Evaluation of Costus Species and Their Use as Indoor Potted-Plants C. Gonçalves, C.E.F. Castro, J.A. Azevedo Filho and G.M. Dias-Tagliacozzo Instituto Agronômico, Av. Barão de Itapura, 1481 Caixa Postal 28, CEP 13001-970, Campinas, SP Brazil Keywords: Tropical plants, plant domestication, adaptability Abstract Eighteen species of Costus, nine of them naturally occurring in Brazil, were maintained during a period of 24 months. They were evaluated plant development parameters such as: a) stem and leaves characteristics (position, hairiness, brightness and distribution); b) flowering (plant age and duration); c) occurrence of pest diseases; d) adaptation to drought and shade conditions; and e) plant vigor, as an overall measure of adaptation to indoor cultivation. The species of natural occurrence in Brazil evaluated were: C. amazonicus (Loesener) Macbride, C. arabicus Linnaeu, C. comosus (Jacquin) Roscoe, C. cuspidatus N. E. Brown, C. productus Schumann, C. lanceolatus O. G. Petersen, C. lasius Loesener, C. scaber Ruiz & Pavón, C. spiralis (Jacquin) Roscoe. The other species evaluated were: C. barbatus Suesseng., C. curvibracteatus Mass, C. erythrophyllus Loes., C. laevis Ruiz & Pavón, C. malortianus Wendl., C. pictus D. Don., C. speciosus (Koening) Sm., C. spicatus (Jacq.) Sw., e C. stenophyllus Standley & J.L. Williams. The result showed that the most adapted species for indoor plant cultivation were: C. curvibracteatus, C. amazonicus, C. erythrophyllus, C. malortianus, C. cuspidatus and C. lasius. INTRODUCTION The ornamental plant market, locally and internationally, is constantly looking for the diversification of its product offerings with new or improved plant materials. Among tropical flowering plants there is a great number of species with forms, colors and exotic appeal, in addition to their excellent post production durability. Among tropical species with economic importance are the Zingiberales with its families Lowiaceae, Musaceae, Strelitziaceae, Heliconiaceae, Marantaceae, Cannaceae, Zingiberaceae and Costaceae. Costus, from the Costaceae family, has had a positive response from initial limited exports. The objectives of this work were the evaluation of eighteen species of Costus for their possible use as indoor potted-plants. MATERIAL AND METHODS Eighteen species of Costus, of which nine are naturally occurring in Brazil, were cultivated and observed for 24 months in The Agronomic Institute (Campinas/ São Paulo State/ Brazil). The plants were cultivated in a mixture of sand, soil and manure (1:1:1) in 50-liter plastic containers under 75% shade. Ten containers of each species were grown and evaluated for the following parameters (tables 1 to 4): a) Stem and leaf characteristics (position, hairiness, brightness and distribution) b) Flowering (plant age and duration) c) Occurrence of pests diseases d) Adaptation to drought and shade conditions e) Plant vigor, as an overall measure of adaptation to indoor cultivation Evaluated species of natural occurrence in Brazil were C. amazonicus (Loesener) Macbride, C. arabicus Linnaeu, C. comosus (Jacquin) Roscoe, C. igneus N. E. Brown, C. juruanus Schumann, C. lanceolatus O. G. Petersen, C. lasius Loesener, C. scaber Ruiz & Pavón, and C. spiralis (Jacquin) Roscoe. The other species evaluated were C. barbatus Suesseng., C. curvibracteatus Maas, C. erythrophyllus Loes., C. laevis Ruiz & Pavón, C. malortianus Wendl., C. pictus D. Don., C. speciosus (Koening) Sm., C. spicatus (Jacq) Sw., and C. stenophyllus Standley & J.L. Williams. Proc. Vth IS on New Flor. Crops Eds.: A.F.C. Tombolato and G.M. Dias-Tagliacozzo Acta Hort. 683, ISHS 2005 319 The evaluation criteria considered plant characteristics in addition to inflorescence and individual flower characteristics. It requires plants not be too high, and that stems and leaves also to be attractive. From the production standpoint, desirable traits are quickness to flowering, uniformity of plant response to cultural manipulations, numerous flowers per inflorescence, and long post production life. Shade resistance and drought resistance are also important considerations. RESULTS AND DISCUSSION The studied species are briefly described as following: 1) Costus erythrophyllus: Plants that grow from 0,6 to 2 meters of high, with leaves presenting an interesting characteristic in the lamina, that is green on the top side and often purplish on the other side. Its leaves, narrowly elliptic and cuneate at the base are not hairy. The inflorescence is ovoid shape, from 4 to 8 centimeters of length and from 3,5 to 6 centimeters of width. The bracts and calyxes are red while the corollas are white and the labellums are sordid-white with a yellow zone in the center and with reddish- stripped lateral lobes. This species is distributed in Brazil, Colombian Amazon, Peru and Ecuador and its occurrence in Brazil is in the Acre State. This species is used as potted plant, cut plant and also in gardens. 