DICOTYLEDONES— THALAMIFLOR^ 265 



Properties and Uses. — The plants of this order generally 

 abound in an acrid principle, which in some is even vesicant. 

 This acridity is, however, very volatile, so that in most cases it 

 is dissipated by drying, or by infusing them in boiling, or even 

 sometimes in cold water ; it varies also in different parts of the 

 same plant, and even in the same parts at different seasons. 

 Some plants contain in addition a narcotic principle ; and when 

 these principles are in excess, they are virulent poisons. Gene- 

 rally the plants of this order are to be regarded with suspicion, 

 although some are simply bitter and tonic. 



Order 47. Dilleniace^, the Dillenia Order. — C h a r a c t e r. — 

 Trees or shrubs, sometimes climbing ; rarely herbs. Leaves 

 alternate, entire or dentate, rarely pinnatifid or trifld ; generally 

 exstipulate. Sepals 5, rarely 3-4 or oo , persistent. Petals 5 or 

 fewer, hypogynous, imbricate, free. Stamens oo , rarely definite, 

 10 or fewer, hypogynous, free, or united at their bases. Carpels 

 1-QO , generally free. Ovules 1- , anatropous. Seeds 1 or ie'w , 

 arillate. Mnibryo minute in fleshy albumen. 



Diagnosis. — Stipules absent, except in rare cases. Sepals 

 and petals 5 each, hypogynous ; the former persistent in two 

 rows, the latter with an imbricate aestivation. Carpels more 

 or less distinct. Seeds numerous, arillate ; albumen fleshy, 

 homogeneous. 



Dilleniacese differ from Eanunculaceae in habit, and in their 

 having a persistent calyx and arillate seeds ; from Magnoliacese 

 in the latter possessing a multiseriate perianth. 



Distribution and Numbers. — The plants of this order occur 

 chiefly in Australia, India, and equinoctial America ; a few 

 species have been also found in equinoctial Africa ; none occur 

 in Europe. Illustrative Genera : — Dillenia, Linn. ; CandoUea, 

 Labill. There are 17 genera and nearly 200 species belonging to 

 this order. . 



Properties and Uses. — These plants have generally astringent 

 properties ; they have been used as vulneraries, and for tanning 

 in Brazil. 



Order 48. Calycanthace^, the Calycanthus Order. — Cha- 

 r a c t er. — Shrubs with opposite entire exstipulate leaves. Sepals 

 Sjudpetals arranged in several series, inserted on a hollow urceo- 

 late receptacle. Stamens cc , closing the throat of the receptacle ; 

 inner ones sterile. Carjpels oo , free ; situated in the cavity of 

 the hollow receptacle. Ovules solitary or two together, ana- 

 tropous. i^'ritii a number of achenes. Seeds erect, exalbuminous. 

 Cotyledons foliaceous, convolute. 



