Louteridium mexicanum (Baill.) Standl., Contr. U.S. Natl. Herb.

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 : 88-91

7. Louteridium mexicanum (Baill.) Standl., Contr. U.S. Natl. Herb. 23:1338. 1926. Neolindenia mexicana Baill., Bull. Mens. Soc. Linn. Paris 2:851. 1890. TYPE.— MEXICO. Veracruz or Chiapas: “forêts humides de Zacualpan, Chiapas,” II-1840 (flr), J . Linden s.n. (holotype: P!; isotypes: G!, K!). A collection number (1637) that is not on specimens at P and G, is on the specimen from Hooker’s herbarium at K .

Louteridium conzattii Standl., Contr. U.S. Natl. Herb. 23:1338. 1926. TYPE.— MEXICO. Oaxaca: Distr. Tuxtepec, de Jalapa a La Raya, margen izquierda del Río Grande , [ca. 18°01’16.00”N, 096°34’25.98”W], 450 m, 3-XI-1919 (buds), C. Conzatti 3788 (holotype: US-1014038!; isotypes: MEXU! US-1014039!).

Shrubs to trees to 12 m tall, terrestrial. Older (woody) stems subquadrate, irregularly striate-fissured, glabrous or glabrate; younger (herbaceous) stems quadrate to quadrate-sulcate, internodes glabrous or with sparse flexuose to antrorse eglandular trichomes to 0.5 mm long, nodes glabrous or with some flexuose eglandular trichomes to 0.5 mm long. Leaves not all seasonally deciduous, evenly distributed on new growth, petiolate, petioles to 220 mm long, blades membranaceous, broadly ovate to ovate to ovate-elliptic to elliptic to broadly elliptic, 40–360 mm long, 21–170 mm wide, 1.3–2.9 × longer than wide, acuminate to acute-apiculate to caudate at apex, acute to round- ed to subcordate at base, adaxial surface glabrous, abaxial surface glabrous or pubescent along major veins with trichomes like those at nodes, margin ± entire to crenate. Inflorescence a terminal pedunculate (racemose thyrse to) thyrse to 390 mm long (including peduncle and excluding corollas), peduncle to 190 mm long, glabrous or pubescent like young stems, rachis glabrous or pubescent with flexuose to flexuose-antrorse eglandular trichomes 0.2–0.8 (–1) mm long (villous), trichomes sometimes restricted to nodes; dichasia modified by sympodial expansion into contract- ed to ± expanded unbranched or branched short-shoots to 25 (–46) mm long, opposite, subsessile to pedunculate, 3–many-flowered, to 120 mm long (excluding corollas), dichasial peduncles 1–22 mm long, glabrous or villous. Bracts often caducous, sessile to petiolate, ovate to lance-elliptic to linear, 20–48 mm long, 2–16 mm wide (or the proximalmost pair sometimes foliose and larger), abaxially glabrous or pubescent with antrorsely appressed eglandular trichomes. Bracteoles and secondary bracteoles usually persistent, lance-ovate to lanceolate to linear-lanceolate, 10–25 mm long, 1–8 mm wide, abaxially glabrous or pubescent with a few antrorsely appressed eglandular trichomes to 0.5 mm long along midvein or pubescent with latter type trichomes over entire surface. Flowers pedicellate, pedicels to 85 mm long, glabrous or villous. Calyx 17–39 mm long, lobes appearing distinct or fused at base for 1–2 mm, heteromorphic, ± membranaceous, abaxially appearing glabrous although covered with minute sessile glands (glandular punctate; punctations <0.05 mm in diameter) and posterior lobe sometimes sparsely villous along keel, posterior lobe conduplicate, ovate, 16–36 mm long, ± equaling to slightly longer than lateral lobes, 9–14 mm wide, acute to attenuate to subfalcate at apex, lateral lobes lunate, 16–32 mm long, 6–12 mm wide, rounded to acute to subacuminate at apex. Corolla usually greenish and maroon (also described as white with purplish lobes and pale rose in plants from San Felipe Usila, Oaxaca; see discussion below), 38–54 mm long, externally puberulent with sessile to subsessile glands 0.05– 0.1 mm long and often with glandular and eglandular trichomes to 0.2 mm long as well, tube (19–) 30–35 (–42) mm long, narrow proximal portion 8–14 mm long, 5–10 mm in diameter near midpoint, throat 15–23 mm long, 24–33 mm in diameter at mouth, lobes recoiled, subtriangular to broadly ovate to elliptic, 10–16 mm long, 8–14 mm wide, rounded at apex. Stamens 2, 60–77 mm long, filaments glabrous distally, pubescent proximally with eglandular trichomes, thecae 9–13 mm long; staminodes 2, 1–3 mm long. Style 72–85 mm long, glabrous (or sometimes with sessile to subsessile glands to 0.05 mm long near base), stigma subequally to unequally 2-lobed, lobes linear-elliptic to elliptic to obovate-elliptic, 1–3. 8 mm long, 0.6– 1.5 mm wide. Capsule 16–24 mm long, 4–8 mm in diameter, sparsely puberulent with sessile to subsessile glands to 0.05 mm long, stipe 1–2 mm long. Seeds up to 16 per capsule, 4–5. 5 mm long, 3.5– 5 mm wide, surfaces smooth or covered with subconic papillae.

