Murdannia cryptantha (Commelinaceae), a New Species with Cleistogamous Flowers from Australia and Papua New Guinea

Abstract

Murdannia cryptantha (Commelinaceae), a new species from Australia and Papua New Guinea, is described. It is most closely related to M. graminea, and it is the first species of Murdannia reported to have cleistogamous flowers. The species of Murdannia Royle once were mostly included in the genus Aneilema R. Brown (Faden, 1978). Thus, when I attempted to determine the correct generic placement for all epithets in Aneilema, I also surveyed the species of Murdannia (Faden, 1991). In the course of that investigation I came upon slender plants of a Murdannia species from northern Queensland, Australia, that generally resembled the widespread species M. graminea (R. Brown) G. Brueckner except for the presence of sessile, axillary flowers and capsules, in addition to terminal inflorescences and infructescences. It was not until I obtained living material (A. Faden 2/91) that I was able to confirm that such plants represent a distinct species. Murdannia cryptantha Faden, sp. nov. TYPE: Australia. Queensland. Port Curtis Dist.: road from Rockhampton to Emerald, 3 km beyond Gogango, fenced area across railway line, brigalow bushed-grassland with frequent small temporary water holes, edge of temporary pools, 3 Mar. 1991, A. J. Faden 2/91 (holotype, US; isotypes, K, BRI). Figures 1-2. Herba perennis foliis omnibus caulinibus 1.5-7(-13) cm longis, 1.5-5.5 mm latis, thyrso terminali et floribus axillaribus sessilibus vel subsessilibus cleistogamis, capsulis (5-)6-10(-12) mm longis, ca. 2 mm crassis, loculis (4-)68(-15)-seminalibus, seminibus 0.6-0.9(-1.1) mm latis. Perennial with thickened, sometimes fusiform roots to 3 mm thick. Shoots erect to ascending, often rooting at the lower nodes, to ca. 35 cm long, unbranched or sparsely branched basally. Internodes 2-7 cm long, glabrous to pubescent, sometimes the pubescence confined to a longitudinal line. Leaves all cauline, distichous or in an open spiral; sheaths 0.5-2 cm long, often splitting to the base, c li te or ciliolate at the apex and along the fused edge, sheath surface glabrous or pubescent; lamina sessile, linear-lanceolate, decreasing in length distally on the flowering shoot, conduplicate or planar, often recurved at the apex, 1.5-7(-13) cm long, 1.5-5.5 mm wide, with base rounded to somewhat amplexicaul and apex acuminate to acute, margins undulate or planar, ciliate or ciliolate at the base of the lamina, sometimes scabrid at the apex, otherwise glabrous, both surfaces of the lamina glabrous to sparsely pubescent, sometimes only the abaxial surface pubescent. Inflorescences axillary and terminal, glabrous, the axi ary enclosed within a leaf sheath and consisting of a single sessile, bracteolate cincinnus that produces 1-4 sessile or subsessile cleistogamous flowers, the terminal inflorescence a lax thyrse consisting of 1-4 cincinni, each cincinnus to 4 cm long and producing up to 8 chasmogamous flowers. Bracts of the cincinni of the terminal inflorescences linear to ovate-lanceolate, 1-9 mm long; bracteoles of the terminal inflorescences ovate to lanceolate-elliptic, 0.7-2.5 mm long. Flowers all bisexual or an occasional chasmogamous one staminate. Chasmogamous flowers slightly zygomorphic; pedicels erect, 4-8.5 mm long in flower, to 9 mm long in fruit, glabrous. Sepals subequal, boat-shaped, elliptic to oblong-elliptic, 3-7 mm long in flower, to 8 mm long in fruit, glabrous. Petals subequal, not clawed, ovate to suborbicular, 5-9 mm long, pale purple to mauve or lavender, glabrous. Filaments of stamens and staminodes free. Stamens antesepalous, equal but all bending to one side of the flower, filaments bending outwards near the middle, 2.5-4 mm long, densely bearded with moniliform hairs below the middle, anthers dorsifixed, elliptic or oblong-elliptic, 1-2 mm long. Stami odes antepetalous, symmetrically arranged, filaments shorter and more slender than those of the stamens, densely bearded below the middle, antherodes basifixed, 0.5-0.7 mm long, usually ovate with a cordate base, yellow. Ovary sessile, trigonous, 2-2.5 mm long, trilocular, glabrous, locules up to 13-ovulate, ovules uniseriate, style bent away from NOVON 3: 133-136. 1993. This content downloaded from 157.55.39.27 on Mon, 05 Sep 2016 06:07:31 UTC All use subject to http://about.jstor.org/terms