32. Sepals 3, subequal. Anthers opening by a terminal lid. Staminodes none. Stigma 1. Leaves scattered. Flowers in umbels. _Mayaca_, =23. Mayacaceae.= Sepals 3, very unequal, or 2. Anthers opening by longitudinal slits. Staminodes 3. Stigmas 3. Leaves all radical. Flowers in heads or spikes. _Xyris_, =24. Xyridaceae.= 33. (16.) Leaves divided. Woody plants. Seeds albuminous. =18. Palmae.= Leaves undivided. Herbaceous plants. 34 34. Plants without green colour, growing upon mould. Leaves reduced to scales. Perianth of 6 petaloid segments. Seeds albuminous. _Sciaphila_, =15. Triuridaceae.= Plants of green colour, growing in the water. Leaves well developed. Perianth of 6 segments differentiated into sepals and petals, or of 1-3 segments. Seeds exalbuminous. 35 35. Perianth consisting of 1-3 coloured segments. _Aponogeton_, =10. Aponogetonaceae=. Perianth consisting of 6 segments more or less distinctly differentiated into sepals and petals, rarely in the female flowers only of 3 greenish segments. 36 36. Ovules numerous, covering the whole inner surface of the carpels. =13. Butomaceae.= Ovules 1-2, rarely more, and then all inserted at the upper suture of the carpels. =12. Alismataceae.= 37. (15.) Stamen 1. Flowers irregular. 38 Stamens 2-18. Flowers usually regular. 41 38. Staminodes small or wanting. Ovary 1-celled with numerous ovules. Style adnate to the filament. Seeds exalbuminous. Leaves usually with longitudinal nervation. =44. Orchidaceae.= Staminodes, at least some of them, petal-like. Ovary 1-celled with a single ovule or more frequently 3-celled. Seeds albuminous. Leaves with pinnate nervation. 39 39. Anthers 2-celled. Sepals united below. Flowers symmetrical. =40. Zingiberaceae.= Anthers 1-celled. Sepals free. Flowers asymmetrical. 40 40. Ovules several or many in each ovary-cell. Seeds with straight embryo. Leaf-stalk not thickened. _Canna_, =41. Cannaceae=. Ovules solitary in each cell. Seeds with curved embryo. Leaf-stalk thickened towards the apex or throughout its whole length. =42. Marantaceae.= 41. Stamens 2-4, usually 3. 42 Stamens 5-18, usually 6. 45 42. Perianth-segments sepal-like or the outer sepal-, the inner petal-like. Ovary 1-celled, sometimes incompletely 6-celled. Seeds exalbuminous. Water plants. =14. Hydrocharitaceae.= Perianth-segments petal-like. Ovary usually 3-celled. Seeds albuminous. Land-or marsh-plants. 43 43. Stamens opposite the outer perianth-segments. Anthers opening outwards or laterally. =38. Iridaceae.= Stamens alternating with the outer or with all perianth-segments. Anthers opening inwards or laterally. 44 44. Leaves well developed, green. Inner perianth-segments about equalling the outer. Anthers opening lengthwise. Stigmas 3, linear, or stigma single. =33. Haemodoraceae.=