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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.

Basal eudicot families covered in class:

Ranunculales:

Papaveraceae (Papaveraceae Family)

Ranunculaceae (Buttercup Family)

 

Order: Ranunculales

*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 manual.

Argemone albiflora White Prickly-Poppy; Sanguinaria canadensis (patch), (individual), (2), (flower closeup), (2), (another patch), (2), (fruit) Bloodroot; Stylophorum diphyllum, (flower closeup), (2), (3), (fruit) Wood Poppy

(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) Thimbleweed; Aquilegia canadensis, (flower), (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 canadensis, (2), (3), (individual), (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) Spreading Globeflower

Berberidaceae: Caulophyllum 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

Menispermaceae: Menispermum canadense (male), (male closeup), (female), (female closeup), (fruits) Moonseed

 

*Order: Proteales

Proteales is an order with an odd assortment of plants that have sometimes been misplaced in other groups. Proteaceae are showy, usually shrubby plants predominently found in the southern hemisphere, Platanaceae are wind-pollinated trees (Sycamore) of the northern hemisphere, whereas Nelumbonaceae (Water Lotus) are aquatic and superficially similar to Waterlilies (Nymphaeaceae), a group to which they were historically thought to be related. However, all Proteales, including Water Lotuses have tricolpate pollen, clearly indicating they are eudicots, and DNA evidence strongly supports them as each others' relatives despite their morphological dissimilarity.

Nelumbonaceae: Nelumbo lutea, (habit), (fruit) American Water Lotus, Nelumbo hybrid Hybrid Water Lotus

Platanaceae: 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

 

Order: Buxales

Buxaceae: Pachysandra procumbens (inflorescence) Allegheny Spurge

 

 

 

 

 



 

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