Aristolochia gorgona (Aristolochiaceae), a new species with giant ¯owers from Costa Rica and Panama MARIO A. BLANCO1 Blanco, M. A. (Instituto Centroamericano de InvestigacioÂn BioloÂgica y Con- servacioÂn, P.O. Box 2398-250, San Pedro de Montes de Oca, San JoseÂ, Costa Rica; and JardõÂn BotaÂnico Lankester, Universidad de Costa Rica, 1000 San JoseÂ, Costa Rica). Aristolochia gorgona (Aristolochiaceae), a new species with giant ¯owers from Costa Rica and Panama. Brittonia 54: 30±39. 2002.ÐAristolochia gorgona is described from the Atlantic watershed of Costa Rica and central and eastern Panama. It is similar to A. grandi¯ora Sw., with which it has been con- fused in the past. The extensive reported synonymy of A. grandi¯ora is reviewed and compared with the new entity. Some new terms are proposed for better de- scribing ¯oral structure in this species complex, and suggestions are made for its collection and study. Aristolochia gorgona is one of the largest-¯owered plant species (in terms of perianth area) in the Neotropics. Key words: Aristolochia, Aristolochiaceae, collecting techniques, Costa Rica, ¯ower structure, Panama. Blanco, M. A. (Instituto Centroamericano de InvestigacioÂn BioloÂgica y Con- servacioÂn, P.O. Box 2398-250, San Pedro de Montes de Oca, San JoseÂ, Costa Rica; y JardõÂn BotaÂnico Lankester, Universidad de Costa Rica, 1000 San JoseÂ, Costa Rica). Aristolochia gorgona (Aristolochiaceae), a new species with giant ¯owers from Costa Rica and Panama. Brittonia 54: 30±39. 2002.ÐAristolochia gorgona se describe de la vertiente AtlaÂntica de Costa Rica y del centro y este de PanamaÂ. Es similar a A. grandi¯ora Sw., con la cual se ha confundido en el pasado. La extensa sinonimia reportada para A. grandi¯ora es revisada, y com- parada con la nueva entidad. Se proponen algunos teÂrminos nuevos para describir mejor la estructura ¯oral en eÂste complejo de especies, y se ofrecen sugerencias para su recoleccioÂn y estudio. Aristolochia gorgona es una de las especies ve- getales con ¯ores maÂs grandes (en cuanto al aÂrea del perianto) en el NeotroÂpico. Aristolochia grandi¯ora was described by caped from cultivation. It is considered the Swartz (1788), based on a specimen from largest-¯owered plant in the Neotropics Jamaica. As presently conceived by most (Standley & Steyermark, 1946; Barringer, taxonomists, the species is common but var- 1983a). Similar large-¯owered aristolochias iable in ¯ower size and shape, ranging from have been described (see synoymy in Gon- southern Mexico to Ecuador and the West zaÂlez, 1990), but all are considered conspe- Indies. It has become naturalized in Java ci®c with A. grandi¯ora by recent monog- (Cammerloher, 1923), Sri Lanka (Petch, raphers (e.g., GonzaÂlez, 1990, 1994). A 1924), and Florida (Wunderlin, 1998), es- striking new species with giant ¯owers, closely related to A. grandi¯ora, is here de- 1 Current mailing address: University of Florida, De- scribed as new. Its ¯owers are distinctive in partment of Botany, 220 Bartram Hall, P.O. Box living specimens, but herbarium specimens 118526, Gainesville, Florida 32611-8526 U.S.A. have been confused with the latter species. Brittonia, 54(1), 2002, pp. 30-39. ISSUED: 29 May 2002 q 2002, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A. 2002] BLANCO: ARISTOLOCHIACEAE 31 In the following description and discus- popodium and prophyll not atrophied in sion, the terminology for ¯oral parts fol- branches (pseudostipules absent). Leaves lows Pfeifer (1966) and GonzaÂlez (1990, alternate, distichous, simple; petiole 2.5±10 1994). Due to the higher structural com- cm long; blade triangular-cordate, 5±27 cm plexity of the calyx in this and related spe- long (from tip of basal lobes to apex), 5± cies (compared to other aristolochias), how- 21 cm wide, cordate basally with a wide- ever, the following terms are newly coined open sinus 2±6 cm deep, and then attenu- or modi®ed from Cammerloher (1923) to ated into petiole, entire along margin, acute simplify description. These terms might to acuminate apically, glabrous adaxially, also prove useful in future pollination stud- glabrous to hispidulous abaxially; venation ies. The ``vestibule'' refers to the chamber palactinodromous with 3 main veins di- formed by the distalmost part of the tube. verging from the base, the main lateral Cammerloher's Hintergrund, or ``back- veins curving into the basal lobes, with 4± ground,'' refers to the internal wall of the 5 main branches each; tertiary veins more vestibule. The ``gullet'' (Cammerloher's or less perpendicular to the primaries and ``Reuse'') refers to the curved, proximal secondaries; veins impressed adaxially, part of the tube, in between the vestibule prominent abaxially. In¯orescences axil- and the syrinx. These two parts of the tube lary from young stems, single-¯owered, are separated by a short, narrow