Justicia imparifolia J.R.I.Wood & P.Gallego, 2023

P. C., Gallego, Wood, J. R. I. & American, South, 2023, Anisophylly in South American Acanthaceae, Rheedea 33 (4), pp. 221-245 : 232-235

Justicia imparifolia J.R.I.Wood & P.Gallego , sp. nov. Fig. 6

Justicia imparifolia is a strongly anisophyllous species somewhat resembling Justicia obliqua but differing in the nearly glabrous (not pilose) leaves, relatively large bracts 11–18 mm (not 7–8 mm) in length and longer 5-lobed calyx c. 12 mm in length (not 4-lobed, c. 9 mm long).

Type: PERU, San Martin, along road from Rioja to Pedro Ruiz , S 5°40’26”, W 77°40’35”, 1170 m, 05.03.2001, H. Van der Werff et al. 16764 (holo MO [ MO6991485 !]; iso USM [ USM178458 !]) .

Perennial anisophyllous herbs to 40 cm tall. Stems at first decumbent and rooting at nodes, glabrous to very shortly bifariously stiffly pubescent. Leaves shortly petiolate, very unequal, glabrous except for a few crisped hairs on veins beneath, margins crenulate; larger leaves 2–4.2 × 1–2.1 cm, asymmetric, very narrowly oblong-elliptic, narrowed to an oblique cuneate base and obtuse weakly falcate apex; smaller leaves subsessile, obliquely ovate to suborbicular, 0.5–1 cm in diam. Petioles 1–2 mm, crisped pubescent. Inflorescence of subsessile, terminal spikes. Bracts foliose, 11–18 × 2–3 mm, narrowly oblong-elliptic, subacute, subglabrous to thinly pilose. Bracteoles c. 11 × 1.5 mm, oblong. Calyx 5-lobed, lobes slightly unequal, outer two c. 12 × 1.75, sparsely pubescent, inner three c. 11 × 1 mm, nearly glabrous. Corolla 2.6 cm long, blue, pubescent on exterior, 2-lipped, tube 12–13 mm long, slightly widened from 1.5 mm at base to 2.5 mm, upper lip 10–12 mm long, lower lip c. 9 mm long, deflexed, 3-lobed, lobes c. 2 × 1 mm, oblong, rounded. Stamens included in upper lip, filaments 11–12 mm long, white, glabrous; anthers bithecous; thecae ellipsoid, c. 0.75 × 0.5 mm, superposed, lower theca with a very small basal appendage. Ovary narrowly ovoid, 5 mm long, glabrous; style 10–11 mm long, glabrous. Capsule c. 9 × 2 mm, glabrous, clavate, 4-seeded. Seeds not seen.

Flowering & fruiting: Found in flower and fruit in March and April.

Habitat: Low forest in a limestone area with a thick humus layer at 1170–1972 m.

Distribution: Endemic to Peru in the zone between Rioja and Pedro Ruíz in San Martin and a nearby area of Amazonas from where all four collections come ( Fig. 4 ).

Etymology: The name imparifolia refers to the very unequal leaves which are a characteristic of this species.

Specimens examined: PERU, Amazonas, Prov. Utcubamba, Bagua Grande , entre Vista Hermosay Santa Clara, S 5°53’58”, W 78°25’46”, 1972 m, A. Orejuela et al. 2716 (E n.v., USM) . San Martin, Rioja , along road Rioja–Pedro Ruiz, S 5°40’27”, W 77°40’35”, 1170 m, 23.03.1998, H. Van der Werff et al. 15525 (F, MO, US) ; Aguas Verdes , S 5°40’, W 77°40’, 02.04.2001, H. Van der Werff et al. 16611 ( MO, USM) .

Conservation status: All four collections come from the same area, three possibly from the same population. There is no information about the size of the populations nor the conservation state of the forest where it grows. Any conservation assessment other than Data Deficient ( DD) would be premature.

The Justicia candelariae (Oerst.) Leonard complex

The following two species are part of a complex of neotropical species of which Justicia candelariae (including J.chlorostachya Leonard ) is the best known. This includes Justicia angustibracteata Leonard and J. pittieri Lindau from Central America, J. neurochlamys Leonard from Colombia, J. riopalenquensis Wassh. from Ecuador, J. loretensis Lindau from Peru and J. longiacuminata Rusby from Bolivia. All of these species share the oblong(-lanceolate), green, pilose or ciliate bracts of J. tarapotensis and J. impar but are immediately distinguished inter alia by their isophylly or at most weak anisophylly. All tend to have a reduced fifth calyx lobe and some, J. chlorostachya ( Leonard, 1951 –1958) for example, are usually reported to have a 4-lobed calyx. J. yurimaguensis Lindau and J. ruiziana (Nees) Lindau would also appear to belong to this complex although their bracts are ovate/suborbicular; they both exhibit a tendency towards anisophylly.

The following two species are strongly anisophyllous:

Figures

Fig. 6. Justicia imparifolia J.R.I.Wood & P.Gallego: a. Habit; b. Leaf; c. Detail of abaxial surface of leaf; d. Bract; e. Bracteole; f. Calyx; g. Corolla opened out to show androecium; h. Anthers; i. Capsule; j. Open valve of capsule (a–c from Van der Werff 16764; d–j from Van der Werff 16611. Drawn by Margaret Tebbs).

Fig. 4. Distributionof selected anisophyllous species ofJusticia L.inPeru:J.impar J.R.I.Wood& P.Gallego(greensquares);J.imparifolia J.R.I.Wood & P.Gallego (red circles); J. microcalyx J.R.I.Wood & P.Gallego (pale brown triangle); J. obliqua J.R.I.Wood & P.Gallego (violet diamonds). Map prepared using QGIS v.3.28.2 (QGIS Development Team, 2023).