There are 3 subfamilies of Fabaceae, and there is a different floral formula for each subfamily;these are given below as each subfamily is introduced. Fabaceae 02 Family characteristics 02- Fabaceae The family always has a single, simple, superior carpel. The fruit is always a "legume", although there is enormous variation in the fruits of different members of the family.
Remember, you are REQUIRED to know the characteristics of the three subfamilies of Fabaceae. Fabaceae 03 Introduction to Fabaceae 03-Introduction The Fabaceae are a very widely distributed family, common in both the tropics and in temperate regions. Fabaceae 04 Beans! 04-Beans Beans! The seeds of many legumes are beans. Dr. Robertson tells a good story about beans in Lecture. After the grass family (Poaceae), the Fabaceae is the second most important family for humans as cultivated row crops, other types of food plants, ornamental plants, and plants of major importance in natural ecosystems. Taken by K. R. Robertson at Champaign, Illinois. Hands by Scott McKay. Fabaceae 05 Floral formula for Subfamily Mimoisoideae 05-Mimosoideae formula Subfamily Mimosoideae:
Flowers actinomorphic, stamens usually 10 or more, pollen in pollinia, calyx often connate into a tube, corolla often connate into a tube, and filaments often connate into a tube (tube in a tube in a tube). Fabaceae 06 Acacia tree 06-Acacia tree Most members of the Mimosoideae are tropical trees or shrubs. These picturesque Acacia trees on African savannas belong to subfamily Mimosoideae. Fabaceae 07 Bipinnately compound leaves 07-Albizia leaves The leaves of Albizia julibrissin (mimosa tree) are bipinnately compound, as in many Mimosoideae. This species is native to eastern Asia and is commonly cultivated in southern Illinois and other areas with climates warmer than Champaign. While very attractive, this species also invades natural habitats and replaces native species. Photo by K. R. Robertson at Osage Beach, Missouri. Fabaceae 08 Albizia capitate inflorescence 08-Albizia inflorescence The flowers of Albizia julibrissin in dense capitate clusters; note that in this species the center flower (yellow arrow) is larger than the other flowers. Photo by K. R. Robertson at the Arnold Arboretum of Harvard University. Fabaceae 09 Inga flower 09-Inga flower The flowers of Inga are perfect, actinomorphic, and have many stamens, typical of the subfamily. Note the tube in a tube in a tube. Photo by K. R. Robertson from plants cultivated at the Illinois Natural History Survey. Fabaceae 10 Inga flower in longitudinal section 10 Inga flower ls The flowers of Inga are perfect, actinomorphic, and have many stamens, typical of the subfamily. Note single carpel and superior ovary inside the staminal tube. Photo by K. R. Robertson from plants cultivated at the Illinois Natural History Survey. Fabaceae 11 Albizia fruits 11-Albizia fruits The fruits of Albizia julibrissin are flat legumes with several seeds. The fruits persist on the plant after the leaves drop in autumn. Photo by K. R. Robertson at Republic, Missouri. Fabaceae 12 12-Albizia seeds Seeds with U-shaped pleurogram The seeds of Albizia julibrissin, like many other Mimosoid legumes, have a U-shaped pleurogram (mimosoid legumes never have a closed pleurogram). Photo by K. R. Robertson. Fabaceae 13 Acacia inflorescences 13-Acacia inflorescences The genus Acacia is very large is important in many tropical plant communities, and many species are also cultivated in tropical regions. The flowers are usually small and clustered in spherical or cylindrical inflorescences. Photographed at the Massachusetts Horticultural Society Flower Show. Fabaceae 14 Ant Acacia with swollen thorns 14-Ant Acacia Some species of Acacia have a symbiotic relationship with ants. Fabaceae 15 Beltian bodies on Acacia leaves 15-Acacia beltian bodies Beltian bodies, which provide food for ants, are found at the tips of leaflets in the ant acacias. Photograph by H. D. Clarke. Fabaceae 16 Mimosa pucida, sensitive plant 16-Mimosa pucida The sensitive plant (Mimosa pucida) have special structures (pulvinus) at the bases of petioles and leaflets that allow the leaf parts to close up when touched (arrow). Photo by K. R. Robertson at the University of Massachusetts conservatory. Fabaceae 17 Floral formula for subfamily Caesalpinioideae 17-Caesalpinioideae ff Flowers zygomorphic; the sepals, petals, and filaments NOT connate; the "banner" petal is innermost; stamens usually 10 Fabaceae 18 Tree of Cercis canadensis, redbud 18-Cercis habit Most caesalpinoid legumes are tropical or subtropical trees and shrubs. The genus Cercis (redbuds) occurs in temperate regions, and Cercis canadensis is native to Illinois. Photograph by K. R. Robertson on his aunt's farm near Clever, Missouri; the trunks of the trees are "whitewashed" with lime. Fabaceae 19 Leaves of Cercis canadensis, redbud 19-Cercis leaves The leaves of most caesalpinoid legumes are pinnately or bipinnately compound. The "simple" leaves of Cercis canadensis are actually the result of two leaflets that have fused together at the edges.