PHENOLOGY.— Flowering: September–May; fruiting January–May. Based on greenhouse observations of Breedlove & Daniel 70879gh, corollas open after 17:00 and all fall by 11:00 the next morning.

DISTRIBUTION AND HABITAT.— Southern Mexico (Chiapas, Oaxaca, Puebla, Tabasco, Veracruz) and Guatemala (Alta Verapaz, Petén) ( Fig. 11 ); plants occur on slopes and along watercourses on limestone (often karstic) in primary or secondary lowland rain forests (selva alta perennifolia), montane rain forests, cloud forests, and evergreen seasonal forests (including selva mediana subperennifolia) at elevations from 50 to 1200 m. The distribution of this species appears to be entirely on the versants of the Gulf of Mexico and the Caribbean Sea. Daniel et al. (2012) report- ed this species from Guatemala. Plants from Guatemala previously attributed to L. mexicanum pertain to L. purpusii (see discussion in Daniel 1995).

LOCAL NAMES.— “K’o’och batz’” (Paniagua 539); “oj-oj” (Kunkel 161); “palo aguañoso” (Ramos & Martínez S. 620); “sabal tzununte” (Palacios E. 9631); “Uc’o’och chuba’atsir wis” (Levy T. & Durán F. 398).

USES.— Leaves applied against the body for fever (Wendt et al. 3614); a drink made from the boiled leaves is used for “dolor orinar” (Paniagua 539).

ILLUSTRATIONS.— Figures 4E, 15.

CONSERVATION.— Louteridium mexicanum is the most commonly collected species in Mexico, and has an EOO of 35,531 km 2. At least nine protected areas are located entirely or partially within its EOO, and the species has been collected in two of them. Frequency data from herbarium collection labels varies from scarce to infrequent to common to abundant. Although unidentified threats are undoubtedly present in portions of its geographic distribution, a preliminary conservation assessment of Least Concern (LC) is proposed for this species.

DISCUSSION.— Daniel (1995) discussed the probable state from which the type was collected; this would appear to be Veracruz rather than Chiapas. Linden collected in both states ( Ossenbach 2009), but no “Zacualpan” has been located in Chiapas (D. Breedlove, personal communication in 1994). Zacualpan (or Zacuapan or Zacuapam [ca. 19°12’46.44”N, 096°51’8.73”W], see Sousa S. 1969; not the town of Zacualpan at 20°26’1.71”N, 098°20’57.69”W in northwestern Veracruz), Carl Sartorius’ large hacienda located between Jalapa and Córdoba in west-central Veracruz, with its headquarters at El Mirador, is known to have been visited by several early Mexican collectors, including Linden ( Ossenbach 2009). Because it is ca. 42 km north of the currently known distributional range of L. mexicanum ( Fig. 11 ), and because of the ambiguity of the locality based on Linden’s indication of Chiapas on the collection labels, Zacuapam (shown in Fig. 11 with a question mark) is not included in the calculation of the EOO for the species.

