The Eudicots, or "true" dicots,
form a monophyletic group. Members share the morphological synapomorphy
of tricolpate pollen or derivitives thereof (the ancestral state of angiosperms, retained by monocots and basal angiosperm lineages, is monosulcate or monoporate pollen). Although most eudicots have flower parts in multiples of 4 or 5, lineages of Eudicots that branched off before the Rosid/Asterid/Caryophyllales split sometimes show ancestral floral characteristics;
these lineages are collectively known as the Basal Eudicots, although they are a paraphyletic group of successive branches (only 2 shown below). They often have
numerous stamens, separate carpels, and other characteristics
more typical of the Basal Angiosperm lineages, and they may have flower parts in multiples of 6 or indeterminate as well as 4 or
5. Some of these plants were once grouped along with the Basal
Angiosperms by traditional taxonomists for these reasons, although
molecular evidence now supports their placement with other true
dicots as does their tricolpate pollen.
families covered in class:
Berberidaceae (Barberry Family)
Papaveraceae (Papaveraceae Family)
Ranunculaceae (Buttercup Family)
Nelumbonaceae (Lotus Family)
Platanaceae (Sycamore Family)
*Berberidaceae: (Barberry Family)
Identification characteristics: Berberidaceae have 4 to 6 sepals which are often
caducous (deciduous when the flower opens); thus, open flowers
of Berberidaceae may look sepal-less, but the sepals will be
present on flower buds. Petals are 6 or 8 or 12, rarely more
in multiples thereof. Stamens are usually 6, 8, or 12, but sometimes
a few extra may be present. The anthers usually open by two flaps
that open from the base, but Podophyllum retains typical longitudinal
dehiscence. There is one superior ovary formed from
one carpel (one locule). The fruit is usually a berry (exception in Jeffersonia is a pyxidium- a capsular structure that opens via a lid).
Many Berberidaceae are planted as ornamental shrubs, but native species in the E. U.S. are all herbaceous except the rare Berberis canadensis.
Interesting stuff: Berberidaceae are spring and early-summer bloomers in our area.
Many are poisonous. Shrubs such as Nandina, Mahonia,
and Berberis are often planted as ornamentals. European
barberry was once widely planted and escaped in the U.S., but
it serves as the alternate host of wheat stem rust, and massive
removal projects were undertaken last century. Native barberry
is now rare in many places due to this eradication project and
competition from other introduced, invasive species.
thalictroides (habit 1), (habit 2),
(flower closeup), (yellow form), (2), (3) Blue Cohosh; Diphyllea cymosa (inflorescence), (2), (flower), (2), (in fruit), (2) Umbrella Leaf; Jeffersonia
diphylla (habit in flower), (flowers), (flower closeup), (habit),
(fruit) Twinleaf; Podophyllum peltatum (flower closeup)
Mayapple; Vancouveria hexandra White Inside-out Flower
*Papaveraceae: (Poppy Family)
Identification characteristics: Papaveraceae have 2 sepals which are soon caducous.
Most have 4 petals that are radially symmetric, but multiples
of 4 also occur. Stamens are numerous in the typical members of the family. Members of the lineage formerly separated as Fumariaceae have highly zygomorphic
or bis-bilaterally symmetric (2 unequal planes of symmetry- see Adlumia and Dicentra) flowers, the petals often being somewhat connivent. Stamens in
typical Papaveraceae are very numerous (6, diadelphous, grouped
in two sets of three in Fumarioids). There is one superior ovary. Papaveraceae
have alternate leaves that may be simple to deeply dissected,
and members outside of Fumariodeae have white to colorful sap.
Interesting stuff: Members of Papaveraceae (including Fumariaceae) produce isoquinone
alkaloids that are often very toxic or otherwise induce profound
physiological effect. The most economically important example
by far is the opium poppy (Papaver somniferum), extracts
of which are the basis for opium, morphine, and other derived
drugs. The seeds of P. somniferum, which contain only
trace amounts of alkaloids, are the poppy seeds commonly used
in baked goods. Many Papaveraceae are colorful garden ornamentals. Note: Fumariaceae are listed as a separate family in your
Argemone albiflora White Prickly-Poppy; Sanguinaria
canadensis (patch), (individual),
(2), (flower closeup), (2), (another patch), (2), (fruit)
closeup), (2), (3), (fruit) Wood
(subfamily Fumarioideae): Adlumia fungosa Allegheny Vine; Corydalis flavula (flower, side), (front), (population) Yellow Fumewort; C.
sempervirens Rock Harlequin; Dicentra
canadensis Squirrel Corn; D. cucullaria (flowers closeup), (habit),
(more habit), (3) Dutchman's Breeches; D. eximia Wild Bleeding-Heart
*Ranunculaceae: (Buttercup Family)
Identification characteristics: Floral morphology in Ranunculaceae is highly variable,
and a suite of characters must be examined for identification.
Species are predominantly herbs (often vines in Clematis).
They have alternate (or basal) leaves (opposite in Clematis).
Usually flowers are radially symmetric (see Delphinium tricorne for an exception). Sepals are usually 5 (4 in Clematis, indeterminant in many others). They are often
petaloid and are the pollinator attractant when petals are absent.
Sometimes a combination of sepals and petals make up the colorful
floral display (see Delphinium). Petals are usually 5
when present, and may have nectar glands at their base, sometimes
held within an elaborated spur (see Delphinium and Aquilegia canadensis below for examples). Stamens are
numerous in all cases. Ovaries are superior and apocarpous (separate),
sometimes 5, often more numerous. An important characteristic
in keys is whether each carpel contains one or numerous ovules,
and thus forms an achene or follicle, respectively. Some multi-ovule
carpels occasionally form berries rather than follicles.
