Louteridium parayi Miranda

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 : 94-96

8. Louteridium parayi Miranda , Ceiba 4:140. 1954. TYPE.— MEXICO. Chiapas: cerca del Suspiro, unos 9 km NO de Berriozábal [ca. 16°52’36.21”N, 093°19’34.53”W], 950 m, selva alta siempre verde, 9-VI-1953 (flr, frt), L. Paray & F. Miranda 7834 (holotype: MEXU-00029822!; isotypes: F!, MEXU-00029828!).

Shrubs or trees to 3 m tall, epiphytic or epipetric. Older (woody) stems subquadrate to subterete, lenticellate, lacking trichomes; younger (herbaceous) stems quadrate-sulcate, glabrous. Leaves not all seasonally deciduous, evenly distributed along stems, petiolate, petioles to 20 mm long, blades coriaceous-subsucculent, oblanceolate to obovate, 50–200 mm long, 15–63 mm wide, 3.3–5 × longer than wide, acute-apiculate (to caudate) at apex, attenuate to long-attenuate at base, adaxial surface glabrous, abaxial surface with scattered flexuose to antrorse eglandular trichomes to 1 mm long (or sometimes nearly glabrous), margin entire. Inflorescence a terminal pedunculate thyrse to 27 cm long (including peduncle and excluding corollas), peduncle 3. 5–15 cm long, glabrous, rachis glabrous; dichasia modified by sympodial expansion and appearing like dichotomous branches with zig-zag nodes, alternate, pedunculate, 1–many-flowered, to 100 mm long (excluding corollas), dichasial peduncles to 55 mm long, glabrous. Bracts caducous, lance-ovate to elliptic, 7–15 mm long, 4–8 mm wide, abaxially glabrous. Bracteoles and secondary bracteoles persistent, ovate to ovate-elliptic to broadly elliptic, 6–11 mm long, 5–7. 5 mm wide, abaxially glabrous (or inconspicuously glandular-punctate), those of a pair connate along one side for up to 1/2 their length and proximally subsaccate, sometimes conspicuously imbricate. Flowers pedicellate, pedicels to 30 mm long, glabrous. Calyx 24–39 (– 48 in fruit) mm long, lobes heteromorphic, apparently subsucculent, abaxially glabrous, posterior lobe conduplicate, oblong to subelliptic to oblanceolate, 22–45 mm long, longer than lateral lobes, 7. 5–14 mm wide, saccate or with a flap-like appendage to 2.5 mm long at base, rounded to acute at apex, lateral lobes lance-ovate to lance-linear to linear-oblong, 19–44 mm long, 5–8. 8 mm wide, acute at apex. Corolla pale greenish, 45– 72 mm long, externally glabrous, tube 25–35 mm long, narrow proximal portion of tube 0.5– 3 mm long, 6–8. 5 mm in diameter near midpoint, throat 24–33 mm long, 28–40 mm in diameter at mouth, lobes spreading to recurved, subtriangular to broadly ovate, 8–21 mm long, 10–17 mm wide, rounded and emarginate at apex. Stamens 2, 70–90 mm long, filaments glabrous distally, densely pubescent at base with eglandular trichomes, thecae 13–17 mm long; staminodes (if present) not seen. Style 74–90 mm long, glabrous, stigma unequally 2-lobed, lobes ovate to linear-elliptic to linear-oblanceolate, 2. 5–6 mm long, 1.1–2. 8 mm wide. Capsule 27–40 mm long, 5.5–7. 2 mm in diameter, glabrous, stipe 5–13 mm long. Seeds up to 18 per capsule, 4.5– 5 mm long, 4.3–4. 5 mm wide, surfaces smooth or with irregular ridges.

PHENOLOGY.— Flowering: April–December; fruiting: June–December. Flowers of Daniel & Wendt 5804 were observed to be fully open after dark.

