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The Eudicots, or "true" dicots, form a monophyletic group. Members share the morphological synapomorphy of tricolpate pollen or derivitives thereof. At the base of the Eudicots are lineages that tend to show some ancestral characteristics; these lineages are known as the Basal Eudicots. They often have numerous stamens, separate carpels, and other characteristics more typical of the Basal Angiosperm lineages, and they have flower parts in multiples of 3, 4, or 5. Some of these plants were once grouped along with the Basal Angiosperms by traditional taxonomists for good reason, although molecular evidence now supports their placement with other true dicots. One of the most bizarre Basal Eudicots is Nelumbo, the Water Lotus genus. Although they look superficially similar to water-lilies, one of the basal-most flowering plants, Lotuses are actually much more closely related to Sycamore trees! Basal eudicots probably form a grade of branches and are, thus, probably paraphyletic.
Purple denotes orders containing families covered in class; green denotes orders photographically represented but not covered in Biology 414. Click on the tree to skip directly to a given order.
Basal eudicot families covered in class: Ranunculales: Berberidaceae (Barberry Family) Papaveraceae (Poppy Family) Ranunculaceae (Buttercup Family) Proteales: Nelumbonaceae (Water Lotus Family) Platanaceae (Sycamore Family)
Berberidaceae: (Barberry Family) Identification characteristics: Berberidaceae have 4 to 6 sepals which are often caducous (soon 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 a few taxa have typical longitudinal dehiscence. There is one superior ovary apparently formed from one carpel (one locule). The fruit is usually a berry, but occasionally may be a pyxidium (a capsular structure that opens via a lid). Some Berberidaceae are shrubs, but most in our range are herbaceaous. 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 barberry species. Caulophyllum thalictroides Blue Cohosh- The foliage of Blue Cohosh is dark purple when it first emerges in early spring. Caulophyllum thalictroides Blue Cohosh- Blue Cohosh produces blue seeds that resemble berries later in the summer. Caulophyllum thalictroides Blue Cohosh- Caulophyllum, like most Berberidaceae, has anthers that open via flaps to release pollen. Diphyllea cymosa Umbrella Leaf (in fruit)- This species is native only to the central and southern appalachian region. Jeffersonia diphylla Twinleaf- Twinleaf flowers open before the leaves are fully grown and unfolded. Jeffersonia diphylla Twinleaf- The flowers of Jeffersonia are extremely ephemeral, with a population often only blooming for one or two days in spring. Jeffersonia diphylla Twinleaf- Notice the long, widely splayed flaps that have flipped up to release pollen from the anthers. Jeffersonia diphylla Twinleaf- The "twin" leaves of Jeffersonia are all basal. This species is usually found on limestone derived soils or floodplains. Jeffersonia diphylla Twinleaf- The fruit of Jeffersonia, known as a pyxidium, is an assymetric capsule with a circumscissle lid. Podophyllum peltatum Mayapple (plant)- Mayapple forms large colonies through a creeping root system. The flowers eventually produce an edible berry. Podophyllum peltatum Mayapple (flower closeup)- Unlike other Berberidaceae, Podophyllum anthers release pollen through longitudinal slits. Menispermum canadense Moonseed (male)- Moonseed vines are dioecious, with only male or female inflorescences on a given plant. Menispermum canadense Moonseeds (male, closeup)- The numerous stamens in Menispermum show affinities to related families like Ranunculaceae. Menispermum canadense Moonseed (female)- The curved seed inside the black fruit of Moonseed resembles a crescent moon. Menispermum canadense Moonseed (female, closeup)- The female flowers start with 3 stalked carpels; usually all but one abort. Identification characteristics: Papaveraceae have 2 sepals which are soon caducous. Most have 4 petals that are radially symmetric, but multiples of 4 also occur. Members of the lineage formerly separated as Fumariaceae have highly zygomorphic 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 that may appear to be formed from 2 to many carpels. Papaveraceae have alternate leaves that may be simple to deeply dissected, and most members 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: Members of the former Fumariaceae are included in Papaveraceae your manual. Sanguinaria canadensis Bloodroot- The red juice inside the rhizome of Bloodroot was once used for dye. The flowers close every night until pollinated. Sanguinaria canadensis Bloodroot- Another name sometimes used for Bloodroot is Red Puccoon. Sanguinaria canadensis Bloodroot- The flowers of Bloodroot drop their 2 sepals as the flowers open, and the 8 petals drop very soon after being pollinated. Sanguinaria canadensis Bloodroot- The rhizome of Bloodroot can spread, forming large clumps. The seeds are ant dispersed. Sanguinaria canadensis Bloodroot- The ovary of Bllodroot swells into an ellipsoidal capsule, which drops numerous seeds in early summer. Stylophorum diphyllum Wood Poppy- This species is found in woods in western PA. It resembles the introduced, smaller flowered Celadine (Chelidonium). Stylophorum diphyllum Wood Poppy- Like Bloodroot, the seeds of Stylophorum have an elaisome, an appendage eaten by the ants which disperse them. Stylophorum diphyllum Wood Poppy- The fuzzy capsule of Wood Poppy resembles the unopened flower bods of other species of Poppy. Adlumia fungosa Allegheny Vine- This biennial vine produces flowers that look like slender Bleeding Heart flowers. The ferny leaves are tendril-like at the tips. Corydalis sempervirens Pale Corydalis- Pale Corydalis may have pink to white flowers. Although a delicate biennial, it often grows on dry rocks. Dicentra canadensis Squirrel Corn- The yellow kernels produced from the root system of this species are sometimes eaten by squirrels and other rodents. Dicentra cucullaria Dutchman's Breeches- The flowers resemble pairs of pantaloons hanging upside down. The roots produce pink to white kernels. Dicentra cucullaria Dutchman's Breeches- Leaves of Dutchman's Breeches and Squirrel Corn disappear until the following spring soon after flowering. Dicentra cucullaria Dutchman's Breeches- Large bees are the primary pollinators of Dutchman's Breeches, although many insects chew through the spurs to rob nectar. 