84 GERANIACE^E. [Oxalis. 



Capsule loculicidal, valves adhering by the septa to the axis. Seeds with 

 an elastic dehiscent fleshy coat, testa crtistaceous, albumen fleshy ; embryo 

 straight. — Distrib. 3 or 4 species widely dispersed, the rest S. African 

 and S. American ; species 220. — Etym. o£vs, acid. — Leaflets pendulous at 

 night, sensitive to light. 



O. Acetosel'la, L. ; stemless, leaves all radical 3-foliolate, stipules 



broad membranous, scape 1 -flowered. Wood-sorrel. 



Moist shady places, N. to Orkneys ; ascends to near 4,000 ft. in the High- 

 lands ; Ireland ; Channel Islands ; fl. April-Aug. — Glabrous or hairy. Root- 

 stock creeping, scaly. Petioles 3-6 in. ; leaflets obcordate, ^-§ in., often 

 purple beneath. Scape axillary, slender, 2-bracteate about the middle. 

 Flower |-| in. diam., dimorphic, larger |-£ in. diam. ; smaller cleistogamous. 

 Sepals oblong. Petals obovate, white veined with purple, rarely rose-purple, 

 erose, cohering above the claw. Capsule erect, 5-gonal ; cells 2-3-seeded. 

 Seeds ribbed. — Distrib. Europe (Arctic), N. Africa, N. and "W. Asia to the 

 Himalaya, N. America. 



0. cornicula'ta, L. ; pubescent, stems branched procumbent without 



runners, leaves all cauline 3-foliolate, stipules adnate, peduncles axillary 



2-3-flowered, fruiting pedicels deflexed, capsules downy. 



"Waste shady places, local, possibly indigenous in S.W. England, not north of 



it ; Channel Islands ; fl. June-Sept. — Yery variable in size and habit ; 



annual or biennial. Stems 6-16 in. Leaves as in O. Acetosel/a. Flowers £ 



in. diam., subumbellate, very long-peduncled, yellow. Seeds transversely 



ribbed. — Distrib. Ubiquitous, except in very cold regions. 



O. stric'ta, L. ; subglabrous, stem erect with copious runners at the 

 base, leaves as in 0. corniculata but often whorled and stipules minute, 

 peduncles 2-8-flowered, capsules glabrous, fruiting pedicels spreading. 

 A weed in Cheshire and south of it, local, not indigenous. ; casual in Ireland ; 



fl. June-Sept. — Similar to and distribution of O. comiculata^ of which it is 



perhaps a sub-species. 



4. IMPA'TIENS, L. Balsam. 



Herbs, rarely shrubby. Leaves opposite or alternate, stipules 0: or 

 glandular. Flowers irregular, resnpinate,. on 1- or more-flowered axillary 

 peduncles. Sepals 3, rarely 5, petaloid, imbricate ; 2 anterior (if present) 

 minute ; 2 lateral small, flat ; posterior large, produced into a hollow spur. 

 Petals 3 ; anterior external in bud, large ; lateral 2-lobed, each formed by 

 a connate lateral and posterior petal. Stamens 5, filaments short broad ; 

 anthers cohering. Disk 0. Ovary oblong, 5-celled ; stigma sessile, 

 5-toothed ; ovules many in each cell, 1-seriate. Capsule loculicidal, valve3 

 5 elastic separating from the placentas and then twisting. Seeds smooth 

 or villous, albumen ; embryo straight. — Distrib. Mountains of trop. 

 Asia and Africa ; rare in temp. Europe, N. America, N. Asia, and S. Africa ; 

 species 135. — Etym. The Latin name, from the ripe capsules bursting 

 when touched. — The anterior lateral sepals occur in a few Indian species. 

 Cleistogamous flowers occur in /. noli-me-tangere and I. fulva. 



