Rudbeckia laciniata is a species of flowering plant in the sunflower/daisy family Asteraceae, native to eastern North America, most often found in flood plains and moist soils.
Rudbeckia californica is a species of flowering plant in the Sunflower or Aster Family (Asteraceae), known by the common name California coneflower.
Rudbeckia hirta, commonly called black-eyed-Susan, is a North American flowering plant in the sunflower family, native to Eastern and Central North America and naturalized in the Western part of the continent as well as in China.
 It has now been found in all 10 Canadian Provinces and all 48 of the states in the contiguous United States.
Rudbeckia maxima, the great coneflower, is a flowering plant in the Asteraceae family, which is used like an ornamental plant.
 They can reach a maximum height of eight feet.
 Once it produces seeds, finches and other small birds come to feed on them.
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle.
 In the first year, the plant grows leaves, stems, and roots (vegetative structures), then it enters a period of dormancy over the colder months.
 Usually the stem remains very short and the leaves are low to the ground, forming a rosette.
 Many biennials require a cold treatment, or vernalization, before they will flower.
 During the next spring or summer, the stem of the biennial plant elongates greatly, or "bolts".
 This typically makes biennial vegetables such as spinach, fennel and lettuce unusable as food.
 The plant then flowers, producing fruits and seeds before it finally dies.
 There are far fewer biennials than either perennial plants or annual plants.
Rudbeckia fulgida, the orange coneflower or perennial coneflower, is a species of flowering plant in the family Asteraceae, native to eastern North America.
Petunia is genus of 35 species of flowering plants of South American origin, closely related to tobacco, cape gooseberries, tomatoes, deadly nightshades, potatoes and chili peppers in the same family, Solanaceae.
 The popular flower of the same name derived its epithet from the French, which took the word "petun", meaning "tobacco," from a Tupi–Guarani language.
 An annual, most of the varieties seen in gardens are hybrids ("P." × "atkinsiana", also known as "P." × "hybrida").
Rudbeckia is a plant genus in the sunflower family.
 The species are commonly called coneflowers and black-eyed-susans; all are native to North America and many species are cultivated in gardens for their showy yellow or gold flower heads.
Quinoa ( or , from Quechua "kinwa " or "kinuwa ") is the common name for Chenopodium quinoa, a flowering plant in the amaranth family Amaranthaceae.
 It is a herbaceous annual plant grown as a grain crop primarily for its edible seeds. Because it is not a grass, it is a pseudocereal rather than a true cereal.
 Quinoa is closely related to the edible plants beetroot, spinach, and amaranth ("Amaranthus spp.")
, another pseudocereal which it closely resembles.
Rudbeckia occidentalis is a species of flowering plant in the aster family known by the common name western coneflower.
 It is native to the northwestern United States from Washington to northern California and east to Wyoming and Montana, where it grows in moist habitat types, such as meadows.
 It is an erect perennial herb growing from a thick rhizome, its mostly unbranched stem approaching two meters in maximum height.
 The large leaves are generally oval but pointed, and lightly to deeply toothed along the edges, growing to 30 centimeters long.
 The inflorescence is one or more flower heads with purplish bases up to 6 centimeters wide.
 There are no ray florets, just an array of reflexed phyllaries around the purple-brown center packed with disc florets.
 This center, containing the receptacles, lengthens to several centimeters in length as the fruits develop.
 The fruits are achenes each a few millimeters long, some tipped with pappi of tiny scales.

Question: Which flowering plant is related to edible vegetables, Petunias or Rudbeckia?
Answer: Petunia