Legumes and the Fabaceae Family

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Questions and Answers

What type of leaves are most commonly found in the Caesalpiniaceae family?

Pinnate or bipinnate (correct)

Entire margin

Quadripinnate

Simple or bilobed

Which of the following species provides a powerful laxative?

Honey locust

Senna (correct)

Tamarind

Carob

What is a notable use of tamarind pods?

Flavoring in sauces (correct)

Construction material

Animal feed

Paper production

What morphological feature is observed in Petalostylis species?

Petal-like style that attracts insects Signup and view all the answers

What characteristic is observed in Labichea species within the Caesalpiniaceae family?

Only two stamens Signup and view all the answers

What was the main reason O'Neill expressed relief regarding the Vienna decision?

To retain the name Acacia for Australian species Signup and view all the answers

What is the floral arrangement of Acacia flowers typically characterized by?

Clusters of many small flowers in heads or spikes Signup and view all the answers

Which statement accurately describes the leaves of many Australian Acacia species?

They possess only phyllodes and no true leaves. Signup and view all the answers

What is the floral symmetry of Acacia flowers?

Actinomorphic Signup and view all the answers

Which of the following is true about the structure of Acacia flowers?

They consist of two whorls of inconspicuous petals and sepals. Signup and view all the answers

Which of the following is a key characteristic of plants in the Fabaceae family?

They are high in nitrogen due to bacteria association. Signup and view all the answers

What happens to the leaves during the development of species with phyllodes?

The first leaves are always compound true leaves that later develop into phyllodes. Signup and view all the answers

Which subfamily of Fabaceae includes the group commonly known as wattles?

Mimosoideae Signup and view all the answers

Which of the following accurately describes phyllodes in Acacias?

They function like true leaves and are flattened in a specific orientation. Signup and view all the answers

What role do Acacia species play in their ecosystems, especially in disturbed sites?

They improve soil nutrition and act as early colonizers. Signup and view all the answers

Why did the Australians celebrate the wattle as a national symbol?

It helped them gain the rights to the name Acacia. Signup and view all the answers

What is the significance of the golden wattle (Acacia pycnantha) to Australia?

It symbolizes Australia's national colours and is the national flower. Signup and view all the answers

Which statement about the distribution of the Acacia genus in Australia is correct?

About 50% of Acacia species are native to Western Australia. Signup and view all the answers

What event celebrates the cultural importance of wattle in Australia?

Wattle Day on September 1 Signup and view all the answers

In terms of habitat, which of the following is NOT a typical environment for members of the Fabaceae family?

Arctic tundras Signup and view all the answers

Which of the following statements about the subfamily Caesalpinioideae is true?

It is known for members commonly called cassias. Signup and view all the answers

What is a characteristic of Acacia leaves?

Bipinnate and compound Signup and view all the answers

Which use of Acacia wood is NOT mentioned?

Production of musical instruments Signup and view all the answers

What was a traditional use of Acacia roots by Aboriginal people?

Hosting edible grubs Signup and view all the answers

What is the primary agricultural benefit of Acacia species?

Providing shelter and fodder Signup and view all the answers

What is the national emblem of Australia?

Golden Wattle (Acacia pycnantha) Signup and view all the answers

Which family does the Acacia belong to?

Mimosaceae Signup and view all the answers

What characteristic feature is NOT typical of the Caesalpiniaceae flowers?

Sepals and petals fused Signup and view all the answers

How are the stamens characterized in the flowers of the Senna genus within Caesalpiniaceae?

Typically 7-10 and may include staminodes Signup and view all the answers

What is the primary type of fruit produced by the Fabaceae family?

Legume Signup and view all the answers

Which of the following subfamilies is NOT part of the Fabaceae family?

Brassicaceae Signup and view all the answers

Where is the greatest diversity of legume species typically found?

Tropical and subtropical areas Signup and view all the answers

What is a key ecological relationship that legumes have?

Their seeds are collected by ants. Signup and view all the answers

How many species belong to the Caesalpiniaceae family within the Fabaceae?

52 Signup and view all the answers

What advantage do ants provide to legume seeds?

They protect the seeds from predators. Signup and view all the answers

Which of the following statements about Western Australian legumes is true?

All are monophyletic in classification. Signup and view all the answers

What is the function of the elaiosomes associated with legume seeds?

To provide a food source for ants. Signup and view all the answers

Study Notes

General Background & Distribution

Family Fabaceae, also known as legumes, is the third largest flowering plant group, comprising 18,000 species in 650 genera.
The highest diversity occurs in tropical and subtropical regions, with absence in Antarctica and the Arctic.
Australia hosts 1885 species, with over 1400 found in Western Australia (WA).
Legumes are essential for food, fodder, and timber, second only to grasses globally.

Taxonomy

Fabaceae consists of three main subfamilies:
- Mimosoideae (Wattles)
- Caesalpinioideae (Cassias)
- Papilionoideae (Peas)
Monophyletic classification: all subfamilies are part of one family, Fabaceae.

General Characteristics

Fruit type: legume (pod) formed from a single superior carpel, dehiscent into two valves.
Ripe legumes dry and split to release seeds.
Seeds are high in protein and often collected by ants due to special food bodies (elaiosomes), enhancing their survival chances.

Nitrogen Fixation

Legumes have a symbiotic relationship with bacteria, namely Rhizobium and Bradyrhizobium, located in root nodules.
This nitrogen fixation process improves soil quality and contributes to protein-rich plant sources.

Morphological Traits

Habit: includes trees, shrubs, scrambling subshrubs, vines, or herbs, adapting to diverse habitats from deserts to rainforests.
Specific features include:
- Mimosaceae (Wattles): Common genus Acacia, with over 1000 species in Australia, often found in arid conditions.
- Caesalpiniaceae (Cassias): Approximately 150 genera and 2200 species, prevalent in tropical regions.

Floral Morphology of Acacias

Flowers arranged in heads or spikes, featuring prominent stamens exserted beyond petals.
Actinomorphic and bisexual, with two whorls of inconspicuous petals and sepals.

Vegetative Morphology of Acacias

Characterized by woody trees and shrubs, with bipinnate leaves.
Some Australian species have phyllodes (flattened petioles) replacing true leaves, adapting for survival.

Aboriginal and Current Uses of Acacias

Historical uses include food (seeds, pods), and materials for tools and nets.
Current applications involve timber (such as Blackwood), shelter belts, food (wattle seed), and wildlife habitat restoration.

Importance of Acacia as National Symbol

The Golden Wattle (Acacia pycnantha) is Australia’s national flower, symbolizing the country's identity.
Wattle Day, celebrated on September 1, marks the first day of spring and has cultural significance for Aboriginal communities.

Overview of Caesalpiniaceae

Noted for their zygomorphic flowers and diverse leaf forms, including pinnate and bipinnate leaves.
Economically significant for laxative-producing species (Senna) and culinary uses (tamarind and carob).

Key Examples of Genera

Mimosaceae: Dominated by Acacia species, adapted to various environments.
Caesalpiniaceae: Includes genera like Senna, Labichea, and Petalostylis, each having unique floral and vegetative traits.

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Description

Explore the fascinating world of legumes, a vital member of the Fabaceae family. This quiz covers their general characteristics, global distribution, and subfamilies including Mimosoideae, Caesalpinioideae, and Papilionoideae. Test your knowledge and learn more about these important flowering plants.