Justicia matudae T.F. Daniel, 2019

Daniel, Thomas F., 2019, New and Reconsidered Mexican Acanthaceae XIII. Justicia, Proceedings of the California Academy of Sciences 66 (3), pp. 61-85 : 67-69

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

TYPE.— MEXICO. México: Distr . V. de Bravo, Otzoloapan, [ca. 19°07′08′′N, 100°17′18′′W], ladera húmeda, matorral bajo, 1300 m, 5-IX-1954 (flr) , E. Matuda et al. 31440 (holotype: MEXU!; isotypes: ARIZ!, CAS!, CODAGEM-images only) . Figures 4–6 .

Shrubs to 1.5 m tall. Young stems ± evenly and ± densely pubescent with mostly antrorse or retrorse (also including erect to flexuose) eglandular trichomes 0.1–1.3 mm long, or with 2 ± conspicuous bands of denser trichomes and with additional trichomes between the bands. Leaves subsessile to short-petiolate, petioles 2–7 mm long, blades broadly ovate to ovate (to elliptic), 26–95 mm long, 11–58 mm wide, 1.4–3.2 × longer than wide, sometimes reduced in size distally, acute to acuminate at apex, subcordate to rounded to acute at base, adaxial surface pubescent throughout (denser on younger growth) with antrorse to antrorsely appressed eglandular trichomes 0.05–0.8 mm long, abaxial surface densely pubescent throughout with antrorse (to flexuose) eglandular trichomes to 1 mm long, dense clusters of trichomes at junctions of midvein and secondary lateral veins not evident (if possibly present, then inconspicuous), margin ± entire, ciliate from base to apex. Inflorescence of axillary and terminal dense headlike dichasiate clusters (± appearing like verticels, especially at apex of shoot; see discussion); clusters opposite at nodes, 1 (–2) per axil, multi-flowered, sessile. Bracts, green (sometimes dark colored when dry), ovate to elliptic to oblong to obovate (proximally) and becoming oblanceolate distally, 7–16 mm long, 2–9.5 mm wide, acute at apex, abaxially and marginally pubescent with mostly antrorse eglandular trichomes to 0.4 mm long, distal portion of bracts often recurved. Bracteoles obovate to oblanceolate to narrowly elliptic, 4–14 mm long, 0.6–3.2 mm wide, becoming progressively narrower from primary to tertiary pairs, abaxially and marginally pubescent like bracts, distal portion of bracteoles often recurved. Flowers sessile. Calyx 5-lobed, 6–8 mm long, lobes homomorphic, ovate to lance-ovate, 2–4 mm long, 1.1–1.7 mm wide, apically attenuate, abaxially sparsely pubescent with antrorse eglandular trichomes to 0.2 mm long, marginally ciliate with erect to flexuose eglandular trichomes to 0.8 mm long. Corolla red, 25–37 mm long, externally pubescent with flexuose to retrorse eglandular trichomes 0.1–0.6 mm long, tube gradually expanded distally, 16–20 mm long, 2.5–5 mm in diam. (measured flat) at mouth, upper lip 9–17 mm long, entire to 2-fid at apex, lower lip 9–19 mm long, 3-lobed, lobes 2–7 mm long, 1.8–4 mm wide. Stamens 8.5–15 mm long, filaments distally glabrous, proximally pubescent with eglandular trichomes, thecae of a pair subparallel to subsagittate, subequally to unequally inserted (overlapping by 1.5–2 mm), 1.9–2.5 mm long, equal to subequal in length, glabrous, lacking basal appendages. Pollen 2-aperturate, apertures consisting of a narrow colpus and a prominent central os, flanked on each side by 3–4 rows of insulae (farthest rows from aperture sometimes entirely or partially consisting of peninsulae). Style 22–27 mm long, glabrous throughout; stigma subellipsoid, 0.2 mm long. Capsules and seeds not seen.

PHENOLOGY.— Flowering: August–September; fruiting: unknown.

