344 Key to the System of 



ISOTOMA. 



1527. Leaves large, pinnatilobed. 



Perennial, ascending or erect, excessively acrid, of un- 



Eleasant odour, glabrous except portions of the flower ; 

 javes scattered, irregularly dissected or lobed, the 

 segments or lobes narrow ; flower-stalks elongated, some- 

 times very long, all axillary and solitary ; flowers very 

 large ; corolla usually outside pale, the lobes inside 

 blue or somewhat violet, the tube longer than the 

 lobes, slightly curved ; filaments and style beset with 

 short hairlets ; anthers exserted ; fruit obconic -ellipsoid, 

 terminated by the narrow calyx-lobes, two-celled ; seeds 

 numerous, foveolar-rough. I. axillaris. 



Leaves small, lobeless. 



A small perennial creeping plant, beset with very minute 

 hairlets ; leaves scattered, firm, from linear- to ovate- 

 elliptical, entire or somewhat denticulated ; flower-stalks 

 from as long as the leaves to much longer ; flowers small ; 

 corolla blue or not rarely almost white, the tube inside 

 as well as the filaments beset with short hairlets ; fruit 

 small, nearly hemi-ellipsoid, two-celled, terminated by 

 the short lobes of the calyx ; seeds many, smooth. 



I. fluviatilis. 



LOBELIA. 



1528. Flowers terminal 1529 



Flowers axillary 1532 



1529. Flowers singly terminating very elongated stalks. 



Ascendant, glabrous ; lower leaves mostly cuneate-obovate, 

 incised, the others from lanceolar to nearly linear and 

 somewhat indented ; flowers rather large, on thin elon- 

 gated stalks, terminating stems and branches ; corolla 

 blue inside, its lowest lobe ovate-cuneate ; fruit some- 

 what bulging on the upper side ; seeds numerous, minute. 



L, rhombifolia. 



Flowers forming unilateral racemes ... ... ... 1530 



1530. Stems somewhat turgid and succulent. 



Annual, glabrous ; stem usually branchless ; leaves narrow- 

 linear or thread-like, usually entire; bracts linear, pointed; 

 stalklets shorter than the flowers ; corolla blue inside, its 

 upper lobes curved and much pointed, glabrous, lower 

 lobes narrow-lanceolar and pointed ; fruit very bulging 

 on the upper side ; seeds brown, very minute, almost 

 dust-like. L. microsperma. 



