=B.= CALLEÆ. Flowers hypogynous, naked, ☿.--_Calla_ (_C. palustris_). All flowers in the spike are fertile, or the upper ones are ♂; 6–9 stamens; ovary unilocular with many basal ovules. Marsh-plants with creeping rhizome and cordate leaves.--_Monstera_, _Rhaphidophora_, etc. =C.= ARINEÆ. Flowers monœcious, naked, ♂-flowers on the upper, ♀ on the lower part of the spadix.--_Arum_ (Fig. 301). The spadix terminates in a naked, club-like portion (_k_); below this is a number of sessile bodies (rudimentary flowers), with broad bases and prolonged, pointed tips (_b_); underneath these are the ♂-flowers (_m_), each consisting only of 3–4 short stamens, which eject vermiform pollen-masses through the terminal pores; then follow, last of all, ♀-flowers (_f_), each of which consists of one unilocular ovary, with several ovules. Perennial herbs, tuberous, with cordate leaves.--~_Dracunculus_; _Biarum_; _Arisarum_; _Pinellia (Atherurus) ternata_ with leaves bearing 1–2 buds. _Zantedeschia æthiopica_ (_Richardia_, Nile-lily); ♂, 2–3 stamens; ♀ with 3 staminodes, 1–5-locular ovary (S. Africa.)--In some genera sterile flowers are present between the ♂ and ♀ portions of the spadix (_e.g._ in _Philodendron_); in _Ambrosinia_ a lateral, wing-like broadening of the axis of the spadix divides the cavity of the spathe into two chambers, the anterior containing one ♀, and the posterior 8–10 ♂-flowers in two series; in some the stamens in the single ♂-flowers unite and form a columnar “synandrium” (_e.g._ in _Dieffenbachia_, _Colocasia_, _Alocasia_, _Caladium_, _Taccarum_, _Syngonium_). A remarkable spadix is found in _Spathicarpa_; it is united for its entire length, on one side, with the spathe, and the flowers are arranged upon it in rows, the ♀ to the outside, and the ♂ in the middle (_Zostera_ has a similar one).--_Pistia_ similarly deviates considerably, it is a floating water-plant, with hairy, round rosettes of leaves; in it also the spathe and spadix are united; at the base a ♀-flower is borne, which consists of one unilocular ovary, and above several ♂-flowers, each composed of two united stamens.~