucalypts in the flowers, by the presence of petals that have a green keel and white margin, and by persistent hard, woody, green sepals.
All Corymbia species and most Eucalyptus species do not have separate sepals. The exceptions are the species in Eucalyptus subgenus Eudesmia plus a handful of other species. Subgenus Eudesmia is widespread and consists of 21 species. In south-western Western Australia the most famous is the glaucous, juvenile-leaved Tallerack (E. pleurocarpa). In this and related species, the calyx is formed of distinct separate sepals which are usually evident as four small teeth at the top of the hypanthium and usually persist to the fruiting stage. A northern example is the Darwin Stringybark, E. tetrodonta, which in bud has prominent sepals that persist in fruit. Another group of eudesmids have their sepals more or less fused to the corolla right at the apex of the bud and usually are difficult to see. Examples of this are E. baileyana from Queensland and northern New South Wales, E. ebbanoensis from south-western Western Australia, and the orange-flowered tropical trees E. miniata and E. phoenicea.
Other Eucalyptus species having separate sepals are E. microcorys, which has, in early bud development, very small calyx lobes formed at the top of the hypanthium but which fall early and are seldom seen, and the south-western species E. steedmanii and E. mimica where conspicuous sepals are present in bud but are lost on flowering; the Queensland endemic species E. curtisii, E. cloeziana and E. tenuipes, with four small teeth present on the mid line of the bud which persist in E. curtisii but fall early in the other two. In all other species in Eucalyptus and in Corymbia the sepals are united to form the outer operculum or bud-cap.
The individual flower buds have two opercula (bud caps covering the stamens and style) derived from the united sepals (outer operculum) and united petals (inner operculum). In some species of red bloodwood the fusion of the petals to form the inner operculum may not be complete, but careful dissection is needed to see this. A longitudinal section through an almost mature bud can reveal whether or not the inner operculum is divided at all. Similarly, removing the outer operculum but leaving the inner operculum intact can also show whether the inner operculum is partially divided or not. Some examples in the bloodwoods are C. ficifolia, C. zygophylla and C. deserticola. Eucalyptus guilfoylei from the wet forests of southern Western Australia may also possess this feature of the inner operculum.
The flower buds of Angophora (illustrated above) are all very similar within the group of twelve species and subspecies and, apart from size, contain very few discernible characters that distinguish the species. The individual flower buds of the traditional eucalypts, however, contain a great deal of vital information, from the external superficial nature of the wall of the bud to the characters of much higher reliability contained within. One character of absolute reliability (no exceptions have ever been found) is the number of opercula, although this requires experience to assess.
Except for Angophora, the eucalypt flower lacks showy petals. The petals are in fact united very early in bud development to form a cap or a cone-shaped structure that covers the stamens and ovary during their development. This is the inner operculum, which sheds just before flowering when the stamens expand and are almost ready to shed their pollen. (There is a delay in pollen ripening and dispersal to lessen the chance of self-fertilisation and consequent inbreeding). The outer whorl of the floral parts is the sepals which, likewise, unite to form an operculum in most eucalypt species. In the majority of species, this, the outer operculum sheds early in bud development. In doing so, the tissue around the approximate middle of the bud, i.e. where the outer operculum attaches to the base of the bud, dies resulting in detachment. This leaves a scar around the middle of the bud which can sometimes be seen with the naked eye but is best seen with a lens. About 130 species, comprising the Eucalyptus subgenus Eucalyptus, have lost the outer operculum altogether in the evolution of the group. Therefore, throughout the development of the bud in these species there is no scar, and the side of the bud is smooth. Some species have two opercula that are fused giving the superficial impression that only a single operculum is present, e.g. E. ochrophloia. The boxes and ironbarks show parallel development in operculum characters. There are two groups, one in which the outer operculum sheds early leaving a scar, e.g. the box species, E. behriana, and the ironbark species, E. paniculata, and another in which the outer operculum is held to bud maturity, e.g. the box species, E. microcarpa and the ironbark, E. sideroxylon. The double opercula and their retention to bud maturity is a diagnostic feature of all the red bloodwoods (Corymbia informal section Rufaria). The ghost gums (Corymbia informal section Blakearia e.g. C. bella) and spotted gums (Corymbia informal section Politaria e.g. C. citriodora) shed the outer operculum during bud development leaving an operculum scar.
