39 Ptilotus humifusus, a new species ofAmaranthaceae from Queensland by G. Benl Abstract: Benl, G.: Ptilotus humifusus, anewspeciesofAmaranthaceae from Queensland. - Sendtnera 1: 39-44. 1993. ISSN 0944-0178. A new Ptilotus from Queensland, P. humifiisus Benl sp. nov., is described and figured with a photograph ofthe holotype and analytical drawings ofthe flower. Type specimens are cited and thenewtaxoniscomparedwithP.procumbensBenl, itsclosestcongener. Ptilotus humifusus Benl sp. nov. (Figs. 1 and 2) Herba annua pluricaulis mox procumbens. Caules usque ad 35 cm et ultra graciles caes- pitosi, e radice fusiformi Orientes, primo erecti dein patentes, (glauci-)virides, lineis pallidioribus partim rubescentibus angulati-striati, ad circa 20 cm longi, parce ramosi atque foliati; in statu juvenili pubescentes, puis albidis distincte nodulosis dense induti dein glabrescentes. Rami laterales divergentes, summi apicem caulis superantes, vetustiores pedunculos formantes et in rhachides spicarum transeuntes. Folia coriacea integerrima; radicalia plus minusve deficientia. Folia caulina altema ad circa 4,5 x 0,6 cm, basi petioliformi (sub)ses3ilia; lamina (lineari-) lanceolata vel anguste elliptica breviter aristata, primo utrimque villosa (pilis ut in caulibus) mox glabrata, nervo mediano subtus conspicue prominenti. Spicae confertiflorae solitariae, caules ramosque terminantes,juveniles corneae circiter 1 cm diametro, florentes apiculati-cylindraceae, in holotypo usque ad 2,7 cm longae; rhachis pilis nodulosis tomentosa. Flores breviter pedicellati ad 50 et ultra congesti, albidi-pilosi visu violacei-rosei denique pallescentes. Bracteae bracteolaeque hyalino-scariosae, glaberrimae, superstites, inaequales: bracteae ovati- lanceolatae; bracteolae maiores subcordati-orbiculares, perianthio arcte appressae. Perianthium 5-partitum circa 6 mm longum, primo (rigidi-)erectum demum tepalis divergentibus campanulati-patens, apicibus nudis tepalorum lucidum, ima basi extus hirsuta contractum. Perianthii segmenta libera, infeme distincte tricostata, supeme marginibus scariosislatelimbata,juveniliamanifestebicolorata: areolamedianaincrassatanervis lateralibus exacte circumscripta atropurpurea demum viridula; margines in apice confluentes laete purpureae ad (violacei-)roseae, post anthesin dilute stramineae. Tepala omnia in dorso villosi- plumosa - pubescentia apices vix attingente -, pilis strictis oblique erectis diversiformibus, in parte supera spinulosi-articulatis, in parte infera brevioribus obscure nodulosis; 2 exteriora linearia, apice truncato et erosi-denticulato, intus glabertima; 3 interiora lineari-subulata baud breviora at angustiora (sub)acuta (apice interdum leviter incurvato), intus infeme pilis crispis tenuiter articulatis inter se intricatis obsessa. Stamina 5 aequalia fertilia; filamenta ad circiter mm mm 2,3 longa ligulata, infeme sensim ad 0,2 dilatata, in cupulam humilem imae basi 40 perianthii tantum insidentem transeuntia; pseudostaminodia interjecta nulla; antherae ellipsoideae dilute flavae. Gynoecium omnino glabrum; ovarium subclavatum sessile, circa 1,2 mm longum; stylusindivisuslongiorgracilisrectusexcentricus; stigmacapitellatumpapillosum. Species nova ad Ptilotumprocumbentem Benl appropinquans, sed haec species ob spicas maturas conicas, bracteas fliscas pilosas, tepala in apice recurvata, ob 4 stamina tantum perfecta, cupulam staminalem nimis longam et stylum brevem a Ptiloto humifuso manifeste differt. Holotypus: WarregoRegion, 40 km S ofCunnamuUa, 145°44'E, 28°19'S, Qld, 29July 1983, P. E. Conrick1484(AD 98413311, phot. M; isotypi: AD, CANB, M). Mat-forming ephemeral herb (Fig. 1) of