伞形科Apiaceae.doc

伞形科Apiaceae1-Floral formula Here is the floral formula for the Apiaceae or Umbelliferae. The flowers may be perfect, but more often they are imperfect, and the plants are then monoecious, dioecious, or polygamous. The sepals are very tiny in the Apiaceae, the petals are often curved, the 5 stamens within a flower unfold at different times, the style bases enlarge to form the stylopodium that secretes nectar, and the ovary is inferior. 2-Introduction This family is correctly called either the Apiaceae or the older Umbelliferae. In the modern context, the family includes a group of plants formerly separated as the Araliaceae. Dr. Stephen Downie has done considerable research on the systematics of this family using molecular methods. Members of the Apiaceae occur worldwide. There are about 460 genera and 4,250 species. Most plants of this family that occur in temperate regions are herbaceous, while those in the tropics are shrubs and trees. 3-Biennial plants Many members of the Apiaceae in temperate regions are herbaceous plants annuals, biennials, and perennials. Many species are biennials, like carrots, that produce leaves and an underground root the first year, then flower, set seed, and die during the second year 4-Hollow stems Most members of the Apiaceae have hollow stems. The stems also have oil tubes that contain fragrant essential oils. This is Anethum graveolens , dill. 5-Leaves Many members of the Apiaceae have pinnately compound leaves and sheathing leaf bases. The leaves, as well as the stems, also have oil tubes that contain fragrant essential oils. This example is Anethum graveolens, dill. 6-Daucus carota A common plant along roadsides in Illinois is Queen Annes Lace, Daucus carota. This is the same species as the cultivated carrot. This species is a biennial, and these are second year plants that are producing flowers 7-Umbel inflorescence The basic inflorescence type in the Apiaceae is an umbel. In Daucus carota, it is a compound umbel. Note the bracts below the inflorescence. 8-Flowers This is a simple umbel in wild parsnip, Pastinaca sativa. Note the large stylopodium, which is an enlarged style base that secretes nectar. 9-Developing fruits The ovary is inferior, and this photo shows the ovaries developing into fruits in wild parsnip, Pastinaca sativa. 10-Schizocarps The fruit of the Apiaceae is a small schizocarp that splits apart into 2 mericarps. Connecting the schizocarps is the carophore. Each mericarp contains oil tubes. This example is Zizia aurea, Golden Alexanders. 11-Spices Many spices are the schizocarps and mericarps of different species of Apiaceae. The oil tubes contain the flavorful and aromatic essential oils. In this photo are: fennel, cumin, dill, and celery seed. 12-Osmorhiza habit A common spring woodland wildflower in Illinois is Osmorhiza longistylis, Sweet Cicely or Anise Root, the latter because of the anise or licorice fragrance. 13-Osmorhiza inflorescence The inflorescence of Osmorhiza longistylis is a simple umbel. The flowers are imperfect and the plants monoecious. Note the large stylopodium on the female flowers. The petals have fallen off the female flowers in this photo. 14-Osmorhiza flowers Female and male flowers of Osmorhiza longistylis. Note the inferior ovary in the female flowers; also note the stylopodium at the top of the ovary in the female flowers. (Male flowers also have a stylopodium, but you cannot see it in this photograph.) 15-Zizia aurea A member of the Apiaceae found both in prairies and in woodlands is Zizia aurea, Golden Alexanders. 16-Zizia inflorescence The inflorescence of Zizia aurea is a compound umbel with bright yellow flowers. 17-Eryngium habit A beautiful and bizarre looking prairie plant is Rattlesnake Master, Eryngium yuccifolium. The leaves are parallel-veined, and resemble those of a yucca plant (a monocot). 18-Eryngium inflorescence The inflorescence of Rattlesnake Master, Eryngium yuccifolium, is a head-like cluster, which are grouped into secondary inflorescences. 19-Eryngium inflorescence l.s. In this longitudinal section of a single Eryngium yuccifolium inflorescence, you can see that the head-like structure comes from an umbel, it is just that the flowers do not have pedicels. 20-Eryngium flowers Here are individual flowers of Eryngium yuccifolium. Note the inferior ovary and the elongate styles. 21-Cicuta habit Some plants in the Apiaceae are deadly poisonous. This is the native Water Hemlock, Cicuta maculata. A small piece of the root contains enough poison to kill a person. 22-Conium habit Another poisonous species is Poison Hemlock, Conium maculatum. A drink made from the seeds and/or leaves of this plant was used to put to death the Greek philosopher Socrates.23-Heracleum habit Some members of the Apiaceae can be rather large herbaceous plants, such as this Cow Parsnip, Heracleum lanatum. Standing alongside the plant is Rick Phillippe, collections manager for plants at the Illinois Natural History Survey. 24-Heracleum leaf base Note the sheathing leaf base of Heracleum lanatum. 25-Heracleum stem Note the hollow stem of Heracleum lanatum. 26-Hydrocotyle on beach Found on beaches along the Atlantic and Gulf Coasts is Hydrocotyle bonariensis. The leaves are peltate, and the tiny flowers are pollinated by flies. 27-Foz do Iguacu The waterfalls of Foz do Iguacu in southern Brazil are a magnificant sight. They are located n