Zyzyura H. Rob. & Pruski, 2013

Robinson, Harold & Pruski, John F., 2013, Zyzyura, a new genus of Eupatorieae (Asteraceae) from Belize, PhytoKeys 20, pp. 1-7 : 3-5

Zyzyura H. Rob. & Pruski gen nov.

Differs from Fleischmannia by the conical and fistulose receptacle, the eximbricate rather ‘Piquerian’ involucre, the slender-based corolla with broadly campanulate limb, and elongate cells of the carpopodium.

Type.

Fleischmannia mayana Pruski.

Description.

Decumbent epilithic herbs rooting at proximal nodes, prostrate portions 5-20 cm long, with short internodes, mostly glabrous, ascending portions 15-30 cm tall, with few small hairs, with long basal internodes; stems narrowly fistulose. Leaves ( Fig. 1A ) opposite, petioles mostly 3-5 mm; blades deltate in outline, mostly 4-7 mm long and wide, 3-7-lobed with sinuses 1/3-1/2 to midvein, basal margin truncate or subtruncate, triplinervate at base, margins of lobes often slightly notched, sparsely pilose adaxially, paler and hairless with crowded glandular dots abaxially. Inflorescence ( Fig. 1B ) terminal on ascending portions, ascending parts not branched below, distally loosely branching with 3-10 capitula, with few minute opposite to subopposite bracteoles; peduncles mostly 0.5-1.8 cm long. Capitula discoid, broadly hemispherical, to 7 mm high and wide; involucres ( Fig. 1C ) eximbricate; bracts c. 16 in mostly 2 series, subequal, obovate, with obtuse to rounded tips, chartaceous-becoming more scarious distally, bicostate proximally, few shorter outer bracts, scarcely spreading at maturity, essentially glabrous; receptacle ( Fig. 1C ) high-conical, fistulose, epaleate, without evidence of fully developed florets born on distal part. Florets 20-23; corollas white, 2.2-2.3 mm long, mostly glabrous, sparse glandular dots on lobes, immediate base dilated, thickly ribbed, narrowed to a slender tube closely investing the style, limb abruptly ampliate, campanulate, lobes ( Fig. 1D ) deltate, with intermarginal ribs, cells projecting at distal ends on inner and outer surface; anther collars slender, with numerous annular thickenings that do not completely obscure transverse cell walls; anther thecae ( Fig. 1E ) c. 0.5 mm long; apical appendage slightly broader than long. Style base without expanded node, papillae or hairs, style appendages thickened, densely papillose. Cypsela ( Fig. 2 ) 1.2-1.3 mm long, somewhat fusiform, 3-5 costate, with few scabrae on ribs; carpopodium ( Fig. 1F ) broadened, with distinct projecting upper rim, cells enlarged and elongate with moderately thickened walls; pappus iniser ate ( Fig. 2 ) with c. 10 persistent capillary bristles, reaching to approximately the base of corolla lobes, broadened but not contiguous at base, scabridulous, narrowed to apex. Pollen c. 18 μm in diam. in fluid.

Distribution.

The genus contains only the single species that may be endemic to the type locality in the Maya Mountains of the Cockscomb range in Belize.

Ecology.

Cited as epilithic.

Etymology.

Contrived name (no meaning).

Specimens examined.

Zyzyura mayana (Pruski) H. Rob. & Pruski, comb. nov. (IPNI ID: urn:lsid:ipni.org:names:77124264-1), basionym: Fleischmannia mayana Pruski in Pruski and Clase, Phytoneuron 2012-32: 6. 2012. Presently known only from Victoria Peak in the Cockscomb range of the Maya Mountains in Belize (Brewer & Pau 3349, holotype MO).

Figures

Figure 1. Zyzyura mayana (Pruski) H. Rob. & Pruski, A Prostrate portion of living plants showing lobed leaves B Capitula on erect flowering branches of living plant showing denser floral material near centers of capitula C Capitula of pressed specimen, lower capitulum showing eximbricate involucral bracts, upper head split, showing conical fistulose receptacle, upper capitulum also showing loose corolla D SEM of corolla lobes showing surfaces with protruding cells E Anther showing short theca and broad apical appendage F SEM micrograph of carpopodium showing elongate cells. (All from Brewer & Pau 3349)

Figure 2. Zyzyura mayana, cypsela showing pappus of c. 10 non-contiguous bristles. (From Brewer & Pau 3349)