Based on living flowers of Breedlove & Daniel 70879cv, the coloration of corollas of this species can be more fully described as follows: the narrow proximal portion of the tube (covered by the calyx) is green; the throat is green with maroon veins and tinged with maroon between the major veins; the lips (with recoiled lobes) are mostly maroon.

Daniel (1995) noted considerable variation in pubescence, leaf shape, bract persistence, and bract shape among specimens from Chiapas, Mexico. One of the two collections (Breedlove 24803, Palacios E. 385) that he indicated showed some intermediacy with L. donnell-smithii in pubescence was sampled in the phylogenetic analysis. Palacios E. 385 was strongly supported as nested within the clade of other sampled plants of L. mexicanum ( Fig. 1 ). Thus, both plants are here included within L. mexicanum .

Somewhat atypical plants from the vicinity of San Felipe Usila, Oaxaca (e.g., Ibarra M. et al. 3758, 3765; Calzada et al. 16579) are distinctive by their long calyces (30–39 mm) with the posterior lobe conspicuously attenuate-falcate apically, corollas pale rose to white with purplish lobes and pubescent with glandular and eglandular trichomes to 0.2 mm long, and rachis (i.e., Calzada et al. 16579) often somewhat scurfy to minutely puberulent with sessile to subsessile glandular trichomes less than 0.05 mm long. In Calzada et al. 16579, the calyx and pedicels are like more typical specimens of L. mexicanum , and the rachis often has longer eglandular trichomes to 0.1 mm as well. Although similar calyces and trichomes on corollas are sometimes seen elsewhere among specimens of L. mexicanum , the corolla color of these collections appears to be unusual compared to other Mexican representatives of the species. However, corollas of Foerther et al. 10940 from Guatemala are described as brownish violet. In pubescence of the rachis, these plants somewhat resemble L. purpusii . On the whole, they appear more like L. mexicanum , in which species they are treated here.

