Inspired by the 1893 World's Fair (World's Columbian Exposition) in Chicago was the motivating factor to a group of women at the Maryland Agricultural College in 1896. They thought that Maryland should have an official state flower and they thought it should be the black-eyed Susan.
The Black-eyed Susan, (Rudbeckia hirta,) has been the official Maryland flower since 1918 when it was designated the "Floral Emblem" of Maryland by the General Assembly (Chapter 458, Acts of 1918; Code State Government Article, sec. 13-305)
In his Species Plantarum (1753), the Swedish naturalist Linnaeus described and named the flower Rudbeckia after Olav Rudbeck and his son, both professors at the University of Uppsala, and hirta from the Latin meaning "rough hairy".
Rudbeckia hirta, commonly called black-eyed Susan, is a species of flowering plant in the family Asteraceae, native to the central United States. It is one of a number of plants with the common name black-eyed Susan. Other common names for this plant include: brown-eyed Susan, brown Betty, gloriosa daisy, golden Jerusalem, Poorland daisy, yellow daisy, and yellow ox-eye daisy.
Black-eyed susan is a rough, hairy perennial daisies or coneflowers, members of the sunflower family (Asteraceae). The flower's yellow rays circle a dark-brown, spherical center measuring 2 to 3 inches in diameter. Commonly found in fields and on roadsides, they bloom between May and August, reaching 2 to 3 feet in height. They are native to the United States, east of the Rocky Mountains.
The law designating the black-eyed susan as the official Maryland state flower is found in the Maryland Statutes, Title 13, Section 13-305.
TITLE 13. STATE GOVERNMENT.
SECTION 13-305.
§ 13-305.
The black-eyed susan (Rudbeckia hirta) is the State flower.
Taxonomic Hierarchy: Black-eyed Susan
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Asteridae
Order: Asterales
Family: Asteraceae - Aster family
Genus: Rudbeckia L. - coneflower
Species: Rudbeckia hirta L. - blackeyed Susan