ERODIUM.] GERAXIACE&. 79 



3. OX A LI S, L. WOOD-SORREL. 



Acid herbs. Leaves radical or alternate, stipulate or exstipulate, com- 

 pound, usually 3-foliolate. Flowers on axillary 1- or more-flowered 

 peduncles, regular. Sepals 5, imbricate in bud. Petals 5, twisted in bud. 

 Stamens 10, free or connate at the base. Disk 0. Ovary 5-lobed, 5-celled ; 

 styles 5, stigmas terminal ; ovules 1 or more in each cell. Capsule locu- 

 lioidal, valves adhering by the septa to the axis. Seeds with an elastic 

 dehiscent fleshy coat, testa crustaceous, albumen fleshy ; embryo straight. 

 DISTKIB. 3 or 4 species widely dispersed, the rest S. African and S. Ame- 

 rican ; species 220. ETYM. o|u?, add. Leaflets pendulous at night, often 

 sensitive to light. Tetramorphic flowers occur ; petaliferous large, others 

 minute apetalous and very fertile. 



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

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

 Moist shady places, ascending to near 4,000 ft. in the Highlands ; fl. April- 

 Aug. Glabrous or pilose. Rootstock creeping, scaly. Petioles 3-6 in. ; leaf- 

 lets obcordate, ^- in., often purple beneath. Scape axillary, slender, 

 2-bracteate about the middle, floicer g^ in. diam. Sepals oblong. Petals 

 obovate, white veined with purple, erose, cohering above the claw. Capsule 

 erect, 5-gonal ; cells 2-3-seeded. DISTRIB. Europe (Arctic), N. Africa, Siberia 

 and W. Asia to the Himalaya, E. and W. 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 ; fl. June-Sept. Very variable in size and habit ; annual or biennial. 

 Stems 6-16 in. Leaves as in 0. Acetosella. Flowers | in. diam., subumbellate, 

 very long-peduncled, yellow. Seeds transversely ribbed. DISTBIB. Ubi- 

 quitous, except in very cold regions. 



0. .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, capsule glabrous, pedicel spreading. 

 A weed in Cheshire and south of it, local ; not indigenous ; fl. June-Sept. 

 Similar to and distribution of 0. cwniculata, of which it is perhaps a sub- 

 species. 



A. IMPA'TIENS, L. BALSAM. 



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

 glandular. Flowers irregular, resupinate, 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. 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, valves 5, elastic, springing away from the placentas. 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 burst- 



