Louteridium costaricense Radlk. & Donn. Sm., Bot. Gaz. (Crawfordsville)

Daniel, Thomas F. & Tripp, Erin A., 2018, Louteridium (Acanthaceae: Acanthoideae: Ruellieae: Trichantherinae): Taxonomy, Phylogeny, Reproductive Biology, and Conservation, Proceedings of the California Academy of Sciences 65 (2), pp. 41-106 : 75-76

3. Louteridium costaricense Radlk. & Donn. Sm., Bot. Gaz. (Crawfordsville) 37:422. 1904. TYPE.— COSTA RICA. Cartago: Tucurrique, Las Vueltas [ca. 09°50’53.61”N, 083°43’35.82”W], 1000 m, III-1899 (flr), A. Tonduz 8123 (holotype: US!) .

Perennial herbs to shrubs to 2 m tall, terrestrial. Older (woody) stems subquadrate, lenticellate, lacking trichomes; younger (herbaceous) stems subquadrate to flattened, glabrous. Leaves not all seasonally deciduous, ± evenly distributed along stems, petiolate, petioles to 85 mm long, blades subsucculent, (ovate-elliptic to) elliptic to obovate, 125–335 mm long, 43–153 mm wide, 2.2–3.2 × longer than wide, acute to acuminate to acuminate-falcate at apex, attenuate at base, surfaces glabrous, margin entire to sinuate. Inflorescence a terminal pedunculate (racemose thyrse to) thyrse to 335 mm long (including peduncle and excluding corollas), peduncle to 230 mm long, glabrous, rachis glabrous; dichasia often modified via sympodial expansion and appearing like lateral branches, opposite or alternate, (subsessile to) pedunculate, 1–many-flowered, to 117 mm long (excluding corollas), dichasial peduncles 1–15 mm long, glabrous. Bracts persistent, lance-ovate to ovate to elliptic (or subfoliose proximally), 6–70 mm long, 2–24 mm wide, abaxially glabrous or glandular punctate (but lacking elongate trichomes), sometimes with lenticel-like encrustations as well. Bracteoles persistent, ovate to elliptic, 3. 5–11 mm long, 2–6. 5 mm wide, abaxial surface like that of bracts, those of a pair sometimes basally fused for ca. 1 mm (at least along one side). Flowers pedicellate, pedicels 6–58 mm long, glabrous or sometimes covered with crystal-like punctations or globules or pubescent with stipitate glandular trichomes (sometimes sparse) 0.1– 0.2 mm long. Calyx pale green to white, 23–65 mm long, lobes subheteromorphic to heteromorphic, membranaceous, acute to subacuminate at apex, abaxially glabrous or pubescent (at least near base) with sparse glandular trichomes like those of pedicels and conspicuously or inconspicuously 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 diameter 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 wrinkled.

PHENOLOGY.— Flowering: throughout the year; fruiting: June–March. Folsom et al. 5464 notes that corollas open in the evening; González 7918 notes that flowers were closed at 17:00 but opened by 19:00.

