ttydrocotyle.] XXXIV. UMBELLIFEEAE . 187 



1. HYDROCOTYLE, Linn. 



Calyx-teeth inconspicuous. Petals entire, valvate or rarely imbricate. 

 Fruits without vittae, orbicular or suborbicular, flattened laterally. Mericarps 

 placed edge to edge, usually with a prominent rib, rarely 2 or 3 on each face. 

 Seed straight, laterally compressed. Herbs, with slender creeping prostrate 

 stems often matted and rooting at the nodes, orbicular or renjform solitary 

 or fascicled minutely stipulate leaves, and simple umbels of small involucrate 

 hermaphrodite or rarely unisexual flowers. 



Spbcies, about 80, generally distributed througb the temperate and tropical regions. Of the 

 New Zealand species, one is distributed through Asia, Africa, North and South America, and 

 Australia, another extends to North and South America but not to Australia, while two are 

 restricted to New Zealand and Australia; the others are endemic. 



Etym. Prom the Greek, signifying water and a flat cup, in allusion to the cup-shaped leaves 

 of certain species. The fruits vary considerably in the different stages of growth. 



* Leaves solitary, orbicular or reniform, 3~5-7-lobed or partite. Petals valvate. Stems prostrate, 



creeping except in 6, often matted. 

 Leaves deeply divided. Peduncles elongated. Pruits on strict pedicels . . 

 Umbels sessile or very shortly peduncled 

 Leaves 3-5-foliolate 



Leaves 5-7partite, acutely toothed. Peduncles slender. Umbels many- 

 flowered 

 Leaves obscurely 3-Y-lobed, glabrous. Carpels large, flat 

 Stems erect or suberect. Carpels turgid, faintly keeled 

 Leaves obscurely 3-7-lobed, pubescent or hairy. Umbels 5-10-flowered . . 

 Leaves distinctly 5-7-lobed, hispid or tomentose. Umbels many-flowered 

 Leaves nearly glabrous, Jin. in diameter, 5-7-lobed. Umbels few-flowered 



*' Stems rather stout. Leaves fascicled. Petals imbricate. 

 Leaves broadly cordate. Umbels 2-3-flowered. Pruits large . . . . 10. H. asiatica. 



1. H. elongata, A. Cunn., Precurs n. 495. Stems filiform, prostrate, 

 weak, pilose or rarely glabrate. 6in.— 12in. long. Leaves oa long petioles, 

 distant, deeply 3— 7-lobed ; lobes acutely toothed, glabrate or hairy on both 

 surfaces. Stipules minute. Peduncles exceeding the leaves, very slender ; 

 bracts minute. Umbels 12— 30-flowered, Jin.— |in. in diameter. Pedicels strict, 

 slender. Flowers small. Fruits ovate-orbicular, truncate at base, not emargi- 

 nate, flattened. Carpels with 1 rib on each face. — Hook, f., Fl. N.Z. i. 84 ; 

 Handbk. 85. H. concinna, Col. in Trans. N.Z.I, xvii. (1884) 239. 



Var. echinella. Margins of the sinus often sharply toothed. Carpels sparingly pubescent or 

 almost bristly ; sometimes the pubescence is confined to the carpellary rib. — H. echinella, Col. in 

 Trans. N.Z.I, xx. 191. 



NORTH and SOUTH Islands Mangonui to Southland, but often local. Sea-level to 2,000ft. 

 Nov. to Peb. 



2. H. americana, L., Sp. PI. 234. Perfectly glabrous. Stems 3in.- 

 6in. long, much branched, flaccid, matted. Leaves orbicular, reniform, shining, 

 with 5-7 shallow lobes, crenate, iin.— iin. in diameter ; petioles lin.— 1 Jin. long. 

 Umbels axillary or leaf-opposed, 2— 6-flowered, sessile or very shortly peduncled. 

 Flowers sessile or subsessile. Fruits glabrous or shortly hispid. Carpels with 



1 rib on each face ; margins acute. — Hook, f., Fl. N.Z. i. 84; Handbk. 85. 



24=:= 