DISTRIBUTION AND HABITAT.— Southern Mexico (Chiapas, Veracruz; Fig. 8 ); plants occur on slopes on limestone (often karstic) in lowland rain forests, lower montane rain forests, and montane rain forests at elevations from 100 to 1500 meters.

ILLUSTRATIONS.— Figures 4G, H, 16 ; Miranda (1954:141).

CONSERVATION.— Louteridium parayi has an EOO of 2,210 km 2. Plants occur in at least one large protected area in Chiapas, and the EOO includes another small one in Verazcruz. Frequency information on collections varies from locally infrequent to locally frequent. Known occurrences reveal two subpopulations separated by ca. 110 km. Historical landsat imagery (1984 to 2017) via Google Earth Pro (2018) reveals that the habitat of the western subpopulation in the Uxpanapa region of Veracruz has undergone extensive conversion from forested land to local agriculture and pasturage. The same imagery does not clearly show a similar large-scale conversion of forest in the region of the eastern subpopulation in Chiapas. Thus, there are two locations, in one of which a threat is evident. Based on these data, a preliminary conservation assessment of Endangered (EN; B1, a, b; IUCN 2017) is proposed.

DISCUSSION.— Although a single specimen was cited in the protologue, and Miranda (1954:125) indicated that the types of plants described in his publication were deposited at MEXU, there are two specimens of Paray & Miranda 7834 in that herbarium. On one of them, “tipo” is written in the same handwriting as the rest of the label (i.e., by Miranda), and in his 1955 note on this specimen Miranda indicated that flowers and part of the inflorescence were lost from the specimen. In his note, he also refers to the isotype, which contains flowers and an inflorescence. Therefore, it seems clear that the sheet bearing “tipo” is the holotype, as indicated above .

Louteridium parayi is perhaps the most morphologically distinctive species in the genus. It possesses several unusual or unique characteristics: posterior lobe of the calyx subsaccate or with a basal appendage to 2.5 mm, a highly modified inflorescence, fused and basally subsaccate bracteoles, narrow proximal portion of the corolla tube very short to nearly nonexistent, and leathery oblanceolate to obovate leaves. The modified inflorescence of this species appears to be a thyrse, but because the lateral and modified dichasia are alternate (i.e., only one per node of the rachis), the thyrse appears dichotomously branched. The major branches in the inflorescence are interpret- ed as dichasial lateral branches that expand through non-symmetrical sympodial growth into often elongate and somewhat zig-zag “dichasial shoots.” The inflorescence terminates in a dichasium.

Although no staminodes were seen in several dissections of corollas, it is possible that one or more small appendagelike staminodes could not be discerned among the dense trichomes at the base of the filaments. Indeed, an aberrant bud with extra corolla lobes possessed three fully formed stamens.

