569 



intermediis prominulis medianis parcius aculeatis, utroque 

 jugo int^rmedio in alam divaricatam lanceolatam uncinato- 

 ciliolatam 3-5 mm. longam ad apicem desinente (alls eas 

 pedium Mercurii simulantibus), jugis marginalibus prominulis, 

 vittis nullis, carpophoro obsolescente setaceo uno mericarpio 

 adnato et cum eo deciduo, foliis palmatipartitis petiolatis, 

 petiolo basin versus subdilatato pilis longis ciliato ad basin. 

 ipsam fimbriate sed non rrbe stipulate. 



Uldinia mercurialis n. sp. (Tab. xxxvii.). Herba 

 annua, caulibus prostratis rigidis plerisque simplicibus glabris, 

 foliis radicalibus longe petiolatis, lamina ambitu sub- 

 orbiculari-cordata 10-15 mm. longa parcissime pilosa tri- 

 partita, segmentis ovato-cuneatis obtuse trifidis vel lobato- 

 incisis, petiolo 10-30 mm. longo, foliis caulinis valde minoribus 

 plerisque oppositis, umbellis 4-floris, pedunculis robustis 

 5-7 mm. longis axillaribus, petalis caeruleis 1 mm. longis, 

 involucri bracteis 4 lanceolatis ciliatis circiter 3 mm. longis, 

 mericarpiis minute papillosis 4 mm. longis vix 2 mm. latis 

 minus quam 1 mm. crassis, alis divaricatis 2-4 mm, longis. 



This curious little plant, collected by Mr. E. H. Ising 

 along the railway line at Ooldea in September, 1920, does not 

 seem to fit into any of the existing genera of the tribe 

 Hydrwotyleae. It has the habit of Didiscus, but differs in 

 the absence of a free persistent carpophore. In the somewhat 

 dilated and ciliate base of the petiole it resembles D. glanci- 

 folius. The carpophore of Uldinia is setaceous and adnate to 

 the slightly grooved face of the narrow commissure of one of 

 the two niericai-ps. It is fragile at base and falls off with the 

 mericaip to which it is attached. From Hydrocotyle it differs 

 in the deeply-cut leaves, the absence of stipules, the imbricate 

 petals, and the dry station; from TracJiymene, DC, in the 

 absence of a free persistent carpophore, in the petals not 

 inflexed, in the simple umbels and the dilated base of the 

 petiole; from Centefia in the lesser number of ribs on the 

 mericarp and the divided leaves. As regards the two new 

 Australian genera created by Domin in 1908 (in Beihefte 

 ium Botan. Centralblait, xxiii., Abt. ii., 291-4), it differs 

 from Xeoseiadivm in the flattened fruit, deeply-cut leaves, 

 and in the absence of free stipules. (N. glochidiatum, 

 J)oiiL.=Hydjocotyle glochidiata ^ Benth. ; Gentella glochidiata^ 

 Drude.) From the other new genus, Homed osciadium, it 

 differs in the adnate deciduous carpophore, and from both 

 of these genera in the few-flowered umbels. (H. verticillatum, 

 T)om..= Hydrocotyle verticUlata, Turcz. ; Centella hom<ila- 

 carpa, Drude.) The hooked prickles or bristles which stand 

 R 