Interesting stuff: Like other Ranunculalean families, Ranunculaceae often produce
very toxic alkaloids. The family provides numerous ornamentals,
such as Larkspurs (Delphinium), Monkshoods (Aconitum),
Columbines (Aquilegia), and Windflowers (Anemone).
Some Ranunculaceae have reduced perianth parts and rely instead
on brightly colored stamens to attract pollinators (see Hydrastis
canadensis and Thalictrum pubescens). Occasionally,
Ranunculaceae are dioecious (see Clematis virginiana and Thalictrum dioicum) and/or wind pollinated (T. dioicum).
Most Ranunculaceae bloom in spring and make up
a significant portion of the spring flora in the eastern U.S.
Examples: Aconitum columbianum Western Monkshood; A. reclinatum Trailing Monkshood; Actaea alba, (inflorescence)
(infructescence) White Baneberry; Anemonella
(Thalictrum) thalictroides, (2), (3), (4), (pink form)
Rue Anemone; Anemone multifida Cut-leaved Anemone; A. quinquefolia Wood Anemone; A. virginiana, (flower closeup)
(flower 2), (flower 3) Wild Columbine; Caltha palustris Marsh Marigold; Cimicifuga racemosa Black Cohosh; Clematis occidentalis, (flower) Purple
Clematis; C. ochroleuca Curlyheads; C. pitcheri, (flower) Texas Leatherflower
(photo from TX), C. viorna Leatherflower; C.
virginiana (male) Virgin's Bower; Coptis groenlandica, (closer) Goldthread; Delphinium carolinianum (2), (3) Prairie Larkspur; D.
tricorne (2), (3), (flower) Dwarf Larkspur; Hepatica
americana (white and pink), (purple and white),
(pale lavender), (purple), (white)
Round-Lobed Hepatica; H. acutiloba (2), (3), (4), (5) Sharp-Lobed Hepatica; Hydrastis
(closeup), (2), (fruit),
(closer) Goldenseal; Isopyrum
biternatum False Rue Anemone; R. abortivus Littleleaf Buttercup; Ranunculus
fascicularis Early Buttercup; R. ficaria Lesser Celandine; Thalictrum clavatum Mountain Meadow Rue; T.
dioicum (female), (close), (male inflorescence)
Early Meadow Rue; T. pubescens, (flower closeup)
Tall Meadow Rue; Trautvetteria caroliniensis (2), (3) Tassel-rue; Trollius
laxus, (flower), (ssp. albiflorus)
canadense (male), (male closeup),
closeup), (fruits) Moonseed
*Nelumbonaceae: (Water Lotus Family)
Identification characteristics: The most likely family to be confused with Nelumbonaceae
is the unrelated Nymphaeaceae.
Both families are aquatics with roundish leaves on long petioles
and numerous tepals and stamens. Many differences exist between
the two families, however. Despite the fact that most traditional
taxonomic treatments tentatively grouped Nelumbo within
the Nymphaeles, it came as no surprise that it actually belongs
within the eudicots. Aside from having a very different gynoecial
structure from Nymphaeales, Nelumbo also had tricolpate
pollen like a good eudicot should (very much different from the
"primitive" monosulcate pollen found in Nymphaeales
and other basal angiosperms). The leaves of Nelumbo are
large, orbicular, peltate, and always held well above the water
surface. The gynoecium and fruit of Nelumbo are particularly
unusual, consisting of numerous distinct carpels imbedded in
a large, obconic, flat-topped receptacle.
Interesting stuff: Only two extant species of Nelumbo exist: Nelumbo
lutea (below), which is native to the northern midwest of
the United States, and Nelumbo nucifera, the Sacred Lotus
of Asia. The Sacred Lotus is an important symbol of purity in
Buddhism. Both lotus species and hybrid cultivars are widely
planted as ornamentals in water gardens, and lotus seeds are
sometimes roasted and eaten. The leaves are coated by a waxy
substance that prevents mud from adhering to the leaf surface
upon emergence and causes water to bead up in droplets on the
leaf. This wax has even bee extracted and used in some types
of paints and sealants as a waterproofing agent. The pitted seed
receptacles of lotuses are often dried and sold for use in floral
Nelumbo lutea, (habit), (fruit)
American Water Lotus, Nelumbo hybrid Hybrid Water Lotus
*Platanaceae: (Sycamore Family)
Identification characteristics: The most distinctive feature of the family, containing
only the tree genus Platanus, is the mottled bark, which
flakes off leaving various shades of greenish, yellowish, and
brown on the lower trunk and whitish on the upper trunk and branches. The lateral buds are surrounded by the petiole. The plants
are monoecious, and the flowers are small, inconspicuous, and
wind-pollinated. The flowers are borne in dense, globular heads
as the trees leaf out in early spring. Sepals are very minute
and are variable in number, ranging from 3 to 7. Male flowers
have the same number of petals, but these are lacking in female
flowers. The anther connectives are elaborated into a long, peltate
structure. Female flowers produce a 5 to 9 parted apocarpous
gynoecium that will mature to separate achenes, each subtended
by long bristles. These thin achenes are aggregated into a conspicuous
globose cluster about 1 to 1.5 inches thick.
Interesting stuff: Sycamore trees usually occur along streams, rivers, and bottomland
floodplains where their massive form and ghostly white upper
bark make them a conspicuous and easily-identified tree. They
are also commonly planted as street and shade trees, although
their messy, ever-flaking bark is disdained by many.
Platanus occidentalis (branch with male and female inflorescences), (female inflorescence),
(male inflorescence), (male
inflorescence dehiscing wind-borne pollen) American Sycamore
Proteaceae: Embothrium coccineum Chilean Firebush
Buxaceae: Pachysandra procumbens (inflorescence) Allegheny Spurge