Bartlettina sordida, common names Blue mist flower, or Purple torch (scientific name: Bartlettina sordida) is an endemic species of Mexico and is a non-cold-resistant evergreen small shrub of the family Asteraceae. In the previous classification, it was classified in the genus Erythritis and was considered Eupatorium atrorubens. It is a plant in which Ageratum（scientific name: Ageratum houstonianum） flowers become wild, the leaves become huge, and the plant height has become over 1.5 m, though it is a different genus from Agelatum. The stem stands upright, branches and total bracts are covered with dark red short hair and look red. From summer to autumn, it makes spread the dispersal inflorescence from the tip of the stem and bloom a light purple-pink head flower. It is a nectar plant that has a fragrance on the flower butterfly. Bartlettina has many varieties, varying plant height, leaf shape and so on. It grows naturally in Mexico's tropical rainforest, and also bloomed at the Royal Botanic Garden in Sydney and drew attention.
Common name: Bartlettina Sordida, Scientific name: Bartlettina sordida, synonym: Eupatorium atrorubens, aka: Purple torch, Blue mist flower, tree height: 1.5 to 2.4 m, tree width: 1.2 m, leaf length: 25 cm , Leaf width: 20 cm, leaf shape: egg shape, leaf margin: sawtooth, leaves:opposite, inflorescence shape: discrete inflorescence, inflorescence length: 20 to 30 cm, corolla: head flower, flower color: light purple, pink, floret Diameter: 1 to 1.5 cm.