These leaves are of C. canadensis var. texensis, which has thicker, less pointed leaves than the typical variety. Photo by K. R. Robertson at the National Wildflower Research Center, Austin, Texas. Fabaceae 20 20-Cercis leaves.jpg Dr. Robertson wrote an article about redbuds that was published in Arnoldia, a publication of The Arnold Arboretum. On the cover of the issue was this collection of leaf shapes of different species of Cercis. Each leaf shape was made by laying a thin sheet of paper over a leaf on a herbarium specimen and then rubbing gently with a black crayon. Fabaceae 21 Flowers of Cercis canadensis, redbud 21-Cercis flowers The flowers of Cercis are cauliflorous, that is they arise directly from branches and trunks; the are also produced on small branches. Photo by K. R. Robertson on the campus of the University of Illinois. Fabaceae 22 Flowers, closer view 22-Cercis flowers The flowers of caesalpinoid legumes are zygomorphic, and those of Cercis canadensis are rather "pea-like", with 2 wing petals, 2 keel petals (which are not connate), and 1 banner petal (which is inside the other petals). These flowers are adapted for pollination by insects, such as bees.
This is of Cercis canadensis cv. Pink Charm, which has brighter pink flowers than the typical C. canadensis. Photo by K. R. Robertson at the U.S. National Arboretum, Washington, D.C. Fabaceae 23 Side view of Cercis canadensis flower 23-Cercis flower Side view of a Cercis canadensis flower with all the parts labeled. In Cercis, the sepals are connate, although this is not shown in the floral formula for the subfamily. Photo by K. R. Robertson from plants on the campus of the University of Illinois. Fabaceae 24 Flower of Cercis canadensis in longitudinal section 24-Cercis flower A longitudinal section of a flower of Cercis canadensis with the parts labeled. Note the single carpel with ovules inside. Photo by K. R. Robertson from plants on the campus of the University of Illinois. Fabaceae 25 Fruits of Cercis canadensis 25-Cercis fruits The legume fruits of Cercis canadensis are flat pods that contain several seeds. The pods persist on the branches after the leaves fall off. Photo by K. R. Robertson at Marionville, Missouri. Fabaceae 26 Seeds with closed pleurogram 26-Cassia seeds Many, but by no means all, seeds of caesalpinoid legumes have a closed pleurogram (this subfamily never has a U-shaped pleurogram). Photo by K. R. Robertson from seeds in the Illinois Natural History Survey herbarium. Fabaceae 27 Cassia fasciculata habit 27-Cassia fasciculata While most members of the Caesalpinoideae are woody, Cassia fasciculata (partridge pea) is a herbaceous annual. Note that there are "left" and "right" handed flowers. The banner petals are indicated by the arrows. In Illinois it is often found in prairies. Photo by K. R. Robertson at Cayuga, Illinois. Fabaceae 28 Flower of Cassia fasciculate in longitudinal section 28-Cassia flower l.s A flower of Cassia fasciculata in longitudinal section. Note the banner petal is innermost. The anthers dehisce by terminal pores (arrow). Photo by K. R. Robertson and D. L. Nickrent, University of Illinois. Fabaceae 29 Plant of Caesalpinia pulcherrima 29-Caesalpinia plant Caesalpinia pulcherrima, Pride- of- Barbados, is widely cultivated in tropical and subtropical regions for the colorful red and yellow flowers. The leaves are pinnately compound. Photo by K. R. Robertson at the San Antonio, Texas botanical garden. Fabaceae 30 Raceme of Caesalpinia pulcherrima 30-Caesalpinia flower In this close-up of a raceme of Caesalpinia pulcherrima, you can see the small banner petal (marked with blue arrow) this is the innermost petal. Photo by K. R. Robertson at the San Antonio, Texas botanical garden. Fabaceae 31 Flower of Caesalpinia pulcherrima 31-Caesalpinia flowers This photograph of one flower of Caesalpina pulcherrima shows the small, innermost banner petal that is characteristic of subfamily Caesalpinioideae. Photo by K. R. Robertson at the San Antonio, Texas botanical garden. Fabaceae 32 Tree of Delonix regia, Royal poinciana 32-Delonix regia habit This magnificent tree, Delonix regia (Royal Poinciana), is native to Madagascar but widely cultivated in tropical regions. Photo by K. R. Robertson in Londrina, Parana, Brazil. Fabaceae 33 Flower of Delonix regia, Royal poinciana 33-Delonix flower The bright red flowers of Delonix regia are 3 to 4 inches across. The banner petal (which is innermost) has a white area to attract pollinators. Photo by K. R. Robertson in Londrina, Parana, Brazil. Fabaceae 34 Fruits of Gymnocladus dioicus 34-Gymnocladus fruits A common tree, but in the wild and cultivated (such as to the east of Mumford hall) is Gymnocladus dioica (Kentucky coffee tree). The fruits contain several large seeds, and the green material around the seeds is rich in saponins, the same kind of compounds that make soap lather. Photo by K. R. Robertson at the Arnold Arboretum of Harvard University. Fabaceae 35 Fruits of Tamarindus indica 35-Tamarindus indica The tamarind (Tamarindus indica) has been cultivated in tropical and subtropical regions for a long time; perhaps it is native to India. The brown pulp inside the fruits is eaten fresh and used as an ingredient in refreshing drinks, curries, chutneys, and other seasonings, such as Worcestershire sauce. Photo by K. R. Robertson in Trelawny, Jamaica. Fabaceae 36 Floral formula for subfamily Faboideae 36-Faboideae ff Subfamily Faboideae has zygomorphic flowers with 2 wing petals, 2 keel petals (connate along their lower margins), and 1 banner petal (which is the outermost petal). There are 10 stamens, and in many genera they are diadelphous (9 connate, 1 free). This is an extremely large subfamily, and only a few examples are given below; more are presented in lecture.