ADDITIONAL SPECIMENS EXAMINED.— MEXICO. Chiapas: Mpio. Ocosingo, 4.4 km SO de San Javier , 16°48’49”N, 091°04’04”W, G . Aguilar M . et al. 4713 ( MEXU); Mpio. Solosuchiapa, 2–4 km below Ixhuatán toward Pichucalco, [ca. 17°18’47.23”N, 093°00’11.57”W], D. Breedlove 24177 ( DS, ENCB, MO, NY), 29799 ( DS, LL, MEXU, MICH, MO, RSA), D. Breedlove & F . Almeda 56805 ( CAS, ENCB, LL, NY); Mpio. Berriozábal, 13 km N of Berriozábal near Pozo Turripache and Finca El Suspiro, [ca. 16°52’25.01”N, 093°19’8.64”W], D. Breedlove 24803 ( DS, ENCB, MO), D. Breedlove & T . Daniel 70879 ( CAS), cultivated plants of this collection grown from cuttings in San Francisco, California, 70879cv ( CAS), D. Breedlove & R . Thorne 30786 ( DS, ENCB, MO), D. Breedlove et al. 66158 ( CAS); Mpio. Palenque, near Agua Azul, D. Breedlove 56091 ( CAS, LL, MEXU); Mpio. Ocosingo , near ruins of Bonampak at jct. road from Lacanjá to Echeverría and road from Chancalá , [ca. 16°48’04.57”N, 091°06’21.97”W], D. Breedlove & F . Almeda 58020 ( CAS, LL, MEXU, MO); Mpio. San Fernando, 20 km NW of San Fernando just beyond Colonia Cuahtémoc , [ca. 16°58’42.74”N, 093°20’28.46”W], D. Breedlove & M . Bourell 68269 ( CAS); Mpio. Ocosingo, 70 km SW of Palenque toward Ocosingo along the Jol Uk’um , [ca. 17°10’48.02”N, 092°06’39.86”W], D. Breedlove & B . Keller 49526 ( CAS, MEXU, MO); Mpio. Ocozocoautla de Espinosa, 26–28 km N of Ocozocoautla toward Mal Paso , [ca. 16°56’22.87”N, 093°27’55.46”W], D. Breedlove & A . Smith 22469 ( DS, MEXU, MICH, MO, RSA); Mpio. Ocosingo , 4 km E del crucero San Javier , 16°48’44”N, 091°03’13”W, J . Calónico S . et al. 25022 ( ENCB, MEXU); Mpio. Berriozábal , ca. 12 km NW of Berriozábal, ca. 16°51’N, 093°19’W, T . Daniel 8375 ( CAS, MEXU); Mpio. Ishuatán, carretera 195, 45 km N [ S] de Pichucalco, [ca. 17°18’26.14”N, 093°00’27.05”W], S . Gliessman 77-7 ( MEXU); Mpio. Pichucalco, 20 km Teapa – Pichucalco , [ca. 17°32’45.83”N, 093°04’44.80”W], M . Ishiki et al. 2035 ( CAS); Mpio. Ocosingo, Lacandona de Lacanhá–Chansayab, 130 km SE de Palenque, por la carretera fronteriza hasta el crucero San Javier , después 8 km hacia el oeste, 16°44’N, 091°05’W, S . Levy T. & A . Durán F . 398 ( MEXU); Mpio. Berriozábal , 12 km N de Berriozábal, E . Martínez S. & M . Soto 24216 ( MEXU); Mpio. Ishuatán , 9 km N de Tapilula, [ca. 17°17’16.71”N, 093°00’38.70”W], E . Martínez S . et al. 3198 ( CAS, ENCB, MEXU, MO, WIS); Mpio. Yajalón, Yajalón–Petalsinco , carretera de terraceria KM 5 , A . Méndez T. [= A. Ton] 7134 ( IEB, MEXU, MO, RSA, XAL); Mpio. Ocozocoautla, 9 km NW de Emilio Rabasa, 500 m W de El Aguajito , 16°57’32”N, 093°40’31”W, S . Ochoa G . 3860 ( XAL); Mpio. San Fernando , cerros adelante de Col. Cuauhtémoc, [ca. 16°56’39.34”N, 093°13’33.83”W], E . Palacios E . 385 ( CAS); Mpio. Ocozocoautla , Reserva El Ocote, al O mas adelante de la caseta, E. Palacios E . 