Stamens have various forms of orientation in the unopened bud. Some species have their stamens wholly erect. Others have them uniformly inflexed, while others have irregular orientation. Again, the extremes of positioning, i.e. complete inflexion or complete erection, are easy to assess. However there will be 'in-between' species in which the character is difficult to categorise. The attachment of the anther on the summit of the staminal filament is useful diagnostically. Some anthers are basifixed, with the tip of the filament attached rigidly at the base of the anther. This character is seen in the boxes and ironbarks and at its most extreme in E. leptophylla, E. foecunda and related species. In the majority of eucalypts the anthers are dorsifixed, by attachment loosely to the back of the anther, such that it can swivel, i.e. versatile. Some eucalypts have flowers with staminodes, where the outer stamens lack anthers or have reduced, non-functional anthers, e.g. E. calycogona. The openings of the anther for pollen shed (dehiscence) is also an important diagnostic character. Most eucalypts have their anthers either opening by well separated longitudinal slits for the more or less cuboid anther, or, as in Eucalyptus subgenus Eucalyptus (e.g. E. regnans) with their more or less kidney-shaped anthers, have the openings oblique and touching near the apex, finally forming confluent slits. The cuboid, freely dorsifixed anther occurs in many western species but the kidney-shaped anther with confluent slits is rare in western monocalypts but is seen in Jarrah (E. marginata) and a few related species. The butterfly-shaped anther inE. guilfoylei is unique in the genus. In a considerable number of species, particularly mallees, e.g. E. oleosa, the anthers are subversatile and open by small roundish pores, either at the sides or the top of the anther.
Within the base of the bud is the ovary and this contains characters of high diagnostic reliability. The most useful is the number of vertical rows of ovules. These can only be seen by dissection and is best done under a microscope but can be done in the field and seen with a 10× lens. Most eucalypts have ovule rows with 4 or 6 vertical rows. Another group has ovule rows consistently in 2s (Eucalyptus subgenus Eucalyptus), while others have rows of 3 or 5, or irregular patterns (bloodwoods and ghost gums).
The top of the ovary is surmounted by the style which terminates in the stigma. The style is usually erect in all but a few species but can be spiral in some e.g. E. albida, making it a useful diagnostic character. In the great majority of species the style arises from the narrowed summit of the ovary. In some bloodwoods, in Eucalyptus series Melliodorae (e.g. E. leucoxylon) and some species of Eucalyptus series Loxophlebae (e.g. E. loxophleba) the style narrows at the base and is inserted into the roof of the ovary. The style is subsequently articulate, not rigid.
The pollen is transported to the stigma from another flower by insects, small birds or small mammals. On germination of the pollen grains, the contents including the vital nuclei migrate by means of a pollen tube down the stigma shaft to the ovary itself where several ovules at the base of the placentae are fertilised. The fertilised ovules mature into the seeds. The ovular structures on the upper part of the placentae are infertile or unfertilised and 'mature' into sterile particles smaller than the seeds known as the chaff.
Henry David Thoreau once said, “If you would convince a man that he does wrong, do right. However, do not care to convince him. Men will believe what they see. Let them see.” In terms of academic writing, this phrase means being able to draw visual images with the help of words. What is an illustration essay? An illustration essay is what best describes a paper written to create a picture in the reader’s mind and deliver the target message more effectively. In this article, we will discuss the meaning, topic, and several examples of the illustration essay.
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Illustration Essay Definition & Usage
A student may ask, “What is an illustration essay”? It is a logical question. This genre of writing is rare compared to argumentative, persuasive, compare & contrast, or narrative papers. Illustration essay interprets specific situation/person/object by providing certain examples and different details to let the reader understand the selected topic broader. To understand different types of academic essays better, you may like the website full of free essay examples.
Here is the list of illustrative essay examples. Choose the topic without conducting research!
- Use specific sports terms to illustrate how to swim a stroke in Olympic swimming, dive, or demonstrate other abilities in the water.
- Explain how dancing/acting on the stage is different from the high school cheerleading; what is a higher art?
