Justicia zapoteca T.F. Daniel, 2017

Daniel, Thomas F., 2017, New and Reconsidered Mexican Acanthaceae XII, Proceedings of the California Academy of Sciences 64 (7), pp. 131-154 : 136-140

Justicia zapoteca T.F. Daniel , sp. nov.

Justicia zapoteca can be distinguished by the following combination of characters: leaf blades with at least the adaxial surface pubescent; inflorescences of axillary and/or terminal, pedunculate, and dichasiate spikes or panicles of dichasiate spikes; calyces unequally five-lobed, with four lobes equal to subequal in size and the posterior lobe filiform and greatly reduced in size; corollas pale red-pink (salmon) to purplish, 25‒32 mm long, and externally pubescent with glandular and eglandular trichomes; anther thecae superposed, perpendicular, dorsally pubescent, and the lower theca with a basal appendage 0.3‒ 0.5 mm long; pollen two-aperturate with apertures flanked on each side by two rows of insulae (and sometimes peninsulae as well); capsules 12‒16 mm long and pubescent with glandular an eglandular trichomes; and seeds with the testa tuberculate and with the tubercles granulate.

TYPE.— MEXICO. Oaxaca: Distr. Pochutla, Mpio. San Miguel del Puerto, ca. 13 km NW of Xadani, ca. 4 km upslope from Rancho Monte Carlo , 16°00.771ʹN, 096°06.305ʹW, 1400 m, tropical subdeciduous forest (selva mediana subperennifolia) to mesophytic montane forest, 24-II-2012 (flr, frt) , T. Daniel , E. Lott , J. Pascual , & N. Salas M. 11898 (holotype: MEXU!; isotypes; CAS!, MO!, NY!, SERO!, TEX!).

Trailing perennial herbs to erect shrubs to 3 m; young stems subquadrate and substriate to striate, internodes glabrous or sparsely 2-fariously pubescent with flexuose to antrorsely and/or retrorsely appressed eglandular trichomes to 0.7 mm long, nodes and axillary buds pubescent with eglandular trichomes. Leaves petiolate, petioles to 55 mm long, blades ovate to elliptic, 42–170 mm long, 22–101 mm wide, 1.6–2.8 × longer than wide, (rounded to) acute to acuminate at apex, truncate to rounded to acute to subattenuate at base, adaxial surface pubescent with antrorse to antrorsely appressed eglandular trichomes restricted to major veins or to midvein only, abaxial surface glabrous or very sparsely pubescent like adaxial surface, margin entire. Inflorescence of axillary and/or terminal pedunculate dichasiate spikes or panicles of dichasiate spikes to 120 mm long (including peduncle and excluding flowers), peduncles to 13 mm long, glabrous or evenly puberulent with erect eglandular and subglandular trichomes to 0.05 mm long (puberulent) and sometimes also with an overstory of erect to flexuose eglandular trichomes to 0.7 mm long, bracts subtending panicle branches ovate to linear-elliptic to subulate, 3–8 mm long, 0.3– 3 mm wide; fertile portion of individual spikes to 87 mm long and 2–3 mm wide (excluding corollas), rachis clearly visible, evenly puberulent and usually also with an overstory of erect glandular trichomes 0.1 mm long (especially distally) and sometimes also with erect to flexuose eglandular trichomes (sometimes sparse) 0.1– 0.5 mm long, or sometimes glabrous proximally; dichasia alternate (1 per node), ± secund, sessile, 1-flowered. Bracts not imbricate, opposite, subulate to lance-subulate, 2–3 mm long, 0.3– 0.6 mm wide, abaxial surface pubescent like rachis. Bracteoles linear-subulate to lance-subulate, 1.8– 2.6 mm long, 0.3– 0.5 mm wide, abaxial surface pubescent like bracts. Flowers sessile to subsessile (i.e., pedicels to 0.5 mm long). Calyx 5-lobed, 3. 5–6 mm long, abaxially pubescent like bracteoles, lobes heteromorphic (4+1, posterior lobe reduced), 4 lobes equal to subequal in size, lanceolate, 3–5 mm long, 0.6– 1 mm wide, widest near base or midpoint, posterior lobe inconspicuous, filiform, 0.4– 2 mm long, 0.05– 0.2 mm wide. Corolla pale red-pink (salmon) to purplish, 25–32 mm long, externally pubescent with erect to flexuose eglandular and glandular (sometimes sparse) trichomes 0.05– 0.2 mm long, tube 18–23 mm long, gradually expanded distally, 2.5– 3.5 mm in diameter near midpoint, upper lip 6–12 mm long, 2-fid at apex, lower lip 7–12 mm long, lobes 1–2. 5 mm long, 1–2. 2 mm wide. Stamens 8–12. 5 mm long, thecae superposed (touching or separated by a gap to 0.2 mm), perpendicular, 1.1– 1.8 mm long (including basal appendage), subequal to unequal in length, both dorsally pubescent (trichomes sometimes few or inconspicuous) with erect to flexuose eglandular trichomes to 0.1 mm long, lower theca with a spurlike to pointed basal appendage 0.3– 0.5 mm long; pollen 2-aperturate, polar diameter 55–56 μm, equatorial diameter (apertural view) 35 μm, apertures flanked on each side by 2 rows of insulae (and sometimes with peninsulae as well). Style 26–33 mm long, proximally pubescent with eglandular trichomes, stigma to 0.1 mm long, lobes not evident (appearing subcapitate) or unequally 2-lobed, 1 lobe 0.1 mm long, other lobe 0.05 mm long. Capsule 12–16 mm long, pubescent with erect to retrorse eglandular and glandular trichomes to 0.2 mm long, head 7. 5–10 mm long, with slight medial constriction. Seeds compressed, ± cordate, 2–4 mm long, 2– 2.8 mm wide, surface bubbly tuberculate, surface of tubercles granulate.

