Cuscuta mantiqueirana Costea, S.S.Silva, Sim.-Bianch., 2021

Costea, Mihai, Silva, Simone Soares da, Simao-Bianchini, Rosangela, Simoes, Ana Rita G. & Stefanovic, Sasa, 2021, Notes on the systematics of Cuscuta sect. Subulatae (subg. Grammica) with the description of Cuscuta mantiqueirana, a new species from Brazil, PhytoKeys 184, pp. 27-44 : 27

Cuscuta mantiqueirana Costea, S.S.Silva, Sim.-Bianch. sp. nov.

Figs 2 , 3 , 4

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).

Type.

Brazil. Minas Gerais: Camanducaia, Monte Verde. Parasita com ramos desde alaranjados até vináceos, sempre em local sombreado e humido . Flores amarelas, 22 IV 1999, R. Simão-Bianchini 1241 (holotype: SP!; isotypes: K!, NY!, MBM!, R!, SPF!, UB n.v., UEC!, WLU!)

Description.

Stems medium to coarse, yellow-orange, purple-tinged or entirely purple. Inflorescences paniculiform-racemiform, occasionally glomerulate, usually not confluent; pedicels 1.5-4 mm, thick, gradually tapering into the fleshy, conical receptacle; bracts 1 at the base of cymes, 1.1-2.5 mm long and 0.8-1.6 mm wide, fleshy, triangular-ovate, rounded, not carinate, margins entire. Flowers 5-merous, (4-) 5-7 mm long, fleshy, white when fresh, dark-brown when dried; papillae absent; laticifers ± visible, translucent in the calyx, corolla lobes, and more noticeable, dark-colored in the 1/3 distal half of the ovary; isolated, oblong-ovoid. A few stomata are present along the calyx mid-vein lobes, but stomatiferous carinas are usually absent; calyx 2.8-4 mm long, creamy-white to purple-tinged when fresh, dark-brown when dried, not reticulate, dull, cupulate, ca. 3/4 as long as corolla tube, divided 2/3-4/5 to the base, tube 0.5-1.5 mm long, lobes 2-2.5 mm long, ovate-oblong, longer than wide to as long as wide, the two external ones overlapping, usually not carinate, margins membranous, finely erose, not auriculate at base, apex rounded; corolla (4-) 4.5-7 mm long, tube 2.1-4.6 mm long, campanulate but becoming ± globose at fructification; lobes 1.8-2.5 mm long, initially erect, later reflexed, shorter than the tube, broadly ovate, overlapping, ± auriculate at base, margin entire to irregularly crenulate, apex rounded, straight; stamens exserted, shorter than the corolla lobes, anthers 0.8-1.2 mm long, elliptic to oblong, filaments 0.6-0.8 mm long; pollen 3-zonocolpate,19-29.5 μm long and 17-20 μm wide, subprolate to spheroidal or suboblate, tectum microreticulate to reticulate, lumina 0.9-3.3 μm in diameter; infrastaminal scales 3-5 mm long, equalling to slightly longer than corolla tube, ovate to oblong, bridged at 0.7-1.6 mm, densely fimbriatae, fimbriae 50-80, 0.5-1.2 mm long, thin-filiform without papillae distally; ovary apex on both sides of styles raised to form two pairs of lobes or projections with stomata, 0.4-0.6 mm long; styles 0.3-0.9 mm long, 0.3-0.5 mm thick, much shorter than the ovary, cylindrical to slightly subulate, sometimes also with stomata at their base; stigma 0.35-0.6 mm long and 0.5-0.7 mm wide, white to purple in the fresh flowers, globose to wider than long, convoluted and lobed. Capsules circumscissile, 4-4.8 mm long and 4-5.5 wide mm, globose to ovoid, with a collar around the large interstylar aperture, opaque, entirely surrounded by the withered, persistent corolla. Seeds 2 per capsule, 1.5-2.8 mm long and 2-2.4 mm wide, dorsiventrally compressed, subrotund, hilum area lateral, 0.7-1 mm in diameter, scar 0.25-0.30 mm long, seed coat alveolate/papillate. Chromosome number not known.

Geographical distribution and ecology.

