Fabids
Spring 2014

Fig. 8.1

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Comprise about 25% of all angiosperms
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Includes two main clades: fabids and malvids
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Main support for monophyly from molecular data
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No clear morphological synapomorphies, but tendencies to have perianths with unfused parts and a stamen merosity > calyx or corolla, although there are many exceptions
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Extreme variation in habit (trees, shrubs, herbs, vines, etc.) as well as extensive proliferation of floral syndromes, including wind, insect, bird, and bat pollination
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Transition from apocarpy to syncarpy as seen before; fusion and embellishment of floral parts

Fig. 8.30

Fabids:
Order Malpighiales
Order Fabales
Order Rosales
Order Cucurbitales
Order Fagales
Malvids:
Order Brassicales
Order Malvales
Order Sapindales

Core Eudicots: The Rosids - Fabids
Order Malpighiales
Euphorbiaceae* – Spurges
Salicaceae* – Willows and poplars
Violaceae – Violets
Order Fabales
Fabaceae* – Beans
Order Rosales
Rosaceae* – Roses
Moraceae – Figs, mulberries
Ulmaceae
– Elms
Order Cucurbitales
Curcurbitaceae* – Cucumbers, squashes
Begoniaceae – Begonias
Order Fagales
Betulaceae – Birches
Fagaceae* – Oaks, beeches, chestnuts
Juglandaceae – Walnuts, hickories
*Family required for recognition

Rosids-Fabids:
(The Spurge Family)
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Widespread, but most diverse in tropical regions
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Trees, shrubs, herbs, or vines, sometimes succulent; leaves usually alternate
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Diversity: ca. 6,300 species in 218-245 genera
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Flowers: Unisexual; sepals 2-6; petals 0-5; carpels usually 3, ovule 1 per locule; styles usually 3 and sometimes divided; inflorescences often highly modified; fruit a schizocarp, seeds usually arillate
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Significant features: Often with latex/laticifers
(toxic)
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Special uses: rubber (Hevea), cassava/manioc
(Manihot), poinsettia (Euphorbia), ornamentals
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Required family; required genus: Euphorbia

Unisexual flowers in Euphorbiaceae female male

• Ca. 2,400 species
• White latex (usually)
• One female and few to many male flowers aggregated into a cyathium
(one type of false flower or pseudanthium)
• Cyathium subtended by modified leaves (cyathophylls)

Euphorbiaceae: Euphorbia cyathium
From the Euphorbia
PBI website

Digital Flowers

• Castor oil plant (Ricinus communis) castor bean ~ poisonous seeds

• Rubber (Hevea brasiliensis)

• Tapioca, Cassava (Manihot)
Manihot esculenta cassava, tapioca

• Tung oil (Aleurites)
Aleurites fordii tung-oil tree

Rosids-Fabids:
(The Willow or Poplar Family)
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Widespread, from tropical to north temperate and boreal regions
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Trees or shrubs
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Diversity: 1,200 species in 54-55 genera
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Flowers: bisexual or unisexual; sepals 3-8; petals 3-
8; stamens 2∞; carpels 2-4, connate, in superior ovary; fruit variable
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Significant features: leaves simple, often with salicoid teeth; salicin in most; includes what was formerly called the “Flacourtiaceae”
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Special uses: lumber, shade trees, ornamentals
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Required family

Salicaceae: Salix
-bud scale single
-catkins usually erect or ascending
-flowers unisexual
-each flower with 1-4 basal nectar glands
-stamens 1-12
-mainly insect pollination

-bud scales several, overlapping
-catkins arching or drooping
-flowers unisexual
-each flower with a basal cup-like disk
-stamens 8-numerous
-wind-pollination

Rosids-Fabids:
(The Violet Family)
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Widespread, but predominantly herbs of temperate regions
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Herbs, shrubs, or trees
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Diversity: 700-800 species in 23-24 genera
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Flowers: Sepals 5; petals 5; 5 connivent stamens; carpels usually 3, connate, superior ovary; fruit usually a loculicidal capsule
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Significant features: Zygomorphy, nectar spurs; floral cleistogamy
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Special uses: Violets grown primarily as ornamentals
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Family not required

connivent stamens nectar spur

Violaceae: dual breeding systems
-spring flowers open-pollinated, summer flowers remaining closed (cleistogamous)

Rosids-Fabids:
(The Legume Family)
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Nearly cosmopolitan
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Herbs, vines, trees, shrubs with usually alternate, stipulate, pinnately to palmately compound leaves (sometimes unifoliolate or simple)
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Diversity: 19,500 species, 720-730 genera – THIRD LARGEST FAMILY of angiosperms
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Flowers: a short, cup-like hypanthium present; sepals & petals usually 5, free or connate; petals all alike or the uppermost 1 differentiated (banner), the lower 2 forming a keel or flaring apart; stamens 5 or 10-many, if connate then monadelphous or diadelphous; carpel 1, on a short stalk
(gynophore); fruit is a legume (Duh!) but sometimes modified
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Significant features: High nitrogen metabolism w/ unusual amino acids, often with root nodules with N-fixing bacteria; leaf and leaflet pulvinuses well developed; endosperm often lacking; wide range of floral diversity
Special uses: Many!! Beans, peas, peanuts, soybean, clover, ornamentals (Mimosa, Bauhinia); lumber, dyes, resins
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Required family; required taxa: Mimosoideae , “Caesalpinioideae”,
Faboideae

Fabaceae vegetative characters root nodules pulvinus compound leaves

Perigynous flower, short hypanthium
Diadelphous stamens:
9 + 1 gynophore
Marginal (parietal) placentation

Fabaceae fruit and seed characters non-endospermous seeds at maturity legumes, loments, etc.