2) Costus curvibracteatus: Plants that grow from 1 to 3 meters of high and which leaves are narrowly obovate. It is possible that in the part below of the leaves puberulous may be found while in the part above it may be not possible this event. The inflorescence is ovoid and fusiform, from 3 to 10 centimeters of length and with 2,5 to 4,5 centimeters of width. Bracts are green in the exposed part while red in the covered part. Bracteoles are pinkish red, calyxes pinkish red or rather with green stains, corollas snow-white, labellums white and lateral lobes normally purple while the mid lobes have a large yellow zone in the center of it. This species is distributed through the Antilles, tropical regions in South America regions such as: flow of the Amazon River , south of Brazil and the Guyana and its occurrence in Brazil is in the Amapá, Bahia, Espírito Santo, Maranhão, Rondônia, Mato Grosso, Acre, Rio de Janeiro, Santa Catarina and São Paulo States The species is used as potted plant, also in gardens and potentially as a cut plant. 3) Costus amazonicus: Plants that grow from 1 to 3 meters high, which leaves do not present puberulous, and are ovoid and narrowly obovate. The inflorescence can be ovoid or cylindrical with yellow, orange-yellowish or white yellowish corollas, yellow labellums and with dark yellow stripped lateral lobes while the mid lobes have a yellow zone in the center with red margin in the center. This species is distributed in Amazonic region in Brazil, Colombia, Ecuador and Peru and its occurrence: in Brazil in the Amazon and Mato Grosso States. 4) Costus arabicus: Plants from 1 to 3 meters of high, the interior lamina of leaves are glabrous and narrowly ovate and abovate as well; the upper side is glabrous too. The inflorescence is ovoid to fusiform, acute or obtuse, from. 3 to 10 centimeters of length, of green inflorescence with white-snow flowers, green bracts in the exposed part and red in the covered part. The bracteoles are pinkish red and calyx may be pinkish red or slightly green stained. The corolla is white-snow, and lobes narrowly eliptic to narrowly obovate. The labellum is white-snow while the lateral lobes are slightly purpure; the mid lobes have a large yellow zone in the center. This species is distributed in the Antilles, tropical regions of South America, especially the Guianas, the flow of the Amazon River and South Brazil, basically in wet forests, and forested river banks, in the margins of forests and swamps. 320 In Brazil, it occurs in the States of Amapá, Bahia, Espírito Santo, Maranhão, Rondônia, Mato Grosso, Acre, Rio de Janeiro, Santa Catarina and São Paulo. 5) Costus cuspidatus: Smalls plants normally up to 0,50 meters of high. Stems normally red-purple with narrowly elliptic to obovate leaves, with inflorescence of 3 to 8 flowers, light green bracts, light green calyx, triangular lobes, orange corolla and narrowly elliptic obovate lobes. This species is distributed in Soutest from Brazil, in primary forests and deep shade and its occurrence in Brazil is in the Bahia, Espírito Santo and Rio de Janeiro States. It is world wide used in interiors due to the simple methods of cultivation. 6) Costus lasius: Thin plants of 2 meters of high, with narrowly elliptic leaves, inflorescence straight or tilted, ovoid or funned-shaped; yellow and light orange bracts, rarely with red corolla or light orange. This species is distributed in Panama, Colombia, Peru and Brazil and its occurrence in Brazil is in the Amazon region. 7) Costus comosus: Plants from 0,5 to 2 meters of high, wiht the possibility to reach up to 3 meters. The leaves are narrowly elliptic to obovate. The inflorescence is ovoid and cylindrical with 6 or 10 centimeters of length. The bracts are from green to reddish to green again, while the bracteoles and calyx are of reddish color. The corolla and the labellum are yellow. This species is distributed in Central America and Venezuela. 8) Costus productus: Small plants, from 0,3 to 1,5 meters high, the leaves are narrowly elliptic, or obovate rounded shape in the base. The inflorescence is ovoid wiht 6 to 11 centimeters of length. The bracts are red and bright orange. The corolla are light yellow or orange. This species is distributed in the Amazon region from Brazil, Colombia and Peru. and its occurrence in Brazil is in the Acre State. 9) Costus scaber: Thin plants that grow from 0,5 to 3 meters high, and whose leaves are narrowlly elliptic. The inflorescence is ovoid and narrowly cilincric, wiht 4 to 10 centimeters of lenght. The bracts are red-orange to red. The bracteole and calyx are reddish. The corollas are from orange to yellow. The lobes are narrowly obovate and the labellum is yellow. Also the lateral lobes are spiral. This species are wildly spread through the Antilles, Central America and Mexico. In Brazil, it occurs in the States of: Acre, Amazon, Pará, Bahia, Espírito Santo, Pernambuco and Santa Catarina.