Lachemilla cyanea D.F.Morales-B. & Romol., 2019

Morales-Briones, Diego F., Romoleroux, Katya & Tank, David C., 2019, Three new species of Lachemilla (Rosaceae) from South America, PhytoKeys 127, pp. 93-119 : 93

Lachemilla cyanea D.F.Morales-B. & Romol. sp. nov. Figs 10 , 11 , 12

Diagnosis.

Lachemilla cyanea differs from L. ranunculoides (L.M. Perry) Rothm. and L. williamsii (L.M. Perry) Rothm by its hirsute pubescence, reniform basal leaves that have a blue-green color, and turbinate-campanulate hypanthium.

Type.

PERU. Apurímac: Abancay Province, road Abancay - Cuzco, 23 km from Abancay, 13.59722S, 72.84083W, alt. 3423 m, 25 June 2012, Morales-Briones D.F. & Uribe-Convers S. 246, (holotype: ID!, isotypes: HAO!, QCA!).

Description.

Rosette herbs up to 10 cm long, branches decumbent, sparsely hirsute. Basal stipules 10 mm long, adnate to the petiole, sparsely hirsute, membranaceous, brown at base, free at apex. Basal leaves tri-parted, blade reniform in outline, 17-20 × 25-26 mm, 3 lobes, chartaceous, slightly plicate, lobes unequally obovate-rhomboid, lateral lobes divided the length 1/2 of the blade, margin dentate-incised, teeth 8-10 on each of the lobes, lower and upper surface sparsely hirsute-villous; basal petiole 12-20 mm long. Distal stipules 7-8 mm long, connate and adnate to the petiole at base, free and incised at apex, leaf-like in texture. Distal leaves tri-parted, 8-10 × 8-12 mm, lobes obovate-rhomboid, decreasing in size; distal petiole 1-2.5 mm long. Inflorescences axilar or terminal glomerulate cymes, flowers aggregate at the distal part. Floral bracts 1-2 mm long, free, incised, and ascending to slightly spreading; 2-6 flowers per inflorescence; pedicels 0.6-1 mm long, sericeous. Flowers 2-2.5 mm long; hypanthium turbinate-campanulate, green, glabrous outside and within; 4 episepals and sepals green to reddish at apex, straight, abaxially and adaxially glabrous; episepals triangular, 0.7-0.8 × 0.3-0.4 mm, apex acute; sepals triangular-ovate, 0.7-0.8 × 0.5 mm, apex acute; stamens 2 adnate to the floral disc; carpels 2, stigma clavate. Two achenes, ca. 1 × 0.7-0.8 mm, globose-ovoid.

Distribution and ecology.

Lachemilla cyanea is only known from the Province of Abancay in the Department of Apurímac at ca. 3420 m in southern Peru ( Fig. 6 ). This species occurs in the transition zone between the montane forest and the high-elevation grassland dominated by dwarf shrubs and herbs. This species lives in sympatry with L. aphanoides and L. fulvescens . It was collected in flower and fruit in late June.

Etymology.

The specific epithet refers to the blue-green color of the leaves.

Conservation status.

Lachemilla cyanea is only known from the type locality in a zone severely impacted by human activities, including conversion to agriculture. Following the IUCN (2017) guidelines, based on the reduced geographic distribution and altered land use at the type locality, this species should be categorized as endangered (EN), at least until other populations are discovered.

Notes.

Lachemilla cyanea resembles L. ranunculoides in habit and glabrous flower, but differs in the reniform shape of the basal leaves in contrast to the orbicular-ovate shape of the latter. Moreover, L. cyanea has a turbinate-campanulate hypanthium while L. ranunculoides has an oblong-ventricose hypanthium. Lachemilla cyanea also resembles L. aphanoides in the tripartite basal leaves and glomerulate inflorescence, but differs in the rosette habit and decumbent branches, in contrast to the erect stems of L aphanoides . Lachemilla cyanea is also similar to L. williamsii in habit, but the former has an overall hirsute pubescence and glabrous flowers with strictly two stamens, while the latter has a general villous pubescence, and villous flowers with up to four stamens (a characteristic only known in L. williamsii ).

Figures

Figure 6. Geographic distribution of Lachemilla rothmaleriana (read triangles), L. argentea (black circles), and L. cyanea (cyan rectangle).

Figure 10. Lachemilla cyanea. A Habit B basal leaf C flowering branch D flower. Illustration by C. Rodriguez.

Figure 11. Lachemilla cyanea. A Habit B flowering branch.

Figure 12. Lachemilla cyanea. Isotype collection: Morales-Briones D. F. & Uribe-Convers S. 246 (QCA).