DISTRIBUTION AND HABITATS.— Mexico (central Michoacán and western México; Fig. 5 ); plants occur in thornscrub and tropical deciduous forest at elevations of 650–1300 m .

CONSERVATION.— Based on the five known collections of this species, the EOO = 7,530 km 2, the AOO = 20 km 2, and the greatest linear extent of its distributional range (W–E) = 250 km. Steinmann 4528 indicates that plants were uncommon at that collection site. Plants are not known from any protected areas, but at least one small protected area occurs within the EOO. At least one of the three subpopulations (the westernmost occurrence in Michoacán) is within an area threatened by active volcanoes, but threats remain unknown for the majority of the population. Based on IUCN (2017) criteria and current knowledge of the species and its threats, J. matudae is probably best assessed as Least Concern (LC).

PARATYPES.— MEXICO. Michoacán: Distr. Apatzingan, Rancho Viejo, [Mpio. Buenavista, ca. 19°12′N, 102°40′W], G . Hinton et al. 15189 ( GH, NY, US) ; Mpio. Churumuco, El Limón, Ejido Llano de Ojo de Agua , 18°43′52′′N, 101°40′28′′W, G . Ibarra M. 6764 ( MEXU); Mpio. La Huacana , ca. 2 km (air) ENE of Los Ranchos, along ridge top of Cerro El Barril, 18°42′35′′N, 102°00′00′′W, V . Steinmann 3455 ( CAS); Mpio. La Huacana, Sierra Las Cruces , 6.5 km (air) SW of Los Ranchos, Cañada Las Cruces, 18°39′59′′N, 102°03′46′′W, V . Steinmann 4528 ( CAS) .

DISCUSSION.— Leaves of Hinton et al. 15189 are beset with either prominent punctate glandlike protrusions or a parasitic infestation; because these structures are not evident on other collections of the species, they are assumed to represent the latter. The dichasiate clusters appear to be reduced dichasiate spikes (i.e., lacking an elongate rachis; thus bearing both bracts and bracteoles), but it is possible that they are compound dichasia, in which case all of the bracteal units represent bracteoles.

Justicia matudae ( Fig. 4 ) appears closely allied morphologically to J. mexiae (see below) with which it shares numerous morphological traits, including: densely clustered axillary inflorescences that appear as verticels at vegetative nodes; red corollas of similar size, shape, and pubescence; anther thecae of similar orientation and size that are glabrous and that lack basal appendages; and 2-aperturate (colporate with apertures flanked by 2 or more rows of insulae) pollen ( Fig. 6 ). Distinctions between them are noted under J. mexiae below. Justicia candicans (Nees) L.D. Benson , a widespread and variable species of the southwestern United States and western Mexico, shares some of these characteristics (e.g., corollas, anther thecae, and pollen). It differs by its less dense and rarely verticillate axillary inflorescences that sometimes form multi-flowered, short dichasiate spikes (terminating shoots or in leaf axils) or consist of solitary 1-flowered dichasia in leaf axils; narrower bracts; and corollas that usually have white markings on the lower lip.

Figures

FIGURE 4. Justicia matudae. A. Habit (Hinton et al. 15189, NY). B. Branch with inflorescences (Hinton et al. 15189, US). C. Inflorescence (Ibarra M. 6764). D. Views inside upper lip of corolla with stamens and rugula (Ibarra M. 6764). E. View of upper lip (from side) and lower lip of corolla (Ibarra M. 6764).

FIGURE 5. Map of part of southern Mexico showing distributions of Justicia amplifolia, J. matudae, J. mexiae, and J. olmeca.

FIGURE 6. Scanning electron micrographs of Justicia pollen II. A–B. Justicia totonaca (Ventura 15945). A. Apertural view. B. Interapertural view. C. Justicia mexiae, apertural view (Mexia 8732). D–F. Justicia matudae. D. Apertural view (Steinmann 4528). E. Interapertural view (Matuda et al. 31440). F. Polar view (Matuda et al. 31440). Scales = 10 µm.