PHENOLOGY.— Flowering: November–April; fruiting: November–April. On a plant cultivat- ed out-of-doors during a period of dry and mostly sunny weather in San Francisco, California, 10 flower buds were tagged, and the times of their opening and dehiscence/falling from the plant were recorded in six hour intervals. All flowers opened between 06:00 and 08:00. They stayed open between 72 and 258 hours, with the average life span of a flower being 152 hours (6.3 days) with the population standard variation of 49.29 hours. Corollas and styles showed no obvious signs of senescence (e.g., discoloration or withering) when the former dehisced and fell from the plant.

DISTRIBUTION AND HABITATS.— Southern Mexico (central southern Oaxaca; Fig. 1 ); plants occur infrequently in the understory of evergreen seasonal forests (selva mediana subperennifolia) transitioning to mesophytic montane forests, and sometimes in coffee plantations (cafetales) therein, at elevations from 690 to 1640 meters.

ILLUSTRATIONS.— Figures 3 , 5.

CONSERVATION.— This species is known from at least six collections in the same region of the Sierra Madre del Sur in southern Oaxaca. A considerable portion of its EOO, which consists of 4.6 sq. km, lies in a region where coffee is cultivated. Given the increasing demand for coffee, such cultivation is likely to expand in the region, thereby presenting an inferred threatening event. Although the actual geographic range of this species is likely considerably larger than currently known, based on the data available, a preliminary assessment of Critically Endangered (CR) appears warranted, and is proposed for this species (B1, a, b; IUCN 2017).

