HOUSE, THE GENUS IPO MCE A 
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or divided, usually petioled. Flowers solitary on axillary peduncles or in 
cymes, rarely in raceme-like clusters. Sepals 5, membranaceous or rather 
fleshy, sometimes becoming leathery, often herbaceous, closely imbricated, 
sometimes elongated. Corolla funnelform or funnelform-campanulate, 
rarely salverform, the tube often constricted within the calyx, the limb 
usually spreading, the plicse ending at the middle of the margin of each 