- Discuss why a sports team of your preference (basketball, football) is underrated; why the soccer team you dislike is overrated.
- Illustrate the stages a college applicant should take in writing a winning college entrance essay to join the target educational institution.
- Share how you managed to survive your first year in college with your readers by writing several effective tips from your experience.
- Explain how you used to flirt with the opposite gender correctly to avoid being a part of the “friendship zone.”
Work & Career
- Show the way professional scientists conduct research by describing every required step in details.
- Explain what an HR manager does; write down several examples from your personal interaction with the representatives of this profession.
- Illustrate what a chief from the prestigious restaurant downtown does to cook the dish of the day (e.g., a deer).
- List & explain the features of a good business writing (e.g., make a list of the winning professional terms/keywords, which helped you to pass a job interview).
- Write about the city, which used to survive some natural disaster (an earthquake, tsunami, tornado, hurricane, etc).
- The topic on how society can support children who became the victims of school bullying/hate crimes/home violence.
How to Write an Illustration Essay
Writing an essay is made of five basic steps. Before writing your paper, decide on the most effective title.
Step 1: Identify the object of your writing (a.k.a. the main illustrative essay topic) and write a powerful thesis statement, which will impress both the teacher and entire reading audience. Help your reader to understand your topic ahead. Pick minimum three keywords/points to explain why you believe/deny the specific idea - this sentence is your thesis statement.
Example: “Gender stereotypes exist in the professional world. Many business companies prefer having men as their CEOs.”
Step 2: You are almost done with your introduction paragraph. Keep on writing what you are going to share with the reader, and provide reasons for choosing a particular topic. Start the first paragraph with the hooking sentence. Several types of the hooks exist to consider: direct quote, poetry line, metaphor, simile, joke, fact, etc. This technique will grab the reader’s attention from the first line of the essay. [Learn here how to write an analytical essay]
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Step 3: Your illustration essay should be supported by the good outline (an essay outline serves as the action plan for your writing from cover to cover). Keep on writing a paragraph supporting each reason why you chose a specific essay topic until you get three good reasons.
Example: “Last time I attended a job interview, I have lost my place to Mr. Green, and the only ‘good’ reason the local HR told me is he believes women do not possess powerful marketing ideas to help their company”.
Step 4: It is the easiest step in the essay writing. The writer must list three points explaining why he chose the specific illustration topic/example at the beginning of each sentence, and then support it with the meaningful evidence retrieved from the research.
Step 5: After writing a conclusion, a professional writer would like to double-check the entire essay for the following mistakes:
- Grammar & spelling
- Plagiarism & other small issues
Even if you know how to write an illustration essay perfectly, do not ignore the stage of proofreading & editing, or hire professional online editors to check your final paper.
Types of Examples You May Use to Support an Illustration Essay Thesis
To answer, “what is an illustration essay,” the student must realize the importance of examples taken from personal experience. You should support an illustration essay with the vivid examples from your personal experience. Use several good methods to get inspired: personal observation, interviews, experience, & media.
A personal observation requires observing different locations related to your chosen topic. Do not forget to take notes explaining your impressions through five human senses.
An interview means having a face-to-face conversation with people who are experts in the fields connected with your topic. These people can share exciting examples so that your writing will stand out from the rest of the papers. Conduct a research to prepare a list of related questions before contacting the people of your interest.
Recall your personal experience to include in your writing. Personal memories are a good source of ideas you can share with the readers to support the main argument. Research & look at some images to jog your memory. Write every topic detail you remember from your personal life experience; do not forget to include sensory expressions & comments from other people. Let the adjectives and adverbs help you with your writing.
Media is one of the most useful sources of ideas & examples in the modern world. Spend some time on social networks (Facebook, YouTube, Instagram) where people of all types share their experience by writing meaningful posts or publishing interesting videos. Pick the best topic examples for your illustration essay from the following sources:
We hope that after reading the article from the market specialists, you understand the answer to the questions like, “What does illustrate mean in an essay?” If you want more illustration essay examples, help with the research, or good points to catch the reader’s eye, we have a solution. Just make an order! Go to the official academic writing service’s website to get the top-notch papers at affordable prices!
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