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THE LOWER DICOTYLEDONS. 



R. bulbosus flowers chiefly in early summer (May-July) ; R. repens 

 from May to September ; It. acris from April to November (all the 

 year round in sheltered places). 



The three commonest species of Buttercup agree in many respects 

 e.g. in having five sepals and five petals, etc. but are distinguished by 

 the following, amongst other, characters : 



The Celery-leaved Buttercup (R. sceleratus) is a more decidedly 

 moisture-loving plant than the other Buttercups (given above), grow- 

 ing chiefly in ditches, and it is annual. It differs from the three com- 

 monest species in having no scale on the nectary at the base of the 

 petals, and its akenes are raised on an oblong receptacle (owing to 

 growth of the latter after fertilisation). The flowers are small 

 (5 mm.), with pale yellow petals, hardly longer than the sepals 

 which are reflected as in R. bulbosus. Goldilocks (R. auricomus), 

 in woods, is like R. acris but is less hairy and not so tall, and lower 

 leaves have fewer, shallower, and blunter lobes ; its flowers (March- 

 May) often have, instead of the 5 normal petals, numerous imperfect 

 ones passing gradually into stamens, and there is no scale over the 

 nectar-pit. 



Of the remaining Buttercups, the commonest species is the Corn B. 

 (R. arvensis), a troublesome cornfield weed, with tall (1 to 2ft.) stem, 

 growing with the corn and ripening its fruits at harvest-time, the 

 flowers (May- July) small (12 mm. across) and pale yellow, akenes few 

 but large, covered with hooked spines, the style also forming a stout 

 hook. What are the advantages to the Corn Buttercup of (1) the 

 unbranched stem, (2) the hooked akenes ? These two species are 

 annuals ; R. hirsutus is rare in Scotland and not found in Ireland, 

 while R. arvensis is very rare in Ireland. 



The ordinary Buttercups are sometimes called "Crowfoots" from 

 the shape of the leaves in most species, but the two "Spear worts," 

 which grow in marshy places, are easily distinguished by their long 

 and narrow tapering leaves. Like ordinary Buttercups they have 



