dd) Leaves without stipules; herbs sometimes slightly woody at the base; ovary 1-celled. =Urticaceæ= aa) Calyx always present: b) Moss-like or hepaticiform aquatic herbs with minute flowers; ovules 2 or more in a 1-celled ovary. =Podostemonaceæ= bb) Above characters not associated: c) Leaves opposite or verticillate, never all radical: d) Leaves stipulate: e) Flowers hermaphrodite: f) Herbs, sometimes slightly woody at the base; leaves mostly pinnate. =Zygophyllaceæ= ff) Herbs with simple leaves. =Illecebraceæ= fff) Trees or shrubs with reduced flowers; leaves simple. =Ulmaceæ= ee) Flowers unisexual: f) Ovary 2- or more-celled, often deeply lobed; seeds usually with a distinct caruncle. =Euphorbiaceæ= ff) Ovary 1-celled; ovary usually not lobed: g) Ovule erect: h) Filaments inflexed; mostly herbaceous with fibrous stems; juice not milky. =Urticaceæ= hh) Filaments not inflexed; mostly trees and shrubs, rarely herbs; juice mostly milky, the flowers often minute and arranged on or inside an enlarged receptacle. =Moraceæ= gg) Ovule pendulous: h) Not aquatic: i) Filaments not inflexed in bud: j) Fruit a drupe; flowers monœcious or subdiœcious. =Ulmaceæ= jj) Fruit a small dry achene; flowers diœcious. =Cannabinaceæ= ii) Filaments erect or inflexed in bud. =Moraceæ= hh) Aquatic herb with verticillate divided leaves. =Ceratophyllaceæ= dd) Leaves exstipulate: e) Flowers unisexual; ovary usually 2- or more celled; seeds usually with a distinct caruncle. =Euphorbiaceæ= ee) Flowers hermaphrodite; ovary 1-celled: f) Stamens involute in bud; calyx more or less herbaceous, often long and tubular, mostly covered with sticky glands. =Nyctaginaceæ= ff) Stamens erect in bud: g) Sepals free or nearly so, calyx more or less dry and scarious: =Amarantaceæ= gg) Sepals more or less united, herbaceous.