141 



CXXIV. TROP^OLEiE. The Nasturtium Tribe. 



Trop^ole-^!, J71SS. Mem. Mus. 3. 447- (1817) ; Dec. Prodr. 1. 693. (1824.) 



Diagnosis. Polypetalous dicotyledons, with definite hypogynous dis- 

 tinct stamens, concrete carpella, an ovarium of 3 cells with the placentae 

 in the axis, an imbricated calyx with 1 of the sepals spurred, unsymmetrical 

 flowers, definite pendulous ovules, and indehiscent fruit. 



Anomalies. Magallana has winged fruit, 1-celled and 1-seeded by 

 abortion. In Trop. pentaphyllum, according to Aug. St. Hilaire {Pl.Us.4\.), 

 the calyx is valvular, and the petals only 2. 



Essential Chahacter. — ■S'epafe 5, the upper one with a long distinct spur; cesti- 

 vation quincuncial. Petals 5, unequal, irregular, the 2 upper sessile and remote, arising 

 from the throat of the calyx, the 3 lower stalked and smaller, sometimes abortive. Stamens 

 8, perigynous, distinct; anthers innate, erect, 2-celled. Ovarium 1, 3-cornered, made up 

 of 3 carpella ; style 1 ; stigmas 3, acute ; ovula solitary, pendulous. Fruit indehiscent, 

 separable into 3 pieces from a common elongated axis. Seeds large, without albumen, fill- 

 ing the cavity in which they lie ; embryo large ; cotyledons 2, straight, thick, consolidated 



together into a single body ; radicle lying within projections of the cotyledons Smooth 



herbaceous plants, of tender texture and with an acrid taste, trailing or twining. Leaves 

 alternate, without stipuls, petiolate, with radiating ribs. Peduncles axillary, l-flowered. 



Affinities. Very near Geraniaceae, with which they agree even in 

 their spur (which in Pelargonium is often present, but adnate to the pedicel), 

 and also Balsaminese, and Hydrocerese, from which they differ chiefly in the 

 structure of their fruit. 



Geography. All natives of South America, mostly upon high land. 



Properties, The fleshy fruit of Tropseolum majus is acrid, and pos- 

 sesses the properties of Cress ; and M. Decandolle remarks, that the cater- 

 pillar of the Cabbage butterfly feeds exclusively upon Cruciferae and Tro- 

 pseolum. The root of Tr. tuberosum is eaten in Peru. Tropseolum penta- 

 phyllum is used in Brazil as an antiscorbutic, under the Portuguese name 

 of Chagas da Miuda. PL Usuelles, 41. 



Example. Tropaeolum. 



CXXV, HYDROCERE^. 



HydrocerEjI;, Blume Bijdr. 241. (1825.) 



Diagnosis, Polypetalous dicotyledons, with definite hypogynous sta- 

 mens, concrete carpella, an entire ovarium of several cells with placentiE in 

 the axis, an imbricated calyx, one of the sepals of which is spurred, sym- 

 metrical flowers, definite pendulous ovules, and a drupaceous fruit. 



Anomalies. 



Essential Character — Sepals 5, deciduous, coloured, unequal; the lowermost 

 elongated into a spur. Petals 5, hypogynous, unequal; the upper arched. Stamens 5, 

 hypogynous, connate at the apex ; anthers slightly connate, 2-celled, bursting at tlie apex. 

 Ovarium 5-celled, 5-angled, with 2 or 3 ovula in each cell ; stigmas 5, sessile, acute. Fruit 

 succulent, with 5 cells, each of which has a bony hard lining, and contains a single seed. 

 Seed solitary, without albumen ; cotyledons plano-convex ; radicle superior. — Herbaceous. 

 Stems angular. Leaves alternate, without stipulaj, serrated. Peduncles axillarj^, many, 

 flowered. 



Affinities, Closely related to Balsaminese and Tropeeolese, from 

 which they are only distinguished by their symmetrical flowers and drupa- 

 ceous fruit. 