PARATYPES.— MEXICO. Oaxaca: Distr. Pochutla, Mpio. San Miguel del Puerto, ca. 13 km NW of Xadani, ca. 4 km upslope from Rancho Monte Carlo , 16°00.771ʹN, 096°06.305ʹW, T . Daniel , A . Sánchez , & J . Pascual 11810 ( CAS, K, MEXU, MO, NY, RSA, SERO, US) , specimens of plants from this locality cultivated from seed of type collection in San Francisco, California, T. Daniel et al. 11898cv ( CAS); Distr. Pochutla, Mpio. San Miguel del Puerto , cafetal “Arroyo Arena,” 15°58’36.8”N, 096°05’59.7”W, A . Nava. Z . et al. 268 ( MEXU, SERO); Distr. Pochutla, Mpio. San Miguel del Puerto, Piedra de Agua , 15°57’11.2”N, 096°06’23.6”W, J . Pascual 224 ( CAS, MEXU, SERO); Distr. Pochutla, Mpio. San Miguel del Puerto , camino a El Vijia, 16°00’42.6”N, 096°06’43.6”W, J . Pascual 2326 ( MEXU, SERO); Distr. Pochutla, Mpio. San Miguel del Puerto , 150 m N de la finca Monte Carlo , 15°59’38.1”N, 096°06’22.3”W, A . Saynes V . & M . Elorza 2741 ( CAS, MEXU) .

DISCUSSION.— Rarely, the proximal-most axillary branch of a panicle bears only a single dichasium, and thus appears like an axillary pedunculate dichasium. Although not evident on living plants, at the nodes of dried plants the region of attachment of the petioles on stems is greater in diameter than the petiole and appears as a circular flange around the base of the petiole, and remains as a protruding flangelike or shieldlike leaf scar after the leaf has dehisced. This would appear to be due to considerable shrinkage of the petiole on drying.

Justicia zapoteca would appear to pertain to Graham’s (1988) section Sarotheca (Nees) Benth. based on characters of the inflorescence, calyx, and seed. Indeed, it superficially looks much like the southern Central American species, J. oerstedii Leonard , which differs by having glabrous leaf blades, bright red corollas bearing only eglandular trichomes, unappendaged and glabrous anther thecae that are equally to subequally inserted and parallel to subsagittate but separated by a connective 0.2- 0.6 mm long. Pollen of J. zapoteca ( Fig. 4C ) conforms to that occurring in several of the sections of the genus recognized by Graham (1988), and to the most commonly encountered type among Mexican species of the genus ( Daniel 1998).

Figures

FIGURE 1. Map of southern Mexico (and northern Central America, shaded) with distributions of Carlowrightia yucatanensis (Yucatán), Justicia zapoteca (Oaxaca), Poikilacanthus foliosepalus (Oaxaca), and P. pochutlensis (Oaxaca).

FIGURE 3. Photographs of Acanthaceae. Carlowrightia yucatanensis (Carnevali et al. 4381), habit (top left) and flower (top middle); Poikilacanthus pochutlensis (Daniel & de Avila 12204), apex of shoot with mature flower bud (top right) and Cerro Espino, locale of only known collections (middle right); Justicia zapoteca (Daniel et al. 11898cv), apex of shoot with inflorescence and flowers (bottom left), seed (middle center), and flower (bottom right). Photos by the author, except C. yucatanensis photos by G. Carnevali F. (used with permission).

FIGURE 5. Justicia zapoteca. A. Shoot with inflorescence. B. Leaf. C. Inflorescence node with flower. D. Bracteole. E. Bract. F. Calyx. G. Distal portion of stamen with bithecous anther. H. Capsule. I. Seed. (A, C from Daniel et al. 11898; B, H, I from Daniel et al. 11810; D–G from Saynes V. & Elorsa 2741). Drawn by Sean Edgerton.

FIGURE 4. Pollen of Acanthaceae. A, B. Carlowrightia yucatanensis (Daniel et al. 10320), apertural view (A) and interapertural view (B). C. Justicia zapoteca (Saynes V. & Elorsa 2741), apertural view. D, E. Poikilacanthus foliosepalus (Hernández O. 326), apertural view (D) and interapertural view (E). F. Louteridium dendropilosum (Fernández N. 4189). G, H. Poikilacanthus pochutlensis (Torres & Martínez 4907), subpolar view (G) and polar view (H). I. Louteridium dendropilosum (Daniel et al. 11784), with internal contents extruding via pores.