Mimosoideae
Leaves usually twice pinnately compound
Fls actinomorphic, petals valvate, distinct or basally fused
Stamens 10-many, distinct or basally fused
“Caesalpinioideae”
Leaves usually once pinnately or twice pinnately compound
Fls + weakly zygomorphic, upper petal usually innermost; petals distinct
Stamens 5 or 10, distinct
Faboideae
Leaves pinnately compound to trifoliolate
Fls zygomorphic, upper petal (banner) outermost; well defined wings and keel
Stamens 10, monadelphous or diadelphous

Fabaceae – Subfamily Mimosoideae
Albizia julibrissin
Acacia sp.

Actinomorphic tubular flowers in heads
many stamens, not fused
Albizia julibrissin mimosa, silktree

Bullhorn acacias: “My enemy’s enemy is my friend.” stipular spines extrafloral nectaries
Tropical dry forest elaiosomes

zygomorphic flower pulvinus
Stamens not fused
-10 or fewer
Senna obtusifolia sicklepod

Fabaceae : “Caesalpinioideae”
Cercis canadensis - redbud

Honey locust (Gleditsia)

Lathyrus sweet-pea
Digital Flowers

Petals unequal:
• banner
• wings
• keel monadelphous stamens bacterial root nodule
Crotalaria spectabilis showy rattlebox

Fabaceae – Subfamily Faboideae

Glycine
(Soybean)

Beans, peas, lentils, chickpeas, etc.
extraordinary economic importance

Trifolium
(Clover)
Medicago (sweet clover)

Rosids-Fabids:
(The Rose Family)
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Cosmopolitan, primarily in the Northern Hemisphere
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Herbs, shrubs or trees (75% woody plants)
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Diversity: 2,500-3,000 species in 85-90 genera
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Flowers: Showy, actinomorphic, hypanthium present; sepals 5; petals 5; stamens usually numerous; carpels
1 to many, apocarpous or syncarpous; ovary superior or inferior; fruit can be a follicle, achene, pome, drupe, or associated with expanded receptacle
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Significant features: Wide range of fruit evolution within family; leaves alternate, stipules present
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Special uses: Fruits (apples, pears, berries), ornamental herbs, trees, and shrubs; lumber, perfumery
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Required family

Rosids-Fabids:
(The Fig Family)
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Widespread, from tropical to temperate regions
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Trees, shrubs, or vines (sometimes herbs)
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Diversity: 1,500 species in 53 genera
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Flowers: Unisexual, inconspicuous; tepals 0-4 or 5
(-8); carpels usually 2, connate, superior ovary; inflorescences cymose, highly modified, compact, receptacle expanded; fruit is a drupe, often in a multiple fruit structure (syconium).
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Significant features: laticifers/latex throughout the plant
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Special uses: figs (Ficus), mulberries (Morus), breadfruit (Artocarpus), ornamentals, e.g. osage orange (Maclura)
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Family not required

Moraceae Dorstenia
Ficus carica – Cultivated Fig
Artocarpus
(breadfruit)
Morus rubra - Mulberry
Maclura pomifera
Osage orange

-shrubs or trees
-about 800 species worldwide
-flowers minute, borne inside the syconium
-wasp-pollinated
-possible keystone species in tropical forests

Moraceae – The Fig and The Fig Wasp

Rosids-Fabids:
(The Cucumber or Squash Family)
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Widespread in the tropics and subtropics, a few in temperate regions
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Herbaceous or soft woody vines with scabrous stems and palmately veined/lobed leaves and usually with tendrils
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Diversity: 900 species in 118-122 genera
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Flowers: hypanthium present; sepals & petals 5, usually connate; stamens 3-5; carpels usually 3; ovary half-inferior or inferior; fruit usually a berry (with hardened rind a pepo); seeds flattened, the seed coat with several layers
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Significant features: wide range of floral diversity, “toothed” leaves lacking stipules; female flowers epiperigynous
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Special uses: cucumbers (Cucumis), pumpkins, gourds, and squashes (Cucurbita), watermelons (Citrullus) etc. are eaten for fruits and seeds; Luffa, some ornamentals
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Required family

Cucurbitaceae: Cucurbita gourds, squashes, pumpkin

Rosids-Fabids:
(The Oak and Beech Family)
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Widespread, in tropical to temperate regions of the
Northern Hemisphere
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Trees and shrubs
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Diversity: 670-970 species in 7 genera
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Flowers: Unisexual (monoecious); tepals usually 6 and reduced, inconspicuous; stamens 4-many; carpels 3 (-12), connate, inferior ovary; fruit a nut, associated with a spiny or scaly cupule
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Significant features: Male inflorescences in dangling catkins; female inflorescences in sessile clusters
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Special uses: edible nuts (chestnuts), lumber, tannin, cork; ornamental trees
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Required family