9631 ( CAS); Mpio. San Fernando , 1.4 km N de Cuauhtémoc, 16°56’32”N, 093°13’30”W, R . Palestina 1747 ( XAL); Mpio. Ocosingo, Lacanjá – Chansayab, Vereda de Pancho López Kin , B . Paniagua 539 ( MEXU); Mpio. Berriozábal , 13 km N de Berriozábal, O . Téllez V . et al. 7591 ( MEXU); Mpio. Yajalón, Yajalón–Petalzinco , [ca. 17°12’13.88”N, 092°23’17.85”W], A . Ton 7134 ( XAL); Mpio. Tila, Finca Morelia , [ca. 17°17’13.71”N, 092°26’08.79”W], A . Ton 7427 ( MEXU). Oaxaca: Mpio. San Pedro Ixcatlán , Cerro Camarón, al W de Cerro Quemado, J . Calzada 10293 ( XAL); Mpio. Chiltepec, Ejido de Rancho Faisán, vereda para La Rejoya, [ca. 17°56’57.43”N, 096°09’47.56”W], J . Calzada 14456 ( CAS, MEXU); Mpio. San Miguel Soyaltepec , Cerro Tepezcuintle, J . Calzada & S . Anta 17515 ( MEXU); Mpio. San Felipe Usila , 2 km del poblado Cerro Verde, carretera al campamento Arroyo Tambor, J . Calzada et al. 16579 ( MEXU); Distr. Tuxtepec, Presa Temazcal , camino Temazcal – Vertedor a 6 km, L . Cortes & R . Torres C . 66 ( ENCB, MEXU); Mpio. Soyaltepec , 2 km de la Hidroelectrica al Vertedor de la Presa Temascal, L . Cortes & R . Torres C . 617 ( MEXU); Distr. Tuxtepec, Mpio. Acatlán , Cerro Buenos Aires, lado oeste de la Presa Temazcal (Miguel Alemán), L . Cortes et al. 165 ( ARIZ, CAS, MEXU); Uxpanapa Region, E of Sarabia toward Uxpanapa , 4.2 mi NE of Río Corte, 17°09’N, 095°15’W, T . Croat & D. Hannon 63176 ( CAS, DUKE, MEXU, MO, TEX); Mpio. San Miguel Soyaltepec, Cerro Tepezcuintle, 18°09’34.1”N, 096°20’50.5”W, C . Cruz E. & G . Juárez G . 2599 ( MEXU, SERO); Mpio. Santa María Chimalapa, Matías Romero, Colonia Cuauhtémoc , [ca. 17°06’06.64”N], A . Delgado S . 942 ( ENCB, MEXU, US); Mpio. San Felipe Usila, Cerro Verde , [ca. 17°53’13.44”N, 096°30’05.71”W], A . Hanan A. & R . de Santiago 854 ( MEXU, SERO); Mpio. Santa María Chimalapa, ca. 10 km O de Sta. María por la vereda a Chicosaja , 16°53’N, 094°46’W, H . Hernández G . 1054 ( CAS, ENCB, MEXU, MO, XAL); Mpio. San Felipe Usila, Cerro Verde , 8 km NNE of San Felipe Usila, 17°57’N, 096°30’W, G . Ibarra M. et al. 3758 ( BM, MEXU, MO, SERO); Mpio. San Felipe Usila, Nueva Santa Flora , 17°55’N, 096°26’W, G . Ibarra M. et al. 3765 ( BM, MEXU, MO, SERO); Distr. Tuxtepec, Mpio. Ayotzintepec, 3.7 km NE de Ayotzintepec, Cerro Cueva de los Duendes , 17°42’26”N, 096°07’59”W, G . Juárez G . 3771 ( SERO); Mpio. Santa María Tlalixtac, Río Cóndor , brecha entre Santa María Tlalixtac y Chiquihuitlán de Benito Juárez, 17°57’14.5”N, 096°43’4.5”W, G . Juárez G. & C . Cruz E . 937 ( SERO, MEXU); Mpio. San Miguel Soyaltepec, Cerro Tepezcuintle, Papaloapam , 18°08’46.6”N, 096°21’37.3”W, G . Juárez G. & A . Martínez F . 788 ( SERO, MEXU); Mpio. Matías Romero, Río Coatzacoalcos at Cuauhtémoc , 18 km ESE of Palomares, 17°06’N, 094°53’W, M . Nee 29710 ( F, NY, XAL); Distr. Tuxtepec , “Cerro de la Cruz” near Temascal, E arm of Presa Alemán, 18°13’N, 096°24’W, D. Neill 5399 ( CAS, MEXU, MO); Mpio. Santa María Jacatepec, predio La Joya del Obispo , [ca. 17°51’33.80”N, 096°11’53.88”W], C . Ramos & E . Martínez S . 