Ceratolacis pedunculatum C. T. Philbrick, Novelo & Irgang, sp. nov. TYPE: Brazil. Minas Gerais: ca. 16 km SW of Pompeú, along BR- 262 on road to Martinhos Campos, rio Para, 19° 16' 36.9" S, 45° 07' 54.2" W, 598 m, 16 July 2001, C. T. Philbrick, A. Novelo R., B. E. Irgang & C. E de Senna Gastal 5679 (holotype, BHCB; isotypes, ICN, MEXU, M0, NY, WCSU).
Herba aquatica. Radices virides, elongatae et cylindricae ubi juvenes, ubi vetustiores latae thalloidesque. Folia petiolata, disticha, stipulata, ditheca, erecta, 1-6 plo divisa, raro subdichotoma vel pinnata; stipulae asymmetricae, ex folii base amplexicauli cymbiformi constatae. Inflorescentia uniflora, pedunculata. Flores solitarii in axillis foliaribus. Spathella claviformis. Pedunculus et pedicellus post spathellae rupturam elongantes. Tepala 3, uno in andropodii quoque latere, tertio tepalo ad andropodii apicem portato. Stamina 2. Andropodium et filamenta per anthesin elongantia. Pollinis grana in dyadibus. Ovarium ex 2 carpellis aequalibus compositum, 2-loculare, in pedicello oblique dispositum. Stigmata 2, libera, stigmatum base in fructu indurata, persistenti. Fructus capsularis, 2-locularis, apice emarginato, duabus valvis aequalibus, persisten- tibus, 3-costatis, marginibus suturalibus incrassatis. Pedunculus a pedicello in fructu non distinguibilis.
Aquatic herbs, perennial. Roots green, elongate and cylindrical when young, becoming broad and crust-like, irregular in outline when older, branched, prostrate, flattened to elliptical in cross section, median = 0.9 (0.3-5.2) mm [N = 50] wide, tightly attached to rocks via adhesive hairs, growing intertwined. Stems monomorphic, arising opposite or subopposite along the flanks of roots, 4.9 (0.9- 12) mm [N = 50] apart, obscured by leaf bases, erect, less than 0.1 mm high, unbranched. Leaves petiolate, distichous, stipulate, double-sheathed, upright, compound, 4 (1-6) [N = 50] times divided, rarely subdichotomous or pinnate, 17 (2.9-35.2) mm [N = 100] long, ultimate leaf segments linear to spatulate, 3.1 (0.2-9.5) mm [N = 100] long x 0.3 (0.1-1) mm [N = 100] wide, midvein faint or lacking, apices acute or obtuse; petiole 3.9 (0.4- 14) mm [N = 100] long, elliptical in cross section; stipules asymmetric, composed of an extension of the amplexicaul leaf base, 0.5 (0.1-5.6) mm [N = 50] long, larger on leaves subtending flowers, apex entire. Inflorescence with flowers pedunculate and solitary. Flowers 2 (1-6) [N = 50] per stem, hermaphroditic, zygomorphic, borne singly in a leaf axil, covered by a spathella, pedicellate; peduncle (below attachment point of spathella) 0.8 (0.1-3.1) mm [N = 100] long prior to spathella rupture, elongating to 2.6 (0.3-8.5) mm [N = 100] long after spathella rupture; spathella clavate, 2.4 (14.5) mm [N = 100] long x 1.1 (0.6-1.7) mm [N = 100] wide, rupturing apically, falling away completely in fruit; pedicels 0.8 (0.1-3.1) mm [N = 100] long prior to spathella rupture, elongating to 5.1 (1.8- 8.5) mm [N = 50] long after spathella rupture; tepals 3, scale-like, linear, acute, two (one on either side) at the base of the stalk from which the stamens arise (andropodium), 0.6 (0.2-1.8) mm [N = 50] long; a third tepal occurring at the apex of the andropodium, andropodial tepal 0.4 (0.3-0.5) mm [N = 50] long; stamens 2, deciduous; andropodium 1 (0.6-2) mm [N = 50] long prior to spathella rupture, during anthesis elongating to 4.3 (2-7) mm [N = 50] long; filaments 0.4 (0.2-1.8) mm [N = 50] long prior to spathella rupture, during anthesis elongating to 0.9 (0.4-1.8) mm [N = 50] long; anthers quadrangular, with parallel sides, 1.1 (0.7- 1.4) mm [N = 50] long, 1 (0.6-1.2) mm [N = 50] wide, dehiscing introrsely and longitudinally, inner and outer thecae of equal length; pollen in dyads, tricolpate, 35 (31 10) µm [N = 100] long, 24 (19- 28) µm [N = 100] wide; ovary with 2 equal carpels, 2-locular, oval in shape, oriented obliquely on the pedicel, 1.5 (0.7-2.6) mm [N = 50] long, 1 (0.6- 1.7) mm [N = 50] wide, with 6 longitudinal dark lines on the ovary wall; ovules 20 (12-32) [N = 25]; stigmas 2, free, each stigma triangular in outline, widest at base, upright prior to spathella rup- ture, 0.5 (0.3-1) mm [N = 50] long, during anthesis upright or divergent, elongating to 0.9 (0.4-1.1) mm [N = 50] long, base of stigmas becoming hardened and persisting in fruit. Fruit a 2-locular capsule, 1.8 (1.4-2.1) mm [N = 50] long, 1.3 (0.9-1.5) mm [N = 50] wide, capsule apex emarginate due to persistent stigma bases, with two equal valves, persistent, valves 3-ribbed, suture margins thickened and rib-like; peduncle not distinguishable from pedicel in capsule (due to shedding of spathella and parenchymatous tissues of peduncle and pedicel); length of peduncle and pedicel combined 6.8 (1.5-17) mm [N = 100] long. Mature seeds unknown.
Distribution. Ceratolacis pedunculatum is known from four locations in the central part of the state of Minas Gerais, Brazil (Fig. 2), ranging from about 500 to 650 m elevation. The related C. erythrolichen is known only from the type collection (rio Tocantins), which is approximately 1500 km north of the locations where C. pedunculatum was collected. A1though the type locality of C. erythrolichen was in the state of Goias at the time the species was described in 1849, the location is presently in the state of Tocantins.
Note: See Philbrick et al. (2004; Novon 14: 108-113) for discussion of how C. pedunculatum differs from C. erythrolichen. That latter is known only from the type collection.
Paratypes. BRAZIL. Minas Gerais: on road from Diamantina (Gouveia) to Curvelo, confluence of rio Parauna and rio Cipo, 9 July 2002 C. T. Philbrick, A. Novelo R., B. E. Irgang & C. V. de Senna Gastal 5649 (BHCB, ICN, MEXU, MO, WCSU); ca. 10 km W of Sao Sebastiao, Route BR-420, on road to Pompeu, 9 July 2001, C. T. Philbrick, A. Novelo R., B. E. Irgang & C. V de Senna Gastal 5651 (BHCB, ICN, MEXU, M0, WCSU), ca. 16 km SW of Pompeu, along BR-262 on road to Martinhos Campos, rio Para, 16 July 2001, C. E Philbrick, A. Novelo R., B. E. Irgang & C. V. de Senna Gastal 5678 (BHCB, ICN, MEXU, M0, NY, WCSU); 2 Aug. 2002, C. T. Philbrick & A. Novelo R. 5781 (BHCB, ICN, MEXU, M0, NY, WCSU); 30 km N of Corinto on BR-496, ca. 200 m up- stream of bridge, rio Bicudo, 28 July 2002, C. T. Philbrick & A. Novelo R. 5761 (BHCB, ICN, MEXU, M0, NY, WCSU).