NOTE: Sometimes subfamily Faboideae is called "Papilionoideae"; regardless of which Latin name is used, this subfamily is commonly called the "Papilionaceous" legumes". Fabaceae 37 Herbaceous habit of Lathyrus 37-Lathyrus habit "Papilionaceous" legumes can be herbaceous, shrubs, or trees and occur from the tropics to cold-temperate regions. The genus Lathyrus is commonly called "sweet pea" and the flowers are good examples of this subfamily. NOTE that the banner petal is outside the wing and keel petals. Photo by D.L. Nickrent at Placerville, California. Fabaceae 38 Papilionaceous flowers of Lathyrus 38-Lathyrus flowers In these flowers of Lathyrus latifolius (everlasting pea), you can easily see the banner petal and the two wing petals. The keel petals are enclosed by the wing petals. Again note that the banner petal is outside the wing and keel petals. Photo by K. R. Robertson, Cass County, Illinois. Fabaceae 39 Lathyrus flower in longitudinal section 39-Lathyrus flowers l.s In this longitudinal section of a flower of Lathyrus latifolius, you can clearly see the diadelphous stamens and the banner, wing, and keel petals, with the banner petal being outermost. Photo by K. R. Robertson. Fabaceae 40 Lathyrus flower in longitudinal section 40-Lathyrus flowers l.s In this longitudinal section, the tube of the diadelphous stamens has been cup open to show the single carpel. The yellow arrow points to the free top stamen. Photo by K. R. Robertson. Fabaceae 41 Field of Glycine max, soybean 41-Glycine max field One of the most abundant plants in Illinois is soybean, Glycine max, which is a papilionaceous legume. However, this photo was not taken in Illinois — note the palm tree in the background! Photo by K. R. Robertson, Palmeira, Parana, Brazil. Fabaceae 42 Flowers of Glycine max 42-Glycine flowers The flowers of Glycine max are quite small and are produced at the tips of the young stems. Photo by K. R. Robertson from plants cultivated in Champaign, Illinois. Fabaceae 43 Flower of Glycine max in longitudinal section 43-Glycine flower l.s Although small, the flowers of Glycine max have the same structure as other papilionaceous legumes. Photo by K. R. Robertson from plants cultivated in Champaign, Illinois. Fabaceae 44 Fruits of Glycine max 44-Glycine fruits The soybean produces these familiar fruits, each of which contains several seeds. Photo by K. R. Robertson, Champaign County, Illinois. Fabaceae 45 Pueraria lobata, kudzu, invading landscape 45-Pueraria lobata Not all papilionaceous legumes are nice. This is Pueraria lobata (kudzu vine), a native of China and Japan that has become a serious invasive species in the southeastern United States (an now even parts of Illinois). The perennial, partially woody vines grow extremely rapidly and cover the ground and climb trees completely choking out native vegetation. Photo by K. R. Robertson at Chapel Hill, North Carolina. Fabaceae 46 Peanut plant in flower 46-Arachis hypogea The flower of Arachis hypogea, peanut, are yellow and look like typical papilionaceous legumes; the flowers are pollinated by bees. Photo by D. S. Seigler, University of Illinois. Fabaceae 47 Peanut plant in fruit 47-Arachis hypogea After plants of Arachis hypogea, peanut, have flowered, the pedicel of the flower greatly elongates and curved downward. Soon, the ovary is pushed underground, where the familiar peanut fruits develop. Photo by D. S. Seigler, University of Illinois. Fabaceae 48 Habit of Petalostemum purpureum 48-Petalosemum habit Several papilionaceous legumes are found in the tallgrass prairie, including Petalostemum purpureum, purple prairie clover. To see more images of prairie legumes, go to Dr. Robertson's prairie web site ( http://www.inhs.uiuc.edu/~kenr/tallgrass.html) and click on "Prairie Plants." Photo by K. R. Robertson at the prairie restoration, College of DuPage, Glen Ellyn, Illinois.