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 below 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 below). Occasionally, Ranunculaceae are dioecious (see Clematis virginiana and Thalictrum dioicum) and/or wind pollinated (T. dioicum). Ranunculaceae bloom almost exclusively in spring and make up a significant portion of the spring flora in the eastern U.S. Actaea alba White Baneberry- Also know as Dolls' Eyes, the poisonous white berries have thicker stalks than the red berries of the similar Red Baneberry. Actaea alba White Baneberry- The flowers only have a single whorl of perianth (sepals) surrounding the superior ovary. Anemonella thalictroides Rue Anemone- The sessile, ternately compound leaves of this species give the appearance of a whorl of six leaves. Anemonella thalictroides Rue Anemone- This species is often included in the Meadow Rue genus, Thalictrum. Anemonella thalictroides Rue Anemone- The number of sepals varies from flower to flower in this species. Anemone quinquefolia Wood Anemone- The white sepals of Wood Anemone only open in bright light. Anemones have no petals. Anemone virginiana Thimbleweed- The achenes of Thimbleweed are crowded on a thimble-like head. Anemone virginiana Thimbleweed- The numerous stamens and numerous separate carpels are typical Ranunculaceae and Basal Eudicot traits. Aquilegia canadensis Wild Columbine (plant)- Wild Columbine seems to grow best in limestone crevices, although it is found in a variety of habitats. Aquilegia canadensis Wild Columbine (flower)- The red sepals of the flower are as colorful as the spurred petals of this hummingbird favorite. Caltha palustris Marsh Marigold- Marsh Marigold often grows in standing water, where it dies down for the summer soon after flowering. Cimicifuga racemosa Black Cohosh- The bloom spikes of Black Cohosh can reach well over 6 feet. Clematis occidentalis Purple Clematis- The genus Clematis is unusual for Ranunculaceae in having opposite leaves and having many viney species. Clematis occidentalis Purple Clematis- Clematic occidentalis usually grows out of ledges and slopes in limestone-based soils. Clematis virginiana Virgin's Bower (male flower)- Although small, the numerous flowers of this Clematis put on a show to rival its garden relatives. Coptis groenlandica Goldthread- Goldthread is named for its golden underground runners. The ovaries are stalked and become follicles at maturity. Delphinium tricorne Dwarf Larkspur- The spurred, zygomorphic flowers of Dwarf Larkspur are composed of colorful sepals and petals. Hepatica nobilis (Hepatica americana) Round-Lobed Hepatica- This species comes in a range of colors from white to pink to dark purple. Hepatica americana Round-Lobed Hepatica- Now considered conspecific with Sharp-Lobed Hepatica, this variety is more common in Centre County. Hepatica americana Round-Lobed Hepatica- Hepatica in Latin means liver, referring to the three lobed, brown blotched leaves of this genus. Hepatica americana Round-Lobed Hepatica- Hepatica is one of the earliest woodland wildflowers to bloom each spring in PA, often starting in March. Hydrastis canadensis Goldenseal- The stamens put on most of the floral show for this plant, which is overcollected because of its value in folk medicine. Isopyrum biternatum False Rue Anemone- Isopyrum has follicular fruits and alternate leaves, distinguishing it from Rue Anemone. Ranunculus fascicularis Early Buttercup- As its name suggests, this native buttercup is often the first of its kind to bloom in the spring. Thalictrum dioicum Early Meadow Rue (female)- Male flowers and female flowers are borne on separate plants. They are wind pollinated. Thalictrum dioicum Early Meadow Rue (female inflorescence)- The tepals subtenfing the apocarpous ovaries are very inconspicuous. Thalictrum dioicum Early Meadow Rue (male inflorescence)- The anthers of this species dangle in the wind, facilitating pollen dispersal. Thalictrum pubescens Tall Meadow Rue- The flowers of Tall Meadow Rue attract insects not with petals or sepals, but with the showy white stamens. Trollius laxus Spreading Globeflower- This plant, rare in PA, has showy sepals and many inconspicuous orange-yellow petals under the stamens.
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, 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 arrangements. Nelumbo lutea American Water Lotus- The large, peltate leaves of Nelumbo are waxy and always appear clean, making them a symbol of purity in Buddhist culture. Nelumbo lutea American Water Lotus- Both the flowers and habit of Nelumbo superficially resemble those of the unrelated Water Lilies. Nelumbo lutea American Water Lotus- The gynoecium of Nelumbo is very distinct from those found in Water Lilies and in all other flowering plant families. 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 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. |