The new species is apparently endemic to Serra da Mantiqueira in Southeastern Brazil (states of Minas Gerais, Rio de Janeiro and São Paulo), where it occurs at elevations between 800-2360 m. The climate is mesothermic, characterized by distinct dry and rainy seasons, with an average temperature that depends on the elevation, but generally exceeding 10 °C ( ICMBio 2018). Serra da Mantiqueira is part of the Atlantic Forest Biome and the habitat of C. mantiqueirana consists of montane and upper montane cloud forests ( Segadas-Vianna and Dau 1965; Ururahy et al. 1983; Veloso et al. 2012). During field work conducted in Itatiaia National Park and Monte Verde, we observed C. mantiqueirana at forest edges, margins of roads and clearings as well as parasitizing isolated woody plants in the forest (Fig. 4A, B ). The most common host is Fuchsia regia (Vell.) Munz ( Onagraceae ; Fig. 4E ), which is the most widely distributed species of this genus in Brazil, occurring throughout the distribution range of C. mantiqueirana ( Berry 1989). Fuchsia regia is currently accepted to include three subspecies, Fuchsia regia , serrae P. Berry, and reitzii P. Berry ( Berry 1989), and future field work will have to determine the frequency of occurrence on these subspecies. To a less extent, perhaps as secondary hosts, C. mantiqueirana parasitizes other herbaceous or woody plants: Asteraceae ( Baccharis L., Lepidaploa (Cass.) Cass., Mikania Willd., including Mikania micrantha Kunth, and other unidentified Asteraceae ), Euphorbiaceae ( Croton L.), Fabaceae , Melastomatacaeae, Primulaceae ( Myrsine venosa A. DC.), Polygonaceae (unidentified), Rubiaceae (cf. Cuscuta Spermacoce L.), Solanaceae ( Solanum L.), and Styracaceae .

Phenology.

Flowering in Nov-Dec and Feb-Aug, which may depend on the elevation. Very few herbarium specimens possess capsules and seeds which suggests that plants are preponderantly xenogamous and also reproducing vegetatively ( Wright et al. 2012).

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).

Provisional conservation status.

The GeoCAT rapid assessment tool ( Bachman et al. 2011) assigned an Endangered (EN) conservation status based on an EOO of 33011.111 Km2 and a Vulnerable (VU) status based an AOO of 504.000 Km2. Further field research is necessary to investigate possible additional distributional records in the region, and assess other factors such as habitat threats to determine if this species is in need of conservation in any of the parts of the extensive Mantiqueira mountain range.

Additional specimens examined.