spreading habit to c. 40 cm across, closely pubescent in vegetative parts and outer floral organs when young. Up to about 35 shoots mm arising tuft-like fi^om a slendertap-root ofc. 5 in diameter, at first upright then sprawling mm to forma rosette and curved slightlyupwards at theirfloriferoustips; tenuous by c. 1 to 2 thick near ground-level, attaining lengths ofup to and over 20 cm when fully grown, greyish green turning glaucous-green, finely striate with paler (sporadically reddish-tinged) angular ribs, evenly clothed withawhiteindument ofstraight to slightly curved nodulous hairs 0,8-1,1 mm longlaterconfinedto apical portionsandleaf-axilsonly. The(semi-)prostrate stems simple or openly branched, sparsely leafy throughout. Branches up to 5 (6) per stem and to c. 12 cm long, divaricate or ascending, obtusely 4- to 6-angled and hairy like main stem. Apices of stems, branchesandbranchletsalways developingpeduncles and rachises ofinflorescences, but branchlets sparse in present material. Leaves offirm texture, entire; radical ones lanceolate, to c. 4,8 cm long and 0,4 (-0,6) cm broad, soon withering, hence inconspicuous or wanting in matureplants. Caulineleaves alternate, c. 10to 15 all alongstems and branches, (0,6-) 1-2,5 (- 3,0) cm apart, mostly narrower than basal leaves, 1,8-4,5 x 0,12-0,6 cm, often patent, some- times ascending from prostrate stems. Blade (narrowly to oblong-)lanceolate or narrow- elliptic, oftenreddishpointedwithasmall colourless aristaof0,8-1 mm, sessile or occasionally subsessile wath a shortly decurrent petiole, chartaceous to thickly coriaceous, deep to grey- green, later appearing slightly glaucescent on both surfaces, sometimes reddish-tinged on almostparallel margins, evenlypubescent (withhairs as for stemsbut less dense) on either side only when young, soon glabrescent except in axils, where dense tufts ofhairs appear when a new branchlet is sprouting; pale midvein distinctly raised beneath. Fluffy flower spikes numerous, about 30 to 50 per plant, always terminal and solitary, mostly borne upturned at apices ofprocumbent peduncles, densely flowered and compact for the whole length, initially cone-shaped, thenlengtheningto short-cylindricwith aconoidtop, attaining 2,7 cm long x 1,4 cm across when fully opened, whitish-pubescent before and after anthesis. Rachis finally elongate, reaching 1,5 to 2 cm, the woody axis to 0,8 mm in diameter near the middle, yellowish, slightly zigzag, lanate by a soft to fluffy white-woolly tomentum offine irregularly mm septate crispyhairs 0,8-1,5 long, extremelyinterwoven forthe most part, continued to the mm 0,4-0,5 long pedicels (these jointed above the bracteoles) and concealing basal part of flowers. The bisexual flowers pentamerous (Fig. 2 A), from c. 10 to over 50 per spike, conspicuousbybrilliantviolet-roseto purplishtepal ends in flowering stages. Subtendingbract and bracteoles inconspicuous but well-developed, membranous, translucent-shining, concave, the midrib more or less excurrent, about half as long as the perianth at maturity, entirely glabrous, rather persistent on the woolly rachis after the perianthfalls, unequal in shape. Bract (Fig. 2 B) narrowly ovateto ovate-lanceolate, acuminatewith atop c. 0,2 mm long, becoming 2,2-3,0 mm, up to 1,4 mm broad below the middle, the light to dark brown midrib forming an obvious keel, the margins finely serrulate towards or near apex. The two bracteoles (Fig. 2 C) papery and colouriess, roundish obovate to subcordate-orbicular, becoming 2,8-3,5 mm long mm by (2,3-) 2,5-2,8 broad at or abovethe middle, the midrib weak, scarcely cuspidate with a 41 minute point, evidently serrulate