[Illustration: FIG. 101.--Types of _Aphanocyclæ_ (_Polycarpæ_). _A-H_, _Berberidaceæ_. _A_, flower of barberry (_Berberis_), × 2. _B_, the same in section. _C_, a stamen, showing the method of opening, × 3. _D_, flower of may-apple (_Podophyllum_), × ½. _E_, section of the ovary of _D_, × 1. _F_, diagram of the flower. _G_, ripe fruit of twin-leaf (_Jeffersonia_), opening by a lid, × ½. _H_, section of seed, showing the embryo (_em._), × 2. _I_, young leaf and cluster of male flowers of moon-seed, _Menispermum_ (_Menispermeæ_), × 1. _J_, a single male flower, × 2. _K_, section of a female flower, × 2. _L_, ripe seed, × 1. _M_, section of _L_, showing the curved embryo.] The last two families of the order, the laurel family (_Laurineæ_) and the nutmeg family (_Myristicineæ_) are mostly tropical plants, characterized by the fragrance of the bark, leaves, and fruit. The former is represented by the sassafras and spice-bush, common throughout the eastern United States. The latter has no members within our borders, but is familiar to all through the common nutmeg, which is the seed of _Myristica fragrans_ of the East Indies. "Mace" is the "aril" or covering of the seed of the same plant. The second order of the _Aphanocyclæ_ comprises a number of aquatic plants, mostly of large size, and is known as the _Hydropeltidinæ_. The flowers and leaves are usually very large, the latter usually nearly round in outline, and frequently with the stalk inserted near the middle. The leaves of the perigone are numerous, and sometimes merge gradually into the stamens, as we find in the common white water-lily (_Castalia_). [Illustration: FIG. 102.--Types of _Aphanocyclæ_ (_Hydropeltidinæ_). _A_, yellow water-lily, _Nymphæa_ (_Nymphæaceæ_), × ½. _B_, a leaf of the same, × ⅙. _C_, freshly opened flower, with the large petal-like sepals removed, × ½. _p_, petals. _an._ stamens. _st._ stigma. _D_, section of the ovary, × 2. _E_, young fruit, × ½. _F_, lotus, _Nelumbo_ (_Nelumbieæ_). × ⅙. _G_, a stamen, × 1. _H_, the large receptacle, with the separate pistils sunk in its surface, × ½. _I_, section of a single pistil, × 2. _ov._ the ovule. _J_, upper part of a section through the stigma and ovule (_ov._), × 4.]