passage pendent; peduncle 6±10 cm long, bracteo- (the ``bottleneck''), and differ in internal late, green; bracteole suborbicular, perfoli- texture, indument, and coloration, even ate, with an acute apex, to 2 cm wide, when they are similar in appearance exter- green. Pedicel plus ovary to 8 cm long, nally. The ``nectary'' refers to a wide, glan- straight, ribbed, reddish. Flower with a dular zone located proximally on the dorsal, strong putrid smell. Calyx complexly three- internal surface of the utricle (described for dimensional in structure; utricle pyriform, A. grandi¯ora by Cammerloher, 1923); the gibbous, 14±19 3 5.5±10 cm, with 6 prom- utricle wall is thicker in the zone of the nec- inent external ribs, cream-colored with pur- tary. In A. gorgona, the limb folds in such plish ribs and reticulated venation external- a way that it presents two faces: a ``frontal ly, white with cottony hairs and a some face'' and a ``lower face'' (see Fig. 1D and bare, purple spots near the base internally. E, respectively). Nectary oval, 3.2 3 1.4 cm, orange-brown with a purple band distally. Syrinx cylin- Aristolochia gorgona M. A. Blanco, sp. drical, to 3.5 cm long, 1.4±1.7 cm diam. at nov. (Fig. 1) the opening, directed obliquely into the utri- cle, cream with a purple rim. Tube sigmoid, TYPE: COSTA RICA. Heredia: Puerto divided into a ``gullet'' and a ``vestibule,'' Viejo de SarapiquõÂ, EstacioÂn BioloÂgica La 12.5 cm long, same color as utricle exter- Selva, Quebrada SuraÂ, near the Laboratory, nally. Gullet U-shaped, 7.5 cm long, 2.8 cm 108269N, 838599W, 50 m, 4 Jan 2001 (¯, wide at the bottom; white internally. Bot- bud), M. Blanco 1752 (HOLOTYPE: USJ, in- tleneck 2 mm wide (in longitudinal section) cluding material in spirit; ISOTYPES: CR, in one measured ®rst-day ¯ower. Vestibule MO, NY). a wide, gibbous, more or less transversely bilobed chamber, 5 cm long, 7.5 cm wide, Aristolochiae grandi¯orae Sw. af®nis, sed ¯oribus 2.8 cm deep at the middle; internal wall majoribus, limbus calyce plicatus frontalis atque infra cream-colored, heavily blotched with trans- tubus calyce, projecturae parvulae vermiformis interius obtecta, cauda minore. verse dark maroon bands that become solid in the distal third, covered by downward- Herbaceous vine, becoming semi- pointing cream hairs. Annulus thin, sharp- woody toward base with age, but never tru- edged, to 1.5 cm high, dark orange-brown, ly woody; peridermis not corky; stem and opening (fauces) 6.4 cm high (longitudinal- leaves aromatic. Stem twining, ribbed, 3±4 ly), facing obliquely downward. Limb mm diam. when young, reaching 1.5 cm abruptly expanding from the annulus, mas- diam. at the base of the plant, glabrous; hy- sive, the distal half folding under the tube, 32BRITTONIA [VOL. 54 FIG.1. Aristolochia gorgona (Blanco 1752, USJ). A. Stem and leaves. B±F. Flower (drawn from photographs of fresh ¯owers). B. Side view. C. Oblique view from back. D. Front view. E. View from below; front of ¯ower toward the top. F. Longitudinal section. G. Detail of limb margin and tentacles. H, I. Gynostemium. H. Lateral view. I. Top view. 2002] BLANCO: ARISTOLOCHIACEAE 33 thus presenting two faces, cordiform with form a corky bark, contrary to the asser- two wide upper lobes, 25±31 cm long, 25± tions of Barringer (1983a) and Cook 30 cm wide when held ¯at, marginally (2001). Some branches produced low in the fringed, the fringes ¯attened, cirrhose, 3±10 main stem grow toward the ground and be- mm long; apically obtuse with a terminal come runners that produce adventitious cauda (appendix) 5 cm long, 2 mm wide; roots at each node. These resume the climb- cream suffused with purple externally, the ing mode many meters away from the base internal surface cream with clear orange- of the plant, establishing new clumps by brown blotches (almost solid in some ¯ow- vegetative reproduction. ers), darker brown around the opening, vel- Flowering occurs throughout the year. vety in texture, the whole surface densely Flowers are normally produced 3±15 m covered by small vermiform projections from the ground. Numerous muscid and (tentacles), these cylindrical, minutely pa- phorid ¯ies (as well as staphylinid beetles) pillose, clear orange-brown with a dark have been found trapped inside the utricles brown apex, 5±20 mm long, 1±2 mm thick of ®rst-day ¯owers. Similar ¯ies were (0.5±1 mm thick and totally black when found by both Cammerloher (1923) and dry). Frontal limb face directed obliquely Hilje (1984) in Aristolochia grandi¯ora, upward with re¯exed sides, 15±22 cm long, suggesting that there is a potential for hy- 15±18 cm wide (when sides re¯exed); low- bridization if both species occurred togeth- er limb face almost horizontal, with sides er. However, available herbarium specimens and apex re¯exed, 24 cm long, 13 cm wide do not indicate sympatry (in Costa Rica, A.