159 CLASS HEPTANDRIA. 



the flowers have no proper corolla, but the six stamens and three 

 pistils are surrounded by a six-leaved calyx, or what, in this case, 

 may be called a perianth. 



The Colchicum or meadow-saffron of England is a medicinal 

 plant, in some repute among physicians. The root is a larjje, egg- 

 shaped bulb ; in spring several narrow leaves arise, but the flower 

 does not appear tiU September. The germ hes buried in the root 

 all winter, and is raised in spring, to perfect its seeds before the next 

 season. The flowers are pale purple. 



CLASS VII. — HEPTANDRIA. 

 Order Monogyrda. 



, The first order of this class contains the chick winter-green, ( Tri- 

 entalis ;) this plant has a calyx with 7 leaves, or sepals, and the co- 

 rolla is 7-parted. One species is said to defend its stamens against 

 injury from rain, by closing its petals and hanging down its head in 

 wet weather. 



The cultivated Horse-chestnut, jEscuIus, 

 Fig 131. (Fig- 131,) is a native of the northern part 

 of Asia, and was introduced into Europe 

 about the year 1500; it was not probably 

 brought to America until some time after 

 the settlement of this country by Euro- 

 peans. It is a small tree which produces 

 white flowers, variegated with red, crowded 

 together in the form of a panicle ; the whole 

 resembhng a pyramid. In appearance it is 

 very showy, and the more agreeable to us, 

 as we have so few trees whose flowers are 

 conspicuous. The blossom is very irregular in its parts, that is, its 

 other divisions do not correspond with the usual number of stamens ; 

 the stamens, however, do not vary as to number. The seeds have a 

 resemblance to chestnuts, but their taste is bitter. There are several 

 native species of this plant in the southern and western stntes. The 

 horse-chestnut exhibits in its buds, in a very conspicuous manner, 

 the woolly envelope which surrounds the young flowers, the scales 

 which cover this envelope, and the varnish which covers the whole. 

 The stems and branches of this tree afford good subjects for study- 

 ing the formation and growth of woody or exogenous stems. 



Order Tetragynia. 



There is but one plant with four pistils known in the class Hep- 

 tandria ; this alone constitutes the fourth order ; its common name 

 is lizard's-tail, (Saicrurus.) It has arrow-shaped leaves, flowers 

 destitute of a corolla, and growing upon a spike ; it is to be found in 

 stagnant waters. 



Oi^er Heptagynia. 



The Septas, a native of the Cape of Good Hope, is considered as 

 the most perfect plant in this class ; it has 7 stamens, 7 pistils, 7 pe- 

 tals, a calyx 7-parted, and 7 germs, (one to each pistil,) which germs 

 /ecome 7 capsules, or seed vessels. 



Heptandria is the smahest of all the classes ; we do not find here, 

 as in most of the other classes, any natural families of plants ; but 

 the few genera which it contains differ not only in natural characters 

 from other plants, but they seem to have no general points of re- 

 semblance among themselves. 



Colchicum— What plant is in the 1st order of the 7th class 7— What is said of the 

 Horse-chestnut 1— Saururus— VVhat example is given of the order Heptagynia 1— Re- 

 marks upon the class Heptandria. 