DISTRIBUTION AND HABITAT.— Costa Rica (Cartago, Guanacaste, Heredia, Limón, Puntarenas, and San José) and Panama (Bocas del Torro, Chiriquí, Colón, and Guna Yala), primarily (or exclusively?) 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 congeners. 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 relative 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.— COSTA RICA. Cartago: Cantón de Turrialba, Valle del Reventazón, Grano de Oro, El Sies , Moravia de Chirripó , 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, Pacuarito, Las Brisas,” 09°56’10”N, 083°25’20”W [= Cartago Province], G . Herrera et al. 8646 ( K) . Guanacaste: Cordillera de Tilarán, 1 km N de Las Nubes de Río Chiquito, Zona Monteverde , 10°22’N, 084°51’W, W . Huber & W . Zuchowski 8681 ( MO); “ Puntarenas,” Cordillera de Tilarán, 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 Río Puerto Viejo just E of its jct. with Río Sarapiquí [10°25’53”N, 084°00’13”W], B . Hammel & J . Trainer 13226 ( CAS, DUKE, MO) . Limón: Cantón Siquirres, Finca de E . Berlin, Pocora, cuenca del Río Destierro , [ca. 10°10’5.11”N, 083°35’41.15”W], J . González 7918 (LSCRimage seen), J . González & J . Chaves 8728 (LSCR-image seen), J . González et al. 8157 (LSCRimage seen); Cantón Siquirres, La Alegría , Alto Botella , [ca. 10°05’45.64”N, 083°36’58.36”W], J . González et al. 7967 (LSCR-image seen), 9618 (LSCR-image seen); Cantón Siquirres, Florida , Alto Botella , [10°05’19.97”N, 083°33’26.45”W], J . González et al. 9353 (LSCR-image seen); Cantón Siquirres , Pocora , Cuenca del Río Destierro, Cordillera de Talamanca, Cantón de Matina , 200 m aguas abaja de la confluencia de Quebrada Cañabral con Río Barbilla , 10°00’10”N, 083°25’30”W, G . Herrera 2286 ( DUKE, MO); Almirante, Cerro Chiqui , 09°43’40”N, 083°18’30”W, G . Herrera & W . Gamboa E . 8581 ( F, K, MEXU, MO, NY, US) ; 10 km SW of Siquirres on road to Turrialba, E of ridge top, J. MacDougal 1110 ( DUKE); Cantón de Limón, Cordillera de Talamanca , Cerro Muchilla , Fila Matama , entrando por pueblo El Progresso , 09°47’40”N, 083°06’30”W, R . Robles & A . Chacón 2765 ( MO). Puntarenas: vicinity of Finca Las Cruces , SE of San Vito on road to Via Neilly , [ca. 08°47’14.82”N, 082°57’25.04”W], R . Weaver et al. 1777 ( DUKE). San José : from La Montura to Los Chorritos, L . Gomez et al. 20929 ( MO) . PANAMA. Bocas del Torro: Fish Creek Mts. , vicinity of Chiriqui Lagoon [ca. 08°58’59.68”N, 082°13’48.70”W], H . von Wedel 2283 ( MO) . Chiriquí: Fortuna Dam site [ca. 08°44’46.90”N, 082°14’38.50”W], J . Folsom & R . Dressler 5464 ( MO); La Fortuna hydroelectric project, ridge behind camp, [08°41’25.09”N, 082°13’47.82”W], B . Hammel 2228 ( MEXU, MO) . Colón: along Río Guanche , 3–7 km above bridge [ca. 09°29’N, 079°38’W], B . Hammel et al. 4916 ( MO); ca. 2– 3 mi up Río Guanche [ca. 09°30’30”N, 079°39’30”W], H . Kennedy & R . Foster 2180 ( MO) . Guna Yala (San Blas): Nusagandi, El Llano–Cartí Road , along creek on Atlantic slope [ca. 09°18’18.56”N, 078°59’20.14”W], G . de Nevers & B . González 3656 ( DUKE, MEXU, MO); El Llano–Cartí Road , KM 19 . 1 [ca. 09°20’51.93”N, 079°01’54.94”W], G . de Nevers et al. 6195 ( CAS, DUKE, MEXU, MO); trail to Cerro Obu ( Habu of maps) from Río Urgandi ( Río Sidra ) [ca. 09°23’59.51”N, 078°49’40.88”W], G . de Nevers et al. 8007 ( CAS, MO); El Llano–Cartí hwy., ca. 23 km N of El Llano, R . Dressler 4310 ( DUKE, ENCB, F, MO); Nusagandi, El Llano–Cartí road, 09°19’N, 078°55’W, H. van der Werff 7019 ( CAS, MO) .

Figures

FIGURE 9. Map of Costa Rica (with provinces) and Panama (with provinces and comarcas) with distribution of Louterid- ium costaricense. Dots may pertain to multiple collections.