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Record: oai:ARNO:525425

AuthorP. van Royen
TitleSome new Australasian species of Xyris
JournalBlumea - Biodiversity, Evolution and Biogeography of Plants
AbstractDuring the study of the Xyridaceae of the Malaysian area it was desirable to study those of Australia and Continental Asia as well. The Malaysian species now have, in the meantime, been published (Flora Malesiana, ser. 1, 4, 1953, 366—376). To the new taxa described in Blumea 7, 1953, 307—308 the Latin diagnoses of the following new species and a new section may here be added: 1. Xyris linifolia van Royen, nov. spec. — Fig. 1. Herba mediocris, ad 40 cm alta. Folia subulata, ad 25 cm longa, c. 1 cm diam., subfalcata, acuta, sparse papillata; vaginae 6—8 cm longae, basi 3—6 mm latae; ligula brevis acuta c. 1 mm longa. Scapus 20—40 cm, c. 1 mm diam., teretiusculus, 2- vel pluricostatus, minute papillatus. Capitula ovoidea ad globosa, pauciflora, ad 7 X 6 mm, bracteae basales suborbiculares, 4.5—5.5 X 3.5—4 mm, obtusae, enerves, in parte superiori minute papillatae, papillis arcum triangularem formantibus, medianae obovatae, 6—6.5 X 4.5—5 mm, nervosae, nervis nervo mediano et uno nervo completo in costae utroque latere orto ad bracteae apicem laxe reticulato compositis, in parte mediana superiori minute papillatae, papillis aream suborbicularem formantibus. Flores masculini ignoti, florum femineorum sepala lateralia angusta, 5.5—6.5 X c. 1.5 mm, acutiuscula, emarginata, ecristata, alata, alis sat latis, sepalum medianum cucullatum, 4.5—5 X c. 2 mm, binerve. Petala nondum evoluta limbo orbiculari 4 mm longo et lato munita, margine serrata, unguiculo c. 2 mm. Stamina c. 3 mm, antherae c. 2 mm, apice profunde emarginatae, basi apiceque obtusae thecis emarginatis. Staminodia 2.5—3 mm, penicillata bifida? Ovarium incomplete cognitum, stylus 4.5—5 mm (vel longior?), trifidus, ramificationibus c. 2.5 mm, apice capitatis. Capsula ignota. Typus: Smiles s. n. in K. Distr.: Siam — in open grassland near base of Mt Kau. This species differs from all Malaysian species except X. borneensis in the terete leaves and the three complete nerves of the bracts. Though the leaves of X. borneensis are also terete, the bracts are provided with numerous complete nerves. Moreover, the lateral sepals in X. borneensis are ciliate, those of X. linifolia smooth and entire. In its anthers the present species resembles X. ridleyi, X. pauciflora, X. borneensis, X. capensis, X. complanata etc., the anthers being deeply incised at the top and the thecae emarginate. 2. Xyris nigromucronata van Royen, nov. spec. — Fig. 2. Herba annua parva, ad 6 cm alta. Folia linearia, 1—2.5 cm X c. 1 mm, mucronata, apice nigra et pilis robustis paucis hispida, anguste bi-alata, alis tenuiter et sparse papillatis, in parte basali elliptica in sectione transversa, apice incrassata et triangularia in sectione transversa, vaginae 3— 6 cm longae, apice pilis multis albis munitae, margine membranacea, marginibus pedunculi basin includentibus, pedunculo ligula biloba pilis destituta praedito. Scapus ad 6 cm longus, subangularis, valde obscure alatus, alis 1 vel 2, proxime infra capitulum elatus ubi 3- vel 4-alatus. Capitula oblongo-ellipsoidea, c. 7 X 5 mm, bracteae omnes cristatae, basales ovatae, c. 6.5 X 3 mm, sat brunneo-nigrae, mucronatae, mucrone ad 2.5 mm longa, cristata, nigra, crista pallide flava in parte apicali tantum tenuiter et sparse papillata, medianae subcirculares ad panduriformes, 4—5 X 2—5 mm, margine sat brunneo-nigrae, uninerves, nervo completo laevi, in parte basali membranaceae. Sepala lateralia naviculata, fere ad apicem connata, c. 5 X 1 mm, membranacea ecristata. Petala 6, alba, 6—7 mm longa, unguiculata, ungui 4—5 mm, arcte cohaerentia et quasi tubulosa, limbo elliptico-oblongo, obtuso, c. 2 X 0.8 mm. Stamina 6, c. 1.2 mm, antheris ovoideis, c. 0.6 mm, truncatis, emarginatis thecae basi obtusae; filamenta subulata, c. 0.6 mm. Staminodia desunt. Ovarium subovoideum ad ellipsoideum, c. 2 X 1 mm, trilobum, in parte basali 3-, in parte superiori 1-loculare, stigmatibus 3 terminatum. Capsula ovario similis, sed ad 3 X 1.5 mm metiens; semina sparse papillatae. Typus: Pritzel 635 a in L. Distr.: Australia — in scrub between Moore and Murchinson river. This specimen was found mixed with Stylidium bulbiferum Benth. var. septentrionale Mild braed in Pritzel 635. Therefore it is separated from that species under 635 a. This highly characteristic species differs from all other species of Xyris by the fimbriate top of the sheath, the united lateral sepals (also found in the Brasilian X. obtusiuscula Nilsson), the 6 united petals, the 6 stamens (also once found by the author in X. bancana Miquel), the more or less campylotropous ovules, the entire style, and the papillate curved seeds. Moreover, the flowers seem to be white but owing to the dried material it can not be stated for certain whether this is the proper colour. These details warrant the establishment of a separate section in Xyris, Australoxyris with the following Latin diagnosis: Xyris Linnaeus, sect. Australoxyris van Royen, nov. sect. Folia apice in sectione transversa triangularia, vaginae exteriores apice ciliatae, flores capitati; sepala lateralia maxime connata; petala 6, connata; stamina 6; stylus simplex; ovarium in parte basali 3-loculare, in parte superiori 1-loculare; ovula plus minusve campylotropa; semina papillata. Typus: Xyris nigromucronata van Royen.
Document typearticle
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