to dentate in about the upper third of margins, completely mm embracing the perianth in its lowest part. Perianth scarcely exceeding 6 long, at first stiffly mm erect, later campanulately divergent to 2-4 across in upper scarious portion, copiously mm plumose externally, thickened and indurate towards a rounded base of0,8-1,2 diameter, formed by the constricted lowermost parts of tepals; base concave beneath due to sunken attachment of the pedicel, the notch densely surrounded by a ring of bristle-like nodulose hairiets 0,4-0,8 mm long. Tepals (Fig. 2 A) usually subequal, evidently bicolorous when flourishing, dull-purplish turning greenish, exhibiting a coriaceous dorsally pilose central areole, thistapering distally, borderedbymembranousglabrouspurpletoviolet-rose (later pale pinkish to stramineous), entire margins gradually dilated and fused apically at the lustrous tip; all perianth-segments three-ribbed in about lower halfto two-thirds, the prominent midvein continued to summit, the lateral nerves edging the opaque centre and convergent distally. Tepals free down to an open disk-like base, not bipartite (clawed), their dorsal white heterogeneous vestiture scarcely masking tepal colours. Hairs on tepals knotted (several- celled) straight comparatively thin, oftwo distinct kinds, unequal in length and structure: (a) feathery erecto-patent trichomes in about the distal halves to two-thirds of tepal minutely spinulose-articulate, (1,8-) 2,5-3,2 mm long and never exceeding the apex, in proximal part of tepals intermingled with orgivingwayto (b) much shorter, indistinctly and remotely nodulose hairiets about 0,4-1,0 mm long, more or less evanescent v^th age and ultimately leaving a convex subglabrous spot near base; the scarious marginal zones vanishing basally, enlarging upwards and fusing into the apical glabrous portion attaining 2 mm long in the two outer mm mm perianth-segments. These rather uniformely linear, becoming up to 6,2 long and c. 1 wide at orbelow middle, hardlycontracted (sometimes even widened) to atruncate irregularly erose-denticulate apex, reminiscent in this respect ofPtilotussymonii (Benl 1968, Fig. 1 b) or ofP. barkeri (Benl 1989, Fig. 1 D); inner faces completely glabrous. The three inner tepals Unear-subulate, their length and breadth averaging in the ratio 1 to 0,1 (-0,13), distinctly narrowed to an acute or subacute slightly toothed and sometimes inwardly curved tip; two or mostly three segments beset inside with strongly beard-like wool covering the lower region, the crisped hairs copiously borne marginally on one or both sides, thickish, weakly and irregularly septate, averaging 1,2 mm long, surrounding androecium and gynoecium. Distinct internal pubescence occasionally produced in two tepals only, then the outermost segment shaped much like an outer tepal, thus displaying a more or less intermediate character. Androecium and gynoecium (Fig. 2 D) markedly shorter than the perianth. The consistently pentamerous androecium with equally perfect stamens in all flowers examined; filaments mm mm upright, diaphanous and flattened, (1,8-) 2,0-2,3 (-2,5) long, to c. 0,08 broad near mm middle, somewhat tapering at top, gradually widening downwards to c. 0,2 and connate with broad sinuses into a short (c. 0,25 mm) staminal cupule without a free ring or nearly so, adherent to the perianth-base; intervening scale-like teeth or lobes (pseudostaminodes) absent; anthers ellipsoidal, about 0,45 x 0,22 mm, pale yellow in fertile stamens. Gynoecium entirely mm hairless; ovary obovoid to subclavate, almost sessile when fully developed, 0,8-1,5 long mm and up to 0,8 in largest diameter; style undivided, obviously eccentric, straight, 1,5-2,0 mm long on mature ovary, thickened at base to 0,2 mm, persistent; stigma more or less level withtheanthers, capitellate-papillose, ratherinconspicuouswhendried. Distribution: Up to the present known only from the type collection with limited range in the Warrego Region (South-west Queensland) where, following the collector's label, it was found growing in a large population ("frequent") 40 km south of Cunnamulla, forming mats in Eucalyptus woodland onsandyloamground. 