Cosmos pacificus is a Mexican species of plants in the sunflower family.
 It is native to southwestern and west-central Mexico from Sinaloa to Chiapas.
Chasmanthium is a genus of North American plants in the grass family.
Cosmos longipetiolatus is a Mexican species of plants in the sunflower family.
 It has been found only in the state of Jalisco in southern Mexico.
Cosmos ochroleucoflorus is a Mexican species of plants in the sunflower family.
 It has been found only in the state of Durango in northwestern Mexico.
Cosmos sherffii is a Mexican species of plants in the sunflower family.
 It has been found only in the state of Oaxaca in southern Mexico.
Thelesperma is a genus of North American and South American plants in the cosmos tribe within the sunflower family.
 Greenthread is a common name for plants in this genus.
Helianthus petiolaris is a North American plant species in the sunflower family, commonly known as the prairie sunflower or lesser sunflower.
 Naturalist and botanist Thomas Nuttall was the first to describe the prairie sunflower in 1821.
 The word "petiolaris" in Latin means, “having a petiole”.
 The originated in western United States, but has since expanded east.
 The prairie sunflower is considered a be a weed.
Cosmos parviflorus is a North American species of plants in the sunflower family.
 Common names include southwestern cosmos in the US and juve or aceitilla blanca in Mexico.
 In many places it is a common weed in agricultural fields, although it also grows in grassy meadows in forested areas.
 The species appears to be native in Texas, New Mexico, Colorado, Arizona, and Utah.
 Collections have also been made from Massachusetts, Maine, Maryland, Missouri, Rhode Island, although it appears to be introduced to those regions.
 It is widespread in Mexico from Chihuahua to Oaxaca.
Scorzonera hispanica, black salsify or Spanish salsify, also known as black oyster plant, serpent root, viper's herb, viper's grass or simply scorzonera, is a perennial member of the genus "Scorzonera" in the sunflower family (Asteraceae), cultivated as a root vegetable in the same way as purple salsify ("Tragopogon porrifolius"), also in the sunflower family.
Cosmos is a genus, with the same common name of cosmos, consisting of flowering plants in the sunflower family.

Question: Are the genus Chasmanthium and Cosmos both members of the sunflower family
Answer: no