Ravenelia piepenbringiae Ebinghaus & Begerow, sp. nov. on Senegalia hayesii (Benth.) Britton & Rose (Mimosoideae, Leguminosae)

Ebinghaus, M. & Begerow, D., 2018, Raveneliapiepenbringiae and Raveneliahernandezii, two new rust species on Senegalia (Fabaceae, Mimosoideae) from Panama and Costa Rica, MycoKeys 41, pp. 51-63 : 52-53

Ravenelia piepenbringiae Ebinghaus & Begerow, sp. nov. on Senegalia hayesii (Benth.) Britton & Rose (Mimosoideae, Leguminosae) Fig. 2

Type.

Panama, Chiriquí Province, Dolega District, Los Algarrobos, Casa de la Alemana, Bosquecito, approx. 150 m a.s.l., 8°29'45.31"N, 82°25'56.24"W on Senegalia hayesii (Benth.) Britton and Rose, 17 February 2013, coll. M. Piepenbring MP 5157 [holotype: s.n. (PMA), isotypes: KR-M-0043654 (KR). M-0141345 (M)]

Etymology.

Named after M. Piepenbring, who discovered the rust fungus in her garden and provided the specimens.

Spermogonia and aecia not seen. Uredinia hypophyllous, single or in irregular groups, light brown, often associated with necrotic spots that are also evident on the adaxial surface, 0.1-0.8 mm in diameter, aparaphysate, subepidermal, covered by the epidermis when young, later erumpent. Urediniospores obovoidal, ellipsoidal or slightly curved, often limoniform with an acuminate apex, ochraceous brown, (18)21-25(29) × 12-15(20) mm; spore wall laterally 1-1.5 mm thick, apically and basally often slightly thickened, distinctly verrucose to echinulate; aculei 1.0-1.5 mm high, distances between aculei about 2 mm, germ pores 4-7, in equatorial position. Telia replacing uredinia or developing independently from uredinia, chestnut to dark brown, sometimes confluent. Teliospores roundish to broadly ellipsoidal to oblong in planar view, hemispherical in lateral view, with 4-6 probasidial cells across, single-layered, each teliospore formed by 9-13 probasidial cells, (44)58-73(78) mm in diameter, single probasidial cells (19)22-26(31) × (11)17-22(28) mm; cell wall thickened at the surface of the teliospore (epispore), 2-4(5) mm thick, often with a thin and hyaline outer layer, each probasidial cell with 7-11 rod-shaped, straight spines that are (1)2-3(4.5) mm long; cysts at the basis of the teliospores, uniseriate and in the same position and number as the peripheral probasidial cells, globose, hyaline, swelling in water, slightly swelling in lactophenol.

Further specimens. Type locality, 22 January 2014, M. Piepenbring 5203 [M-0141344 (M), s.n. (UCH)]. Type locality, 12 January 2017, M. Piepenbring & I. D. Quiroz González 5333 (UCH, s.n.).