42 The newly established species - observed in a very restricted site - should be regarded as endemic, "Rare" and coded "1RQ38" according to BRIGGS & LEIGH, 1988, unless material frombeyondthetype areashouldbecomeavailable. Etymology: NamedfromtheLatinhumifiisus, referringtothehabit spread out overtheground. Affinity: The present taxon shows resemblance to the endemic Ptilotusprocumbens (Benl 1983, Fig. 1) from Western Australia as regards the mat-forming habit; however, there is a considerable number ofwell pronounced differences primarily with respect to floral features, justifying specific rank for our novelty. In P. procumbens, bract and bracteoles are ovate- lanceolate, brownish and pilose, in contrast toP. humtfususwhere the bracteoles are roundish and all floral bracts are almost uncoloured and completely lacking indumentum. The tepals of P. procumbensbear recurved appendage-like apices, and merely four stamens are consistently functional, whereas inP. humifususthe perianth-segments have straight tips, and five stamens are fertile. P. procumbens is noteworthy for its short free filaments (0,6 mm) united to an unusually elongated staminal tube (1,3 mm), its stalked ovary being much longer than the sub- central style (s. Benl 1983, Fig. 2 H); inP. humifiisus 2,3 mm long filaments are fused to a verylow (0,25 mm) staminal cupule, andthe sessileovaryhasalongeccentrical style. From the material seen (comprising specimens measuring between c. 15 and 40 cm across) Ptilotus humifiisus would appear to be very constant in its features and in its distinctive appearance not comparable with any previously described species within the genus, except P. procumbenswithwhichacloserrelationship isclearlyevident. P. humifusushasto be inserted in Group VII (Annual herbs usually prostrateto ascending) ofourforthcomingrecord invol. 5 of"FloraofAustralia". Acknowledgements I am muchindebted to Dr. C. DennisAdams, London, for looking through the manuscript and suggesting valuable improvements. Grateful thanks are due to Mr. A. BÖHM and Mr. K. Ledlforpreparingtheillustrations. References Benl, G., 1958: Beitrag zu einer Revision der Gattung Ptilotus R. Br. (Amaranthaceae). - Mitt. Bot. Staatssamml. München2: 401-409. - 1968: Anew species ofPtilotus from South Australia (Amaranthaceae). - Trans. Roy. Soc. S. A. (Adelaide) 92: 33-36. - 1983: Taxonomic studies on Ptilotus R. Br. (Amaranthaceae) in Western Australia. - Nuytsia(Perth) 4: 263-274. - 1989: Ptilotus barkeri, a new species of Amaranthaceae from Lake Eyre Region, South Australia. -J. AdelaideBot. Gard. 11: 195-199. & Briggs, J. D. J. H. Leigh, 1988: RareorThreatened AustralianPlants. - Special Publication No. 14, AustralianNationalParksandWildlife Service, Canberra, pp. 277. Adress ofthe author: Dr. G. BENL, Botanische Staatssammlung München, Menzingerstraße 67, D- 80638 München 43 Figure 1. PtilotushumißisusBevl. Holotype sheet, AD 98413311. (PhotographK. Ledl). 44 Figure2. PtilotushumifitsusBenl. ~ A: Perianth spread open, outerview. B: Bract, innerface. C: Bracteole, innerface. D: Androeciumand Gynoecium. (Drawnfromholotypeby A. Böhm).