Fabids
Spring 2012

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 Myrtales
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 taxa: Euphorbia

• 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 taxa: Populus, Salix

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

Violaceae: Viola
-mostly herbs, some shrubs
-flowers zygomorphic
-lower petal spurred
-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; 3 subfamilies but 1 is not monophyletic
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Special uses: Many!! Beans, peas, peanuts, soybean, clover, ornamentals (Mimosa, Bauhinia); lumber, dyes, resins
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Required taxa: Glycine, Trifolium, Mimosa, Cercis, Gleditsia and the three subfamilies

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 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 pinnately or twice pinnately compound
Fls + weakly zygomorphic, upper petal usually innermost; petals distinct
Stamens 5 or 10, distinct
Papilionoideae
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

-woody or herbaceous
-often armed (with prickles)
-leafstalk without glands
-flowers in heads or rarely racemes or spikes
-stamens 10 or fewer

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

Fabaceae : “Caesalpinioideae”: Cercis
-unarmed
-leaves simple, palmately veined
-flowers clustered, appearing before leaves
-corolla rose to pink-purple
Cercis canadensis - redbud

-armed (with thorns)
-leaves 1- or 2-pinnate
-flowers small, unisexual or bisexual
-staminate inflorescences catkin-like, pendent
-fertile inflorescences with bisexual or carpellate flowers
Honey locust

Fabaceae – Subfamily Faboideae

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

Petals unequal:
• banner
• wings
• keel
Crotalaria spectabilis showy rattlebox

Lathyrus sweet-pea
Digital Flowers

-leaves pinnately 3-foliolate
-inflorescence a raceme
-stamens diadelphous
-seeds few per pod

-leaves palmately (or pinnately) foliolate with usually 3 leaflets
-inflorescences racemose but often appearing head-like
-stamens diadelphous
-fruits enclosed by the persistent corolla
-seeds 1-6 per pod

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 taxa: Rubus, Prunus

-shrubs, often prickly
-leaves pinnately compound
-ovary superior
-hypanthium + globose and fleshy, contracted at the mouth
-carpels numerous
-fruit an achene

-herbaceous to shrubby, usually with prickles
-leaves often compound with 3 to 7 leaflets
-carpels usually numerous, borne on an elongate receptacle
-fruit a drupelet, forming an aggregate fruit (blackberries and raspberries)
*required for recognition

-trees or shrubs
-bark with prominent horizontal lenticels
-ovary superior
-carpel solitary
-fruit a drupe, endocarp stony
*required for recognition

-trees with simple leaves
-ovary inferior, with
5 carpels
-mature carpels papery or softly leathery
-fruit a pome, lacks stone cells

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
-connate stipules enclosing the terminal buds
-leaves with entire margins
-flowers minute, borne inside the syconium
-wasp-pollinated

Moraceae – The Fig and The Fig Wasp

Rosids-Fabids:
(The Elm Family)
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Widely distributed; maximal diversity in temperate regions of N. Hemisphere
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Trees with alternate, 2-ranked leaves
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Diversity: 35 species in 6 genera
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Flowers: Small, inconspicuous; tepals 4-9; stamens
4-9; carpels 2, connate, superior ovary; fruit a samara or nutlet, seeds flat
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Significant features: Leaves simple with pinnate venation, margins simply or doubly serrate, blade base asymmetrical; endosperm of a single layer
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Special uses: Elms provide lumber; some trees used as ornamentals
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Family not required

Ulmaceae: Ulmus

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 taxa: family only

Cucurbitaceae: Cucurbita
-trailing herbs
-leaves large, cordateangled or lobed
-flowers large, solitary in axils
-corolla campanulate, deeply
5-lobed
-ovaries and fruits smooth or hairy, not prickly
-fruits large, with a firm rind
-gourds, squashes, pumpkin

Rosids-Fabids:
(The Begonia Family)
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Widely distributed in the tropics and subtropics
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Herbs or soft woody shrubs
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Diversity: ca. 1,400 species in 2 genera (all but one species in Begonia)
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Flowers: Unisexual; tepals petaloid, 2-10 but usually
4 in 2 whorls (staminate) and 5 in 1 whorl (pistillate); carpels usually 3, connate; inferior ovary; fruit a loculicidal capsule, usually winged
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Significant features: Soft herbs, typically of shaded habitats; stigmas elongated, twisted, yellow, papillose
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Special uses: primarily ornamentals
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Family not required

Begoniaceae: Begonia
Carpellate Flowers Staminate Flowers
-winged ovaries

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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Family not required

• Bark pale to dark but scaly or furrowed
• Buds clustered at twig tips, ovate
• Leaves lobed or unlobed
• Male flowers in drooping catkins
• Cupule saucer-like or cup-shaped
• Nut circular in cross-section

• Bark light gray, smooth
• Buds solitary at twig tips, slender and acute
• Leaves unlobed, strongly straight-veined
• Male flowers in a rounded head
• Cupule with 4 valves
• Nut compressed or triangular

Rosids-Fabids:
(The Birch Family)
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Widespread, in temperate to boreal regions, primarily of the northern hemisphere
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Trees or shrubs; leaves doubly serrate
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Diversity: 140 species in 6 genera
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Flowers: Unisexual (monoecious); tepals (0-) 1-4 (-6), highly reduced; stamens 1-4; carpels 2, connate, inferior ovary; fruit an achene, nut or 2-winged samara
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Significant features: Flowers in erect (female) or pendant (male) catkins (aments); staminate and carpellate flowers in separate inflorescences
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Special uses: hazel nuts edible; lumber, shade trees, ornamentals
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Family not required

• Outer bark often separating in thin sheets
• Carpellate and staminate flowers both in bracteate catkins
• Carpellate catkins ovoid to cylindrical, with 2-3 flowers per bract and the bracts papery (bracteate dichasia)
• Staminate flowers 3 per bract; stamens 2, bifid

Rosids-Fabids:
(The Walnut and Hickory Family)
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Widespread from tropical to temperate regions
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Aromatic trees; leaves pinnately compound or trifoliolate, usually alternate and spiral
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Diversity: 59 species in 8 genera
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Flowers: Unisexual (monoecious or dioecious); tepals
0-4, inconspicuous; stamens 3-many; carpels usually
2, connate, ovary inferior; fruit a nut or nutlet
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Significant features: Fruit often associated with bracts or bracteoles that form an outer “husk”
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Special uses: fruits of hickories (Carya) and walnuts
(Juglans) are eaten; walnut and hickory are valued for their lumber; some ornamentals
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Family not required

• Twigs with chambered pith
• Leaflets all about the same or the median ones largest
• Staminate catkins sessile, solitary
• Nut with an indehiscent, usually rough or furrowed husk

• Twigs with solid pith
• Apical leaflets largest
• Staminate catkins sessile or pedunculate, in clusters
• Nut with a dehiscent or partially dehiscent, often smooth husk