ADDITIONAL SPECIMENS EXAMINED.— MEXICO. Chiapas: Mpio. Berriozábal, 13 km N of Berriozábal near Pozo Turipache and Finca Suspiro , [ca. 16°52’10.30”N, 093°17’21.61”W], D. Breedlove 20260 ( DS), 24816 ( DS, F, MICH, MO, NY, RSA), 26336 ( DS, ENCB), 67024 ( BR, CAS, MEXU, MO, US), D. Breedlove & T . Daniel 70889 ( CAS), D. Breedlove & R . Thorne 30789 ( DS, ENCB, LL, MO); Mpio. Ocozocoautla de Espinosa, 30 km NW of Ocozocoautla, Cerro del Ocote, [ca. 16°55’51.78”N, 093°28’15.37”W], D. Breedlove 28970 ( DS, ENCB); Mpio. Ocozocoautla , Reserva del Ocote , Cerro La Colmena , al NE del Rancho Corocito, J . Calzada et al. 9623 ( F, MEXU, XAL); Mpio. Berriozábal, entre Col. Vista Hermosa y Rancho Flor de Corazón , [ca. 16°54’25.98”N, 093°26’56.10”W], E . Palacios E . 1727 ( CAS, IBUG, MEXU); El Suspiro, cerca de Berriozábal , [ca. 16°50’33.95”N, 093°18’07.62”W], L . Paray 204 ( ENCB); Mpio. Ocozocoautla de Espinosa, Cerro El Banadero, 7 km carr. Horizonte–El Ciprés , 16°53’N, 093°32’W, F . Vázquez B . 952 ( MEXU, XAL). Veracruz. Mpio. Jésus Carranza, Zona de Uxpanapa, ca. 1 km S of Sarabia – Uxpanapa road toward pueblo of Río Alegre , [ca. 17°12’07.46”N, 094°41’34.34”W], T . Daniel & T . Wendt 5804 ( CAS, DUKE, K, MEXU, MICH); Mpio. Minatitlán, Zona de Uxpanapa , 13.7 km E of La Laguna toward Uxpanapa, then 6.5 km N toward Belisario Domínguez , [ca. 17°18’47.80”N, 094°23’55.68”W], T . Daniel & T . Wendt 5805 ( CAS); Mpio. Hidalgotitlán, Hnos. Cedillo–La Escuadra, por el Río Soloxuchil , 17°16’N, 094°37’W, B . Dorantes 957 ( ENCB); Mpio. Hidalgotitlán, 0–2 km del camino Plan de Arroyios–Alvaro Obregón , 17°15’N, 094°40’W, B . Dorantes 2850 ( F, XAL); Mpio. Hidalgotitlán , KM 3 camino a La Escuadra , 17°15’N, 094°40’W, B . Dorantes 3466 ( ENCB, XAL); Mpio. Hidalgotitlán , KM 2 Plan de Arroyo–Río Alegre , 17°15’N, 094°40’W, J . Dorantes 3040 ( ENCB, IBUG, IEB, MEXU, XAL); Mpio. Hidalgotitlán, Camino Campto. Hnos. Cedillo–Plan de Arroyo , J . Dorantes 3625 ( XAL, WIS); Uspanapas , 14 km E of Campamento La Laguna (Poblado D. S.), 7.5 km N along small road through rubber plantation, [ca. 17°18’48.43”N, 094°23’56.21”W], B . Hammel & M . Merello 15573 ( CAS, ENCB, MO); Mpio. Uxpanapa , a 13.8 km E de La Laguna por la terracería a Uxpanapa, luego 6.8 km N por el camino a Belisario Domínguez , 17°18’48”N, 094°23’56”W, M . Ishiki et al. 2230 ( K, MEXU, US); Mpio. Hidalgotitlán, Hnos. Cedillo–La Escuadra por el Río Soloxuchil , 17°16’N, 094°37’W, M . Vázquez T . 957 ( ENCB, UC, XAL); Mpio. Jésus Carranza , 2 km N del Poblado 2, Ejido F. J . Mina , 17°16’N, 094°40’W, M . Vázquez 2617 ( CAS), M . Vázquez et al. V-2566 ( CAS, MEXU, MO, XAL); Mpio. Minatitlán , 6.6 km N de la terracería La Langua–Río Grande, sobre el camino nuevo a Ejido Belisario Domínguez , el cual sale de la terracería 14.7 km E de La Laguna, 17°20’N, 094°22’W, T . Wendt & A . Villalobos C . 2540 (CAS, ENCB, LSU, MEXU).

Figures

FIGURE 8. Map of Mexico (showing states) and northern Central America with distributions of species of Louteridium endemic to Mexico: L. brevicalyx, L. dendropilosum, L. koelzii, L. parayi, L. rzedowskianum, and L. tamaulipense. Sym- bols may pertain to multiple collections.

FIGURE 16. Louteridium parayi. A. Habit (Breedlove 67024). B. Bracteoles and flower (Breedlove & Thorne 30789). C. Calyx (Breedlove 28970). D. Corolla bud opened to show stamens (Breedlove 67024). E. Stigma (Breedlove 67024). F. Dehisced capsule (Breedlove 28970). G. Seed (Breedlove 28970). Drawn by Ellen del Valle.