Malesherbia ardens J.F.Macbr. (1927: 117)

Weigend, Maximilian, Jossberger, Thomas & Beltrán, Hamilton, 2015, Notes on Malesherbia (Passifloraceae) in Peru: a new species from southern Peru, a new record and a first report on interspecific hybridization in Malesherbia, Phytotaxa 202 (4), pp. 250-258 : 256

4. Malesherbia ardens J.F.Macbr. (1927: 117) × arequipensis Ricardi (1961: 5) ( Figs. 4 d, f ).

Shrub to ca. 1 m, Leaves alternate, 10–25 × 5–8 mm, apex acute, base cuneate, margin irregularly pinnatisect with 5–7 lobules on each side, these coarsely dentate with 2–5 teeth, long glandular, densely pubescent. Inflorescences simple, dense racemes 3–6 cm long. Flowers axillary, pedicels 5–10 mm long, pubescent. Bracts narrowly elliptical, 5–10 × 1–3 mm, coarsely serrate, glandular and pubescent. Perianth tube cylindrical, slightly narrowed towards the base, 20–25 mm long and 3 mm wide near base, ca. 4 mm wide in median portion. Calyx lobes 5, triangular-ovate with rounded apex, 3–4 × 2–3 mm, pubescent on both sides. Petals 5, triangular-ovate with rounded apex, 3–4 × 2–3 mm, apex acute, white, pubescent especially abaxially, venation pinnate. Fruit a capsule, 25 mm long, glabrous, opening with 3 acuminate and pubescent apical valves each 5–6 mm long, seeds numerous, pale brown, ca. 1 mm, irregularly shaped.

Specimens seen: — PERU.Dept. Moquegua:Prov.General Sanchez Cerro, road Moquegua to Omate, 16˚46,291´S, 070˚55,960´W, 2800 m, old rock slide in flat area at valley bottom, with M. arequipensis and M. ardens , 14 April 2004, M. Weigend & Ch. Schwarzer 7868 (B, F, HUSA, M, USM).

Notes: —This plant was in a particularly interesting region with a very recently developed vegetation cover ( Schwarzer et al. 2010) in a population of M. ardens at the valley bottom, ca. 70 m from the next population of M. arequipensis . The specimens show a clearly intermediate expression of characters, with deeply serrate, glandular leaves similar to those of M. ardens , but differing in being much smaller (to 25 mm versus to 40 mm), with fewer lobules on each side (5–8 versus 13–25), which are more widely spaced and more clearly demarcated, reminiscent of the narrow pinnae of M. arequipensis . The flowers are intermediate in size between M. arequipensis and M. ardens , but white as in M. arequipensis , not red as in M. ardens .

There was only an invidual plant, and the seeds were evidently mal-formed, so that this is likely a sterile F1- hybrid. It is not here named as a new nothospecies. Specimens of putative parental species from the same locality as above are: M. Weigend & Ch. Schwarzer 7865 (B, HUSA, USM) of Malesherbia arequipensis , and M. Weigend & Ch. Schwarzer 7866 (B, F, HUSA, M, USM) of Malesherbia ardens .

Figures

FIGURE 4. Malesherbia hybrids. a. Malesherbia fatimae × tenuifolia, inflorescence (M. Weigend et al. 9370); b. Malesherbia fatimae × tenuifolia, leaves (M. Weigend et al. 9370); c. Profesora Fatima Cáceres Huamaní with a bunch of Malesherbia fatimae × tenuifolia and Malesherbia tenuifolia; d. Inflorescence of Malesherbia arequipensis (left), M. ardens (right), Malesherbia ardens × arequipensis (middle; same collections as in e, f, and g); e. Leaves of M. ardens (M. Weigend et al. 7866); f. Leaves of M. ardens × arequipensis (M. Weigend et al. 7868). g. Leaves of M. arequipensis (M. Weigend et al. 7865).