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Series 4, Volume 65, 28 Sept. 2018, No. 2 
base) with sparse glandular trichomes like those of pedicels and conspicuously or inconspicuous¬ 
ly glandular-punctate, punctations <0.1 mm in diameter, posterior lobe planar or ± conduplicate, 
oblong-lanceolate to ovate to elliptic, 23-65 mm long, longer than lateral lobes, 10-36 mm wide, 
lateral lobes lance-ovate to ovate to ovate-cordate to elliptic, 21-52 mm long, 7-27 mm wide. 
Corolla greenish white to pale yellow, 40-60 mm long, externally pubescent with erect to flexuose 
glandular (0.1-0.5 mm long) and eglandular (0.1-1 mm long) trichomes, trichomes sometimes 
very sparse, tube 25—46 mm long, narrow proximal portion 3-17 mm long, 4.5-10 mm in diame¬ 
ter near midpoint, throat 22—43 mm long, 17-23 mm in diameter at mouth, lobes spreading to 
recoiled, broadly triangular to broadly ovate to subcircular, 8-16 mm long, 6-12 mm wide, round¬ 
ed to acute and ± emarginate at apex. Stamens 2, 52-57 mm long, filaments glabrous distally, not 
seen proximally, thecae 9-15 mm long; staminodes (if present) not seen. Style 50-55 mm long, 
glabrous distally, not seen proximally, stigma subequally to unequally 2-lobed, lobes linear-oblong, 
3-5.2 mm long, 1.2-1.5 mm wide. Capsule 27-35 mm long, 6-6.5 mm in diameter, glabrous, stipe 
7-12 mm long. Seeds up to 16 per capsule, 4-6.2 mm long, 4-6 mm wide, surfaces smooth to wrin¬ 
kled. 
Phenology.— Flowering: throughout the year; fruiting: June-March. Folsom et al. 5464 
notes that corollas open in the evening; Gonzalez 7918 notes that flowers were closed at 17:00 but 
opened by 19:00. 
Distribution and habitat.— Costa Rica (Cartago, Guanacaste, Heredia, Limon, Puntarenas, 
and San Jose) and Panama (Bocas del Torro, Chiriqui, Colon, and Guna Yala), primarily (or exclu¬ 
sively?) on the Caribbean versant (Fig. 9); plants occur in and along streams in lowland to 
montane wet forests and cloud forests at elevations from 15 to 1700 m. 
Illustrations. — Figure 4A, B; Durkee (1978:232, fig. 20); Durkee (1985:14, fig. 12). 
Conservation. — Louteridium costaricense has the largest EOO (61,058 km 2 ) among con¬ 
geners. Its EOO includes at least 23 protected areas (16 in Costa Rica and seven in Panama), and 
the species has been collected in five of them. Although there are undoubtedly threats to the species 
in various portions of its extensive geographic range, considering its overall distribution and rela¬ 
tive abundance, the species is here assessed as Least Concern (LC; IUCN 2017). 
Discussion. — Corollas of Louteridium costaricense are more tubular and generally less open 
than in congeners. No significant differences were encountered between plants from Costa Rica 
and those from Panama. Considerable variation is evident in the shape and width of corolla lobes 
from oblong-lanceolate to lance-ovate and 7 to 12 mm wide (e.g., Tonduz 8123 ) to ovate-cordate 
and 21 to 32 mm wide (e.g., Herrera & Gamboa 8581). 
Additional specimens examined.— COSTARICA. Cartago: Canton de Turrialba, Valle del 
Reventazon, Grano de Oro, El Sies, Moravia de Chirripo, 09°49’50”N, 083°26’40”W, P. Campos 
& A. Campos 213 (MO); “Limon, Siquirres, Las Brisas de Pacuarito, camino a Cerro Tigre,” 
09°57’00”N, 083°25’50”W [=Cartago Province], G. Herrera 8840 (K); “Limon, Siquirres, Pacuar¬ 
ito, Las Brisas,” 09°56’10”N, 083°25’20”W [=Cartago Province], G. Herrera et al 8646 (K). 
Guanacaste: Cordillera de Tilaran, 1 km N de Las Nubes de Rio Chiquito, Zona Monteverde, 
10°22’N, 084°51’W, W. Huber & W. Zuchowski 8681 (MO); “Puntarenas,” Cordillera de Tilaran, 
Monteverde, San Gerardo Biological Station, Sendero Congo, 1 km W of Station, 10°22’N, 
084°48’W [=Guanacaste Province], D. Penneys 454 (CAS). Heredia: Finca La Selva, OTS Field 
Station on Rio Puerto Viejo just E of its jet. with Rio Sarapiqui [10°25’53”N, 084°00’13”W], 
B. Hammel & J. Trainer 13226 (CAS, DUKE, MO). Limon: Canton Siquirres, Finca de E. Berlin, 
Pocora, cuenca del Rio Destierro, [ca. 10°10’5.11”N, 083°35’41.15”W], J. Gonzalez 7918 (LSCR- 
image seen), J. Gonzalez & J. Chaves 8728 (LSCR-image seen), J. Gonzalez et al. 8157 (LSCR- 