620 ( MEXU); Santa María Chilchotla, Cuahtémoc, ca. 4 km NE of Santa María Chilchotla, near Clemencia and Sta . Rosa, 18°14’N, 096°50’W, S . Solheim & S . Reisfield 1363 ( MEXU, NY, XAL, WIS); Mpio. San Pedro Ixcatlán, Sierra Mazateca , Cerro Camarón, 1 km E of village of Cerro Quemado , 18°09’N, 096°35’W, S . Solheim & S . Reisfield 1499 ( MEXU, XAL, WIS); Distr. Tuxtepec, Presa Miguel Alemán , Cerro de la Cruz, [ca. 18°12’20.03”N, 096°25’35.09”W], R . Torres C . et al. 2133 ( MO); Distr. Tuxtepec, Mpio. Santa María Jacatepec, camino a Cosolapa San Antonio, Ejido de San Felipe Tilpa , 13.3 km SO de La Reforma, 17°51’N, 096°03’W, R . Torres C. & L . Cortes A . 11480 ( CAS, MEXU); Mpio. Santa María Jacatepec, bajada del predio El Aguila a San Agustín, entrada por La Reforma , 28 km SW de Tuxtepec, carr. a Matías Romero, 17°50’N, 96°06’W, R . Torres C. & E . Martínez S . 11093 ( IEB, MEXU, MO, TEX); Mpio. Matías Romero , 7.2 km O de Esmeralda, 17°08’N, 094°50’W, T . Wendt et al. 3614 ( ARIZ, CAS, ENCB, LSU, MEXU, MO, NY, TEX, XAL). Puebla: Mpio. San Sebastián Tlacotepec, 18°26’12”N, 096°50’31.8”W, L . Caamaño O . 6602 (HUAP-image seen). Tabasco: Mpio. Teapa, 0.34 km E de la Univ. Aut. Chapingo, 17°31’31”N, 092°55’33”W, J . Calónico S . et al. 21459 ( BM, MEXU); Mpio. Teapa, Cerro del Madrigal, 3 km E de Teapa, camino a Talcotalpa , 17°35’42”N, 092°55’26”W, R . Fernández N . 2214 ( ENCB, RSA); Mpio. Teapa, Sierra El Madrigal, Centro Regional Tropical Puyacatengo de la Univ. Autónoma de Chapingo , 17°31’02”– 17°32’30”N, 092°54’10”– 092°56’W, A . Hanan A . et al. 326 ( MEXU); Mpio. Tacotalpa, 3.2 km después de cruzar la panga del Río Oxiolotán , yendo de Tapijulapa a Oxoiotán, 17°26’30”N, 092°45’30”W, S . Hernández & A . Espejo 139 ( ENCB, IEB, MEXU, MO, XAL); Mpio. Macuspana, Parque Nac. Agua Blanca , KM 64 carretera Villahermosa – Escárcega, 17°38’N, 092°30’W, M . López P . et al. 3 ( ENCB, XAL); Mpio. Teapa , KM 6 de la entrada al ejido La Unión hacia Ixtapangajoya, [ca. 17°33’34”N, 092°57’39”W], M . Magaña & A . Suárez F . 724 ( ENCB, MEXU, XAL); Mpio. Macuspana, Centro Recreativo Agua Blanca , [ca. 17°41’15”N, 092°27’42”W], M . Magaña et al. 1198 ( ENCB, MEXU, XAL); Mpio. Macuspana, Parque Nac. Agua Blanca , KM 64 carretera Villahermosa – Escárcega, 17°38’N, 092°30’W, L . Martínez G . 12 ( ENCB, MEXU); Mpio. Teapa, Cerro Madrigal, 500 m E de Puyacatengo , Univ. Aut. Chapingo , 17°31’34”N, 092°55’17”W, E . Martinez S . et al. 34736 ( BM, MEXU); Mpio. Teapa , 1 km NE de Puyacatengo, 17°31’39”N, 092°55’22”W, E . Martínez S . et al. 34899 ( BM, BR, CAS, FLAS, MEXU, PH); Mpio. Teapa, El Azufre, 16 km E de Teapa, 17°35’N, 092°50’W, P . Tenorio L . et al. 5577 ( ARIZ, MEXU, RSA, TEX); Mpio. Macuspana , Agua Blanca, F . Ventura A . 20941 ( CAS, ENCB, IEB, MEXU, NY); Mpio. Teapa, El Madrigal, 17°35’07”N, 092°56’21”W, F . Ventura A . 