Thursday, January 13, 2022

[Botany • 2021] Notes on the Systematics of Cuscuta Sect. Subulatae (Subg. Grammica) with the Description of Cuscuta mantiqueirana, A New Species from Brazil


Cuscuta mantiqueirana Costea, S.S. Silva & Sim.-Bianch., 

in Costea, Silva, Simao-Bianchini, et al., 2021.

Abstract
Cuscuta mantiqueirana Costea, S.S. Silva & Sim.-Bianch. a new species from montane cloud forests of the Serra da Mantiqueira, Brazil, is described and illustrated. The morphological and phylogenetic analyses revealed that the new species belongs to sect. Subulatae of subg. Grammica. The new species is related to C. odorata var. botryoides, C. rotundiflora and C. globiflora from which it differs in narrower calyx lobes and the presence of four stomatiferous lobes or projections at the distal part of the ovary. A detailed morphological comparison with C. odorata var. botryoides, morphologically the most similar taxon, is provided along with the geographical distribution, ecology and host range of the species. The morphological and phylogenetic relationships of the new species, as well as the diversity of stomatiferous projections, are discussed in the broader context of sect. Subulatae and subg. Grammica. Cuscuta boliviana var. paranensis is considered a synonym of C. odorata var. botryoides.

Keywords: Convolvulaceae, dodders, ITS, morphology, parasitic plant, phylogeny, systematics

Habitat, habit, inflorescences and flowers of living Cuscuta mantiqueirana
 A, B montane cloud forest habitat (arrows indicate C. mantiqueirana)
C, D habit
E the most common host, Fuchsia regia
F–H inflorescences I flowers
(F–I photos: Suzana Ehlin Martins F, H Itatiaia G, I Serra do Papagaio).



Cuscuta mantiqueirana Costea, S.S.Silva, Sim.-Bianch., sp. nov.
 
Diagnosis: Cuscuta mantiqueirana is similar to C. odorata var. botryoides, C. rotundiflora and C. globiflora because of their corolla that becomes globose at fructification and their well-developed scales with numerous fimbriae, but it differs from all these taxa in narrower calyx lobes, the presence of four stomatiferous lobes or projections, 0.4–0.6 mm long at the ovary apex, which form a collar at the fruit stage, as well as 3-colpate pollen grains with reticulate tectum. It differs from C. odorata var. botryoides in the obconical pedicels and larger flowers, 4.5–7 mm long (pedicels are cylindrical and flowers 5.5–5 mm long in C. odorata var. botryoides). From C. rotundiflora it differs in the infrastaminal scales equalling or exceeding the corolla tube, cylindrical stamen filaments and styles, as well as stigmas 0.5–0.6 mm wide (in C. rotundiflora the scales are shorter than corolla tube, filaments and styles are subulate and stigmas 1–1.5 mm wide. From C. globiflora it differs in the spreading to reflexed corolla lobes and globose-depressed stigmas (in C. globiflora, corolla lobes are erect-connivent and stigmas conical).

Etymology: The specific epithet is a feminine adjective that comes from the name of the mountain range to which the species is apparently endemic. The word “Mantiqueira” is derived from Tupi-Guarani meaning “mountains that cry” alluding perhaps to the plethora of dripping water, streams and rivers that are present during the wet season with abundant rainfall (Mendes Júnior et al. 1991).


Vernacular names: The common names used in the area are: Cipó-chumbo, fios-de-ovos, erva-de-passarinho (although also commonly used for other species of Cuscuta that occur in the region).



Mihai Costea, Simone Soares da Silva, Rosangela Simao-Bianchini, Ana Rita G. Simoes and Sasa Stefanovic. 2021. Notes on the Systematics of Cuscuta sect. Subulatae (subg. Grammica) with the Description of Cuscuta mantiqueirana, A New Species from Brazil. PhytoKeys. 184: 27-44.  DOI: 10.3897/phytokeys.184.69037