Lachemilla rothmaleriana 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

publication ID	https://dx.doi.org/10.3897/phytokeys.127.36324
persistent identifier	https://treatment.plazi.org/id/7A8029F3-A117-C4CC-404C-DA1ED30DF54A
treatment provided by	PhytoKeys by Pensoft
scientific name	Lachemilla rothmaleriana D.F.Morales-B. & Romol.
status	sp. nov.

Treatment

Lachemilla rothmaleriana D.F.Morales-B. & Romol. LSID sp. nov. Figs 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5

Diagnosis.

Lachemilla rothmaleriana differs from L. hispidula (L.M. Perry) Rothm. and L. nivalis (Kunth) Rothm. by its stout stems, sericeous-villous indumentum, wide ascending sheaths with trilobate lateral lobes, and a turbinate-campanulate hypanthium.

Type.

COLOMBIA. Boyacá: Duitama. Road to páramo de la Rusia, 22 km from Duitama, before ‘fábrica de arepas Buenos Aires’, 5.92656N, 73.08826W, alt. 3650 m, 24 September 2013, Morales-Briones D.F. & Uribe-Convers S. 506. (holotype: ID!, isotypes: ANDES!, QCA!).

Description.

Ascendent subshrubs; stems erect to slightly decumbent, up to 22-27 cm long, robust, densely sericeous-villous, branched at apex. Basal stipules usually caducous, if present 5-6 mm long, adnate to the petiole at base, free at apex, entirely membranous, brown. Basal leaves usually caducous, if present 3-6-lobed, 4-6 × 3-6 mm; basal petiole 3-4 mm long. Distal leaves reduced, adnate, and connate to the distal stipules forming verticillate, lobed sheaths; sheath lobes 7-8, ascending to spreading at maturity, lanceolate, one lobe 3-5 lobate, lobes (4) 6-8 × 1-2 (4) mm, (2/3 of the entire sheath length), chartaceous, margin revolute, lower surface appressed sericeous-villous to villous, upper surface sericeous-villous to glabrescent. Inflorescences terminal or axilar ± glomerulate cymes; floral bracts lobed, ascending; 8-10 flowers per inflorescence; pedicels 0.3-0.4 mm long, pilose. Flowers 1.5-2.5 mm long; hypanthium turbinate-campanulate, brown-reddish at base, pilose-sericeous outside slightly glabrescent at base, glabrous within; 4 episepals and 4 sepals connivent to ± straight, abaxially sericeous, adaxially glabrous; episepals narrowly ovate, 0.8-1 × 0.2-0.3 mm, apex acute; sepals ovate, 0.5-1 × 0.4-0.5 mm, apex ± acute; stamens 2 adnate to the floral disc; carpels 2 (3), stigma clavate. Two achenes 0.8-0.9 × ca. 0.5 mm, subovoid.

Distribution and ecology.

Lachemilla rothmaleriana has a scattered distribution in the northcentral region of the Cordillera Oriental and in the southern part of the Cordillera Central of the Colombian Andes, between 3250 and 3768 m ( Fig. 6 View Figure 6 ). This species is mainly found in páramos dominated by bunchgrasses ( Agrostis , Calamagrostis , Chusquea ) and lives in sympatry with L. hipidula , L. nivalis , and L. purdiei . Flowering and fruiting collections dated from the months of January, May, September, and December.

Etymology.

The specific epithet honors Prof. Dr. Werner Rothmaler (1908-1962), a German botanist who studied Lachemilla in detail and described over 20 species of this genus.

Conservation status.

Lachemilla rothmaleriana is known only from the three localities that are zones 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 vulnerable (VU).

Additional specimens examined.

COLOMBIA. Putumayo: Comisaria del Putumayo, Alta cuenca del río Putumayo, filo de Cordillera entre El Encano y Sibundoy, páramo de San Antonio del Bordoncillo, 1.18333N, 77.1000W, alt. 3250 m, 4 January 1941, Cuatrecasas J. 11761 (COL, F, JE frag.). Santander: Páramo del Consuelo, Belén, Vereda de San José, 18 km from Belén on road to Encino, 6.02920N, 72.96523W, alt. 3768 m, 23 September, 2013, Morales-Briones D.F. & Uribe-Convers S. 492 (ANDES, ID, QCA).

Notes.

Lachemilla rothmaleriana resembles L. hispidula and L. nivalis by its habit and erect stems with reduced leaves that fuse with the stipules to form verticillate sheaths, but differs by having trilobate lateral lobes. Additionally, L. hispidula has an overall hispid pubescence, while L. rothmaleriana has a characteristic sericeous-villous indumentum. Moreover, L. rothmaleriana has a turbinate-campanulate hypanthium with pilose-sericeous pubescence, while L. hispidula has a globose-campanulate hypanthium with pilose-hirsute pubescence. Lachemilla nivalis has a hypanthium with similar indumentum but its shape is only slightly campanulate. In the shape of sheath lobes, L. rothmaleriana somewhat resembles L. galioides (Benth.) Rothm., but the latter has slender stems, broader sheath lobes, and villous-hispid indumentum.