20989 ( ENCB, MEXU, NY, XAL); Mpio. Macuspana, Agua Blanca , S . Zamudio 183 ( XAL). Veracruz: Mpio. Cuichapa , carretera de terracería entre Cuichapa y Omealca [ca. 18°45’51.96”N, 096°49’53.57”W], J . Calzada & A . Vovides 2396 ( ENCB, F, MEXU, MO, XAL); Mpio. Jesús Carranza , KM 6 del camino Cedillo – Río Alegre , 17°10’N, 094°40’W, B . Dorantes 3917 ( ENCB, MEXU, XAL); Mpio. Hidalgotitlán, kms 0–2 del camino Plan de Arroyos–Alvaro Obregón , 17°15’N, 094°40’W, J . Dorantes et al. 2801 ( ENCB, F, NY, XAL); Mpio. Hidalgotitlán, 0–2 km del Campo Cedillo, rumbo a Río Alegre , 17°19’N, 094°40’W, J . Dorantes et al. 2936 ( F, XAL); Mpio. Jesús Carranza , KM 10 del camino Cedillo – Fco. Villa, 17°10’N, 094°40’W, J . Dorantes et al. 3938 ( ENCB, F, MEXU, MO, XAL); Mpio. Hidalgotitlán, camino Cedillo–La Laguna, J . Dorantes et al. 4138 ( F, MEXU, XAL); Mpio. Tezonapa , 5–6 km SE de Motzorongo, 18°40’N, 096°40’W, R . Gobles G . 208 ( XAL), 299 ( XAL); Mpio. Hidalgotitlán , 3 km SW of Campamento La Laguna, 17°16’N, 094°32’W, M . Nee 29995 ( F, MEXU, NY, XAL); Mpio. Amatlán de los Reyes, Cerro de Amatlán [ca. 18°49’53.93”N, 096°54’3.08”W], H . Oliva & V . Villar 624 ( IBUG, XAL); Mpio. Coetzala , 1 km E de Coetzala, 18°46’50”N, 096°54’52”W, A . Rincón G. & C . Durán E . 1508 ( MEXU, XAL); Mpio. Hidalgotitlán, Río Soloxuchil , entre Hnos. Cedillo y La Escuadra, 17°17’N, 094°38’W, M . Vásquez et al. 322 ( F); Mpio. Hidalgotitlán, brecha Hnos. Cedillo – La Laguna, B . Vázquez 17 ( F, MEXU, NY, XAL); Mpio. Jesús Carranza , 3 km E del Río Chalchijapa por la carretera Sarabia – Cedillo, M . Vázquez T . 1585 (XAL); Mpio. Jesús Carranza, 2 km N del Poblado 2, Ejido F. J . Mina, 17°16’N, 094°40’W, M . Vázquez T . et al. V-2568 ( CAS, MEXU, XAL); Chicomapa [ca. 18°33’39, 096°51’08”W], V . Vázquez T . 548 (ENCB, F, IEB, MEXU, XAL). GUATEMALA. Alta Verapaz: Mpio. Rubeltein, Montaña Sacranix, Wegstrecke zwischen der Finca Xalcata (= Saqmoc) und der Finca Sacté, S des Río Sachichaj ( W der Strasse Cobán – Chisec), H . Foerther et al. 10940 ( BM, W); Sacté , 15°30’N, 090°27’W, I . Kunkel 161 ( BR) .

Figures

FIGURE 11. Map of southern Mexico (showing states) and northern Central America with distribution of Louteridium mexicanum. Circles may pertain to multiple collections.

FIGURE 15. Louteridium mexicanum. A. Shoot with inflorescence in flower. B. Leaf. C. Flower with pedicel and enlargements showing glands on external surface of corolla and eglandular trichomes on pedicel. D. Posterior calyx lobe. E. Lateral calyx lobe (adaxial surface with enlargement showing glandular punctations and cystoliths). F. Corolla dissected to show insertion of stamens. G. Anther. H. Distal portion of style and stigma. I. Capsule. J. Seed. A-H from Breedlove & Daniel 70879cv, I from Breedlove 24177, J from Hernández G. 1054. Drawn by Erin Hunter (inverted from scratchboard).

FIGURE 1. Most likely phylogenetic hypothesis for relationships among species of Louteridium, generated from ddRADseq loci analyzed under maximum likelihood (and implemented in RAxML). Our analyses yield strong support for a monophyletic Louteridium as well as support for three primary sections: Louteridium, Parcostamium, and Tetrandrium. Hash mark between outgroups and Louteridium indicate branch was shortened to reduced overall figure width for reproducibility. Asterisks [*] indicate 100% ML bootstrap support.