Brazil. Rio de Janeiro: Itatiaia, 13 Apr 1963, E. Pereira & C. Pereira 7559 (HB); idem, Km 7 da estrada de Registro para Planalto, 17 Feb 1969, G.F.J. Pabst 9306 (MBM, HB); Parque Nacional de Itatiaia , 2 Nov 1965, G.G. Eiten & L.T. Eiten 6528 (SP); idem, 2 Apr 1960, O.M. Barth 7144 (IOC, US); idem Pico das Agulhas Negras, 2159 m, 1 May 1977, D.M. Vital s.n. (UEC, BR, NY); idem, Estrada Nova Km 8, 25 Mar 1942, A.C. Brade 17266 (RB); idem, 2200 m, 1 May 1977, J. Vasconcellos-Neto et al. s.n. (UEC); Estrada do Ponto Zero para as prateleiras, 22°22'12"S, 44°42'31"W, 2380 m, 11 Dec 2002, R. Marquete et al. 3437 (RB; DNA accession 1123); Resende , West side of Mt. Itaiaia , at km 9-10 km on road from “Registro” to the shelter house, "Abrigo Rebouças”, 2100 m, 7 Nov 1965, G.G. Eiten & L.T. Eiten 6682 (K, SP, NY, MO, UBC, US); Estrada vicinal de acesso ao Pico das Agulhas Negras, 24 May 1996, G.F. Árbocz 2750 et al. (SP, NY, UEC, WLU). Minas Gerais : Alto Caparao , Parque Nacional do Caparao , Trilha Tronqueira ao Pico da Bandeira , 13 Mar 2010, J.M. Silva & J. Cordeiro 7543 (MBM); Camanducaia , Monte Verde ; idem, 3 Jun 1992, R. Simão-Bianchini 317 (SPF, WLU); idem, 12 Jan 2020, R. Simão-Bianchini 2332 (SP); idem, 16 Mar 1976, H.F. Leitão Filho et al. 1815 (UEC, SPSF, UB, WLU) idem, Serra da Mantiqueira , 11 Dec 2001, L.D. Meireles & R. Balinello 770 (UEC); idem, Pico do Selado , 1810 m, 17 May 2002, L.S. Kinoshita et al. 72 (UEC); Itamonte , Parque Nacional do Itatiaia , 20 Nov 2018, S.S. Silva et al. Itati 02, 04, 05 (SP, WLU); idem, 21 Nov 2018, S.S. Silva et al. Itati 08 (SP, WLU; DNA accession 2436); idem, Itamonte , Serra Fina , Sitio Pierre , 2100 m, 20 Jul 2005, L.D. Meireles et al. 1843 (SP, UEC); Idem , 4 Apr 1995, 2100 m, I. Koch & L.S. Kinoshita 449 (UEC); Sao Paulo : Campos do Jordao , Instituto Kurihara , 8 Jun 1940, G. Hashimoto 262 (SP); idem, Parque Estadual Campos do Jordão, 1760 m, 8 Feb 1980, R.A.A. Barreto 48 (SPSF); idem, Praia São José dos Alpes, 8 Jun 1992, E. Gianotti et al. 26667 (UEC); idem, 2 Aug 1980, A.A.B. Rubens 48 (RB) Pindamonhangaba, P.E. de Campos do Jordão, 12 Apr 1985, M.J. Robim 277 (SPSF); idem, 12 Apr 1985, C. Proença & M.F. Bean 496 (CEN, UB) .

Figures

Figure 2. Comparative morphology of Cuscuta mantiqueirana and C. odorata var. botryoides using rehydrated herbarium material A-M Cuscuta mantiqueirana A inflorescence B incipient stage of inflorescence development showing bract and developing flowers C flower and bract D calyx 3 D, note the receptacle prolonging into obconical pedicel E, F calyx dissected, variation G corolla 3 D H corolla dissected to show infrastaminal scales and stamens I stoma on calyx lobe, note that large protuberances with stomata do not develop in this species J distal part of infrastaminal scale K detail of infrastaminal scale fimbriae, note that no papillae are present L gynoecium M detail of distal part of ovary showing 4 lobes with stomata flanking the two styles. All images were obtained from G. F. Arbocz et al. 2750 except A, B, H and L which are from the type, Simao-Bianchini 1241 N-W Cuscuta odorata var. botryoides N flower O calyces 3 D P calyx dissected, note the broader calyx lobes, two of them with prominent carinas that bear stomata (indicated by arrows) R detail of carinate calyx lobe S corolla 3 D T fragment of dissected corolla U infrastaminal scales V detail of fimbriae showing 1 - 2 papillae at their tips (arrows) W 1 gynoecium W 2 detail of distal part of ovary, note the absence of lobes with stomata. All images from Lobb 49 except P, R = Hatschbach 22109 and V = Hoehne s. n. Scale bars: 1 mm (A-H, L, N-Q, S-U, W 1, W 2); 50 μm (I); 0.5 mm (J, M, R, K); 0.25 mm (V).

Figure 3. Micromorphology of Cuscuta mantiqueirana and C. odorata var. botryoides A-G Cuscuta mantiqueirana A distal part of ovary B stomata on lobes flanking styles C stomata (indicated by arrows) at the base of styles D-E infrastaminal scale fimbriae and detail F-G 3 - colpate, reticulate pollen. All images from G. F. Arbocz et al. 2750 except C which is from Simao-Bianchini 1241 H-K Cuscuta odorata var. botryoides H gynoecium I-K pollen grain: 5 - colpate with perforate tectum. All images from Burkhart 1626. Scale bars: 0.5 mm (A); 100 μm (B-D); 50 μm (E); 10 μm (F, I); 1 mm (H); 5 μm (G, J, K).

Figure 4. 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).