MONOCOTYLEDONEAE 5 



35. Perianth consisting of i — 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 seg- 

 ments 36 



36. Ovules numerous, covering the whole inner surface of the carpels. 



13. Butomaceae. 



Ovules I — 2, rarely more, and then all inserted at the upper suture of the 



carpels 12. Alismataceae. 



37. (15.) Stamen i. Flowers irregular 38 



Stamens 2 — 18. Flowers usually regular. 41 



38. Staminodes small or wanting. Ovary i-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 i-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 i-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 thick- 

 ened 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 



I-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-segmants about equalling 



the outer. Anthers opening lengthwise. Stigmas 3, linear, or stigma 



single 33. Haemodoraceae. 



Leaves scale-like, not green, rarely well-developed and green, but then inner 

 perianth-segments much smaller than the outer or wanting, anthers 

 provided with an enlarged connective and opening transversely, and 

 stigmas 3, short and thick 43. Burmanniaceae. 



45. Ovary incompletely 6 — 15-celled with 6 — 15 stigmas, more rarely completely 



I-celled with 3 stigmas. Perianth consisting of calyx and corolla, more 



