EXOGENOUS OR DICOTYLEDONOUS PLANTS. 425 



ifraga, Mitella, &c. Roots somewhat astringent, in Ileucliera so much 

 so that H. Americana is called Alum-root. Hydrangie^ : shrubs, 

 with simple opposite leaves and no stipules. Ex. Hydrangea and 

 Philadelphus, the latter polyandrous. BauerejE : Australian 

 shrubs, with opposite and compound sessile leaves and no stipules. 

 CuNONiE^ : woody plants, with opposite simple or compound leaves 

 and interpetiolar stipules. EscalloniejE : woody plants, with 

 alternate simple leaves and no stipules. Ex. Escallonia, of South 

 America, Itea. 



832. Ord. HamamelaCCSe {Witch-Hazel Family). Shrubs or small 

 trees, with alternate simple leaves, without stipules. Flowers often 

 polygamous. Petals valvate in ajstivation. Stamens twice as many 

 as the petals, half of them sterile ; or numerous, and the petals none. 

 Summit of the two-celled ovary free from the calyx, a single ovule 

 suspended from the summit of each cell : styles two, distinct. Cap- 

 sule cartilaginous or bony. Seeds bony, with a small embryo in 

 hard albumen. — Ex. Hamamelis (Witch-Hazel), Fothergilla. A 

 small order, of little importance. Hamamelis is remarkable for 

 flowering late in autumn, just as its leaves are falling, and perfecting 

 its fruit the following spring. To this order is now appended the 

 genus Liquidambar, or Sweet-Gum, which has been taken as the 

 type of a distinct order ; but it is rather a reduced and apetalous 

 form of the present order. It may stand as a suborder, viz. 



833. Subord. BalsamiflUffi {Sweet-Gum Family), consisting of a 

 few trees, with alternate palmately-lobed leaves, and deciduous 

 stipules ; the moncjcious flowers in rounded aments or heads, desti- 

 tute of floral envelopes ; the indurated capsules forming a head : 

 they are two-beaked, opening between the bealis, the cells ripening 

 one or two seeds, although the ovules are numerous. The Sweet-gum 

 is so called from a fragrant balsam or storax which it exudes. 



834. Ord. Umbelllferae {Parsley Family). Herbs, with hollow 

 stems, and alternate, dissected leaves, with the petioles sheathing 

 or dilated at the base. Flowers in simple or mostly compound um- 

 bels, which are occasionally contracted into a kind of head. Calyx 

 entirely coherent with the surface of the dicarpellary ovary; its 

 limb reduced to a mere border, or to five small teeth. Petals five, 

 valvate in asstivation, inserted, with the five stamens, on a disk 

 which crowns the ovary ; their points inflexed. Styles two ; their 

 bases often united and thickened, forming a stylopodium. Fruit 

 dry, a cremocarp, consisting of two united carpels, at maturity sepa- 



8G* 



