132 
UMBELLIPERJE. 
[. Hydrocotyle . 
narrow commissure ; 5 primary ribs distinct, especially the dorsal one ; 
carpophore undivided. — Prostrate perennial herbs of swampy ground, 
with entire leaves, small lanceolate bracts and simple or irregularly 
compound umbels. Distrib. Cosmopolitan. Species 70. 
Leaves not peltate. Flowers in simple heads. 
Heads one from each node 1. H. sibthorpioides. 
Heads several from each node 2. H. asiatica. 
Leaves peltate. Flowers in compound whorls . . . 3. H. bonariensis. 
1. H. sibthorpioides, Lam.; DC. Prod. iv. 66. Stems very 
slender, wide-trailing, glabrous. Leaves orbicular or rather broader 
than long, in. broad, membranous, glabrous, shallowly lobed, the 
lobes crenate ; petiole \-2 in. long, from a narrow deep basal sinus. 
Heads solitary, dense, globose, on slender peduncles as long as the 
petioles, 8-10-flowered ; pedicels 0. Fruit in. broad and deep, 
' only the 5 primary ribs distinct. A. Rich. Monog. Hydrocot. t. 8. 
Mauritius, in marshy ground, Bouton ! Endemic. 
2. H. asiatica, Linn. ; DC. Prod. iv. 62. Stems in dense rosettes, 
wide-trailing, and producing rosettes of leaves and peduncles at the 
often rooting nodes, usually glabrous. Leaves round, petioled from a 
deep basal sinus, crenate, in. broad ; petioles 1-8 in. long. Flowers 
1-4 in dense heads on copious short peduncles from the nodes, each 
cluster subtended by a pair of lanceolate bracts ; pedicels none. Fruit 
3^2 in. deep, corky ; mericarps rounded on the back, with both second- 
ary and primary ribs developed as slender lines. H. ficarioides and 
nummularioides, DC. Prod. loc. cit. 
Mauritius and Seychelles, common in swampy places. Cosmopolitan in 
warmer regions. Bevilaqua. 
3. H. bonariensis, Lam. ; DC. Prod. iv. 60. Stems slender, wide- 
trailing, glabrous, rooting at the distant nodes. Leaves round, peltate, 
glabrous, crenulate or subentire, 1-4 in. broad ; petioles reaching J ft. 
long. Peduncle 4-24 in. long ; umbel with many rays, bearing lateral 
and terminal whorls of flowers and one from the centre; pedicels 
finally in. long ; bracts linear, shorter than the pedicels. Fruit 
in. broad, the mericarps acutely keeled and showing only the 
distinct primary ribs. H. petiolaris, DC. Prod. loc. cit. 
Mauritius and Rodriguez, in swampy ground. Spread through Tropical Africa 
and common in Tropical America. 
* Carum {Tr achy sper mum) dichotomum , Benth. Gren. Plant, i. 891 
(Pimpinella dichotoma, Linn.; DC. Prod. iv. 123), a commonly cul- 
tivated Anise from Spain, has become subspontaneous in some places 
in Mauritius. It is a slender erect glabrous annual, 1-1 1 feet high, 
with decompound leaves with minute linear lobes, compound umbels 
without either involucre or iuvolucel, emarginate petals with an in- 
flexed point and minute laterally-compressed mericarps with five 
equal ribs. Anis sauvage. 
