GERANIACE^. 357 



Oeder XXXII. GERANIACE^. 



By W. Trelease. 



Herbaceous or suffrutescent terrestrial or marsh plants (in our region), of 

 various duration. Leaves alternate or occasionally opposite or pseudo- verticil- 

 late, simple, parted or compound, mostly cut-toothed, the petiole commonly with 

 stipular enlargements. Flowers either evidently cymose, solitary and terminal, 

 or seemingly racemose or umbellate, usually showy, variously colored, perfect, 

 mostly 5-merous (3-6-merous in Limnanihece, and the earliest flower of Oxalis 

 not infrequently 6-merous), symmetrical, nearly hypogynous. Glands of the 

 receptacle as many as the sepals and opposite them (reduced and opposite the 

 petals in Oxalis), or wanting when the flower is spurred. Sepals and petals dis- 

 tinct or nearly so. Stamens mostly twice as numerous as the petals, distinct (or 

 somewhat connate in Oxalis and Impatiens) ; anthers round-oval, more or less 

 versatile, 2-celled, with longitudinal dehiscence. Carpels as many as and alter- 

 nate with the sepals, united about a columnar prolongation of the receptacle 

 except in Limnanthece ; ovary usually deeply lobed, its cells 1-many-ovuled; 

 styles mostly united below, the capitate or lateral stigmas usually distinct. Seeds 

 exalbuminous or nearly so except in Oxalis; embrj/o straio-ht or bent the 



cotyledons somewhat plicate and lobed in the genera with dissected leaves. 



Five very distinct tribes or suborders, which are generally treated as orders by 

 Continental writers. 



Tribe I. GERANIE^. Flowers regular or nearly so, 5-merous. Sepals imbricate, 

 persistent, enlarging somewhat in fruit. Petals imbricate, deciduous. Antherif- 

 erous stamens as many as and opposite the sepals, or twice as many, with persist- 

 ent filaments. Glands of receptacle conspicuous. Carpels 2-ovuled, becoming 

 1-seeded, breaking elastically from the persistent fluted beak ; seeds with little 

 albumen ; embryo with sinuously folded incumbent cotyledons. 



1. GERANIUM. Leaves radiately divided. Peduncles 1- or mostly 2-flowered. Flowers 

 regular. Stamens with antliers 10, except in G. prisillum. Ripened carpels dehiscent on 

 the inner suture, the stylar portion merely arched, and nearly glabrous on the inner side • 

 seed often alveolate. 



2. ERODIUM. Leaves often pinnately lobed or dissected. Peduncles mostly umbellately 

 several-flowered. Upper petals slightly smaller than the others. Antlieriferous stamens 5. 

 Ripened carpels sharp-pointed below, at most tardily dehiscent, the stylar prolongation when 

 freed spirally twisting below, bearded on the inner side ; seed smooth. 



Tribe IT. PELARGONIEiE. Flowers somewhat irregular. Sepals imbricate, the 

 posterior spurred. Antheriferous stamens neither as many nor twice as many as 

 the petals. Glands of receptacle wanting. Seeds exalbuminous. 



3. PELARGONIUM. Spur decurrent and adnate to the pedicel. Stamens 10, or fewer 

 by abortion, 7 usually with antliers. Carpels 5, 2-ovuled, at length dry, 1-seeded, plumed 

 beaked, breaking from the axis and coiling as in Erodium. 



4. TROP.^OLUM. Spur free. Stamens 8, all with anthers. Carpels 3, 1-ovuled, fleshy, 

 beakless. 



