NOTESA NEW SPECIES OF COSTUS(COSTOIDEAE,ZINGIBERACEAE)FROM VERACRUZ, MEXICO Costus L. is a genus of about 90 species, witha pantropical distribution mostly in the Neotropics.The most recent taxonomic studies dealing withthe genus are those by Maas (1972, 1977) andMaas & Maas (1990). Mexico represents the northernmost distributionlimit of this genus in America. This genus is rep-resented in Mexico only by five species of subg.Costus: C. comosus (Jacquin) Roscoe var. bakeri(Schumann) Maas, C. scaber Ruiz & Pav�n, andC. pulverulentus C. B. Presl within sect. Orni-thophilus; and C. pictus D. Don, C. guanaiensisvar. tarmicus (Loesener) Maas, and C. guanaien-sis var. macrostrobilus (Schumann) Maas belongingto sect. Costus. Studies carried out during a comprehensive flo-ristic project of the Flora de la Estaci�n de BiologiaLos Tuxtlas, Veracruz, Mexico (Ibarra & Sinaca,1987), have brought to light a distinctive newspecies.Costus dirzoi Garcia-Mendoza & Ibarra-Manri-quez, sp. nov. TYPE: Mexico. Veracruz: Muni-cipio San Andr�s Tuxtla, Estaci�n de Biologia Tropical Los Tuxtlas, 18�34'-18"36'N, 95�04'-95�09'W, 200 m, 7 June 1989 (fl), Ibarra 3400 (holotype, MEXU; isotypes, BM, ENCB, K, LE, MO, U, US, XAL). Figure 1. A C. picto I). Don inflorescentia terminali in caule aphyllo (raro 1-.2 foliis), callo conspicuo, bracteola puber-ula, ovario villoso et foliis supra glabris, infra dense ve-lutinis differt. Plants 1-1.5(-2) m tall, pale green when dry, sheaths, ligules, and petioles sparsely puberulous. Sheaths (4-)4.5-7(-8) x 1-1.4(-2) cm, green; ligule (3-)4-9(-12) mm long, obliquely truncate, mostly dilacerating into fibers; petiole 3-10(-15) mm long. Leaves narrowly to broadly elliptic, (15-)20-27(-32) x 8-15 cm, (1.5-)2.1-2.5(-2.8) times longer than wide, cuneate at the base, with a (1.5-)2-3 cm acumen at the tip, upper surface glabrous, lower surface densely veluti-nous. Inflorescence ovoid to fusiform, 3-6(-10) x(2.5-)3-4 cm, elongating to 16 x 5.5 cm in fruit,borne on a leafless shoot 20-40(-70) cm tall, oroccasionally terminal on a leafy stem. Sheathsobliquely truncate, 4-5(-8) x 1.3-2 cm, minutelypuberulous, sericeous at the insertion, reddish togreen. Bracts broadly ovate, 2.5-4 x 2-3 cm,acute, coriaceous, exposed part green, glabrous,covered part reddish, puberulous; callus 5-6(-8)mm long, yellowish, rarely inconspicuous; bracteole1.5-1.8(-2) cm long, sparsely puberulous; calyx5-9 mm, sparsely puberulous, lobes deltate, (2-)3-4 mm long. Corolla 4.5-6 cm long, bright yel-low, lobes narrowly obovate, 4-5 x 1-1.8 cm,the dorsal one to 6 cm long, outer side minutelypuberulous, tube 1-2 cm long. Labellum broadlyobovate when spread out, 5-6.5 x 3-3.5 cm,yellow, margins crenulate, lateral lobes with a pu-bescent line inside, with dark red stripes, the middlelobe reflexed, irregularly 3-5 lobulate, tube 2-2.5cm; stamen narrowly elliptic, 3.3-4.5 x 1-1.2cm, yellowish white, apex dark red, rectangular,reflexed, anther 8-9(-10) mm, dorsifixed; ovary4-6(-7) mm, densely villose; style filiform; stigmabilamellate with a 2-lobed appendage and one lu-nular, ciliate structure. Capsule broadly obovoid,8-11 x 6-8 mm, densely villose, seeds 4-4.5 x2.5-3 mm, black, 5-20 per fruit. Seedlings epi-geous. Common names. Bord�n, caria agria, cana de venado. Uses. The local people chew and suck on the stems to satisfy thirst. Distribution and habitat. Costus dirzoi is known only from the Los Tuxtlas region, Veracruz, Mexico, where it grows in primary tropical rain-forest but is more abundant in gaps produced by tree falls or edges of the forest and river banks, at elevations of 160-300(-700) m. The aerial parts of the plants show growth quickly after their stems are cut. The fruits and seeds are eaten and depredated (perhaps dispersed) by mice. Flowering occurs from May to June, rarely in August, and mature fruits are found from November to Decem-ANN. MISSOURI BOT. GARD. 78: 1081-1084. 1991.
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