Plant Seed: The Reproductive Organ of the Angiosperms

The plant seed is an organ found in plant shoot, attached to the stem, and originating from a flower.

It is a structure that is formed by the maturation of the ovule within the ovary of the angiosperms.

It is often described as a “mature ovule”. 

In angiospermous plants, the natural process of seed development occurs through double fertilization.

This proceeds after pollination, the transfer of pollen grains from an anther to the stigma of a flower.

In double fertilization, one of the two sperm nuclei (1N) in the germinating pollen (pollen tube) unites with the egg nucleus (1N) in the female gametophyte or embryo sac within the ovule to form the diploid (2N) embryo of the seed.

The other sperm nucleus (1N) in the pollen tube unites with the polar nuclei (2N) in the embryo sac to form the triploid (3N) endosperm.

Meanwhile, the surrounding integuments of the ovule form the seed coat (2N).

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List of Fruits in the Tropics (A-L)

Table F-1a shows a list of fruits that should serve as a reference for fruit crops that are common in the distribution or grown as commercial crops in the tropics.

Emphasis is given to crops with fleshy dessert fruits including cashew which produces a pseudofruit.

Most of these crops are listed in E.D. Merrill’s A Flora of Manila published in 1912 but many of the scientific names have since been modified.

The crops are arranged alphabetically by their common names, generally English names.

This web page is one of two pages and consists of a list of fruits in the tropics with common names that start from A (acerola) to L (lychee).

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List of Vegetables: IV. Examples of Fruit Vegetables

Fruit vegetables are collectively one of the many high-value crops that entrepreneurial farmers grow.

Consequently, many companies engage in the breeding of superior varieties of vegetable crops such as tomato, eggplant, peppers (Capsicum), bitter gourd, bottle gourd, string beans, and many more.

bell pepper
Freshly harvested fruits of bell pepper

These vegetables are a common scene in wet market stalls. Likewise, these are commonly grown in residential backyards.

Some even utilize the boundary fences as trellises for climbing plants such as string beans or pole sitao, lima beans, and winged beans.

Standing trees are likewise used for climbers with relatively large fruits like bottle gourd, luffa, and chayote.

But did you know that one fruit vegetable became the subject of a legal controversy?

In the case of tomatoes, the issue of whether it was a fruit or a vegetable had to be decided by the US Supreme Court. Click here to read.

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The Functions of Fruits Are Inherent in Plants & Also Used in Plant Propagation

The functions of fruits in the angiosperms are mainly in relation to reproduction by which plants perpetuate their species.

The fruit is in fact described as a reproductive organ of plants just like the flower and seed.

However, the functions that fruits perform in reproduction are indirect. 

jackfruit
A well-developed fruit of jackfruit, indicating that the seeds inside are fully developed as well as the edible parts

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Simple Fruits and Unit Fruits, Description and Crop Examples

Simple fruits are those fruits in the angiosperms that develop from a single ovary of one flower.

This ovary may be either simple or compound. Unit fruits or true fruits are those that represent the individual components of an aggregate or multiple fruits.

Various types of fruits are here listed and described.

However, there are fruits having characteristics that do not perfectly fit into the specific description of any fruit type for which such terms as drupe-like, berry-like, and nut-like are used.

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What Is a Fruit in Relation to Plant Structure in the Angiosperms

What is a fruit? This question is always asked in association with another question “What is a vegetable?”

These questions are repeatedly asked and without doubt, will be asked over and over again.

The reason is that the word fruit has many meanings based on various criteria. It can refer to a part of a plant, a type of tree or crop, or a particular food item.

As to vegetables, there is a special classification called fruit vegetables which refers to crops in which botanical fruits are harvested primarily for use in culinary preparations, such as tomato and squash.

Indeed, based on common usage, fruits refer to the plant structure having sweet, edible portions and generally consumed raw as contrasted to vegetables which refer to edible plant parts which are generally consumed cooked but some in raw form as a salad.

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What Is a Flower, Common Uses and Misuse of the Word

“Alright class, draw a complete flower showing its parts.”

That was the instruction of a teacher who gave a surprise quiz to assess the basic learning of his students about plant structures.

To his surprise when he checked the papers, some drew a potted mature plant complete with the parts of the shoot from trunk to blossoms. It elicited a grin, nonetheless.

On second thought, it should not be a surprise.

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The Advent of the Angiosperms: Why Are They Important?

The angiosperms or true flowering plants are presently the most dominant plants on Earth, comprising more than 95% of all existing plants (embryophytes or land plants).

They also represent most of the agricultural and food crops (Kesseler and Stuppy 2009; Simpson 2010).

It is just proper therefore that this group of plants is accorded special concern.

These plants consist largely of monocotyledons and eudicots.

Combined, they comprise 246,000 described species, equivalent to 97% of all angiosperms as of 2010 (Simpson 2010).

Mathematical derivation indicates that there are more than 250,000 species of angiosperms.

These flowering plants exhibit wide diversity.

They occur in various sizes, forms, growth habits, life spans, and habitat preferences.

Their sizes range from less than 1 mm in diameter, as in the smallest flowering plant Wolffia, to more than 90 meters or 300 feet in height as in the eucalyptus trees of Australia.

Wolffia is a water surface dweller and produces the smallest flowers.

Although orchids may not appear so extraordinary, they produce seeds that can be less than 0.2 mm wide (waynesword.palomar.edu 2012), the smallest seeds.

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Self-pollination and Cross-pollination, Other Types of Pollination and Agents of Pollination

Various types of pollination occur in seed plants.

As to plant-to-plant pollen transfer, two types exist self-pollination and cross-pollination.

Classification has also been made according to agents of pollination.

Having a sufficient understanding of these pollination mechanisms is important in crop agriculture.

Knowing the normal mode of pollination of any crop can accelerate crop improvement works because plant breeding methods are pollination type-dependent.

Proper cultural management practices, such as in relation to pests and diseases control and biodiversity, can be identified to favor populations of animal pollinators.

The process of pollination precedes fruit and seed formation in the angiosperms and seed formation in the gymnosperms.

Both fruits and seeds perform functions in plant reproduction. In particular, the seeds serve as the major, immediate, direct progenitors of new plants.

In addition, many agricultural crops are grown for the primary purpose of producing either fruits or seeds or both.

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