Costus curvibracteatus is a tropical rhizomatous perennial native to Costa Rica and Panama.
 A member of the spiral ginger family of plants, its common name is orange tulip ginger.
 It is also sometimes referred to as spiral ginger; however, this common name is better associated with "Costus barbatus", a more widely cultivated and very similar species.
 Despite the name and its relation to the ginger family (Zingiberaceae), the rhizomes of the orange tulip ginger are not edible.
Costaceae, or the "Costus" family, is a family of pantropical monocots.
 It belongs to the order Zingiberales, which contains horticulturally and economically important plants such as the banana (Musaceae), bird-of-paradise (Strelitziaceae), and edible ginger (Zingiberaceae).
 The seven genera in Costaceae together contain about 143 known species (1 in "Monocostus", 2 in "Dimerocostus", 16 in "Tapeinochilos", 2 in "Paracostus", c. 8 in "Chamaecostus", c. 5 in "Hellenia", and c. 80 in "Costus").
 They are native to tropical climates of Asia, Africa, Central America, and South America.
 Several species are frequently found in cultivation.
Costus osae is a rare member of the Costus family.
 One of many rare tropical plants in the Costus family, "Costus osae" is a species native to Costa Rica described in 1997 .
 It has also been reported from Colombia.
Paulus Johannes Maria "Paul" Maas (born 27 February 1939, in Arnhem) is a botanist from the Netherlands and a specialist in the flora of the neotropics.
 Maas has identified and named about two hundred fifty plants from the Burmanniaceae, the Costus Family (Costaceae), the Gentian Family (Gentianaceae), the Bloodwort Family (Haemodoraceae), the Banana Family (Musaceae), the Olacaceae, the Triuridaceae, and the Ginger Family (Zingiberaceae).
Arctotheca is a small genus of flowering plants in the aster family.
 They are annuals or perennials native to southern Africa.
 At least two species are widely naturalized elsewhere, including Europe, California, Argentina, and Australia.
Costus is a group of perennial herbaceous plants in the family (Costaceae) described by Linnaeus as a genus in 1753.
 It was formerly known as "Hellenia" after the Finish botanist Carl Niclas von Hellens.
 It is widespread through tropical and subtropical regions of Asia, Africa, and the Americas.

Question: Are Costus and Arctotheca both plants?
Answer: yes