Details - Classification, evolution, and phylogeny of the families of Monocotyledons

Classification, evolution, and phylogeny of the families of Monocotyledons

Title

Classification, evolution, and phylogeny of the families of Monocotyledons

Related Titles

Series: Smithsonian contributions to botany, no. 71

By

Goldberg, Aaron

Type

Book

Material

Published material

Publication info

Washington, D.C, Smithsonian Institution Press, 1989

Notes

To some extent classification is subjective. Taxonomists differ in the relative importance they ascribe to particular characters and in the degree of difference between related taxa they deem sufficient to constitute family or ordinal rank. About 250 monocot family names have been published. Those who have attempted an overview of the system at the family level and above in the last quarter century recognize between 45 and 103 monocot families in 14 to 38 orders. I accept 57 families in 18 orders. In Table 1 I give my ordinal allocation of the families and that of 11 recent authors to indicate where there is agreement and where there are differences to be resolved. I have constructed a dendrogram to suggest relationships and degree of advancement of the orders.I have written concise, uniform descriptions of all the families of monocots emphasizing those characters that show trends between families or occur in more than one family. Each family is illustrated by analytical drawings of the flower, fruit, seed, and usually inflorescence. Several species are usually used to show the range of major variation within families and trends toward related families.Monocots and dicots have existed concurrently for most of their history, have been subjected to many of the same ecological pressures, and consequently show similar evolutionary trends. My approach to understanding evolutionary trends in characters is to relate them to the ecological factors that might be responsible for them by their selective action. The monocots probably originated under warm temperate or subtropical conditions favorable for growth. A major evolutionary trend in them has been the gradual development of characters and character states enabling them to cope with dry and hot or cold conditions and colonize generally unfavorable habitats.A second major trend has been progressively greater specialization for insect pollination. The primitive monocots have flowers with numerous