Cardamine peruviana Al-Shehbaz & Marhold, 2023

Al-Shehbaz, Ihsan A. & Marhold, Karol, 2023, Cardamine peruviana (Cardamineae; Brassicaceae), a new species from Peru, Phytotaxa 594 (3), pp. 237-240 : 237

Cardamine peruviana Al-Shehbaz & Marhold , sp. nov.

Diagnosis:— Cardamine peruviana is readily distinguished from its nearest congener, C. geraniifolia , by having trifoliolate (vs. 3−5- lobed) leaflets.

Type: — PERU. Cusco, Calca, Dist. Lares, Choquecancha, Azulcocha, bosque húmedo , 12º33’ S, 72º00’W, 3823 m, 19 February 2005, L. Valenzuela , E. Suclli & J. Farfán 4976 (holotype: MO-6171648 ). Figures 1 , 2 .

Description: —Perennial herbs; rhizomes non-fleshy, with leaf scars of previous seasons. Stems 30−70 cm tall, erect or decumbent, simple at base, few branched above, glabrous. Rhizomal and lowermost cauline leaves decompound, 5−12 cm long, glabrous; petiole 2−5 cm long, basally strongly flattened and 3−6 mm wide; lateral leaflets 2−4 on each side of rachis, trifoliolate, subequaling or smaller then terminal leaflet, with petiolules 0.4−2 cm long; secondary leaflets with petiolules 2−5 mm long, broadly ovate to suborbicular in outline, lobes cuneate to oblique at base, blade incised to laciniate, ultimate teeth with a conspicuous terminal callosity to 0.3 mm long; cauline leaves 5−7, lowermost much longer than basal leaves, to 18 cm long, with petioles to 8 cm long and lateral leaflets to 6 on each side, gradually decreasing in size upward, glabrous on blade surface, sparsely puberulent subapically on distal margin with minute trichomes 0.05−0.25 mm long. Racemes 3−10- flowered, ebracteate, elongated in fruit; rachis straight; lowermost young fruiting pedicels 2.5−3 cm long, stout, ascending, straight. Sepals green, oblong, 4−5 mm long, caducous, glabrous; petals white, oblong-oblanceolate, 8−12 × 3−4 mm, apex obtuse; filaments 3.5−4.5 mm long; anthers oblong, 1−1.2 mm long. Mature fruit and seeds not seen.

Habitat:— humid forests.

Distribution:— endemic to Peru and known thus far only from the type collection.

Discussion:— Cardamine peruviana is most closely related to C. geraniifolia ( Poiret 1806: 218) Candolle (1821: 268) of Patagonian Chile and Argentina. From the latter, it is readily separated by having trifoliolate leaflets, short-petiolulate secondary leaflets, and oblong-oblanceolate petals 8−12 × 3−4 mm. By contrast, C. geraniifolia has 3−5-lobed leaflets, sessile lobes, and broadly obovate petals (0.8−) 1−1.5 cm × 4−8 mm.

The air distance between the type locality of Cardamine peruviana in Calca ( Peru) and the nearest locality of C. geraniifolia close to the Perito Moreno Glacier (Santa Cruz Province, Argentina) is about 2570 air miles (or 4316 km). Plants of this novelty grow in humid forests at elevations of ca. 3820 m, whereas those of C. geraniifolia grow in the frigid Patagonian steppes at altitudes from sea level to 600 m. A comparison between the two species in fruits, fruiting pedicels length, number of ovules/seeds per ovary/fruit, and seed morphology awaits the collection of fruiting material of the novelty.

Figures

FIGURE 1. Cardamine peruviana. Image of the holotype, Valenzuela et al. 4976 (MO-6171648).

FIGURE 2. Cardamine peruviana. A. Plant. B. Lateral leaflet of basal leaf. C. Petal. Drawn from holotype Valenzuela et al. 4976 (MO- 6171648). Cardamine geraniifolia (D−F). Lateral leaflets of basal leaves. D. Biganzoli 467 (MO-5553335). E. Goodall & Lutken 42 (MO-2572317). F. Dusén 107 (MO-1617560). All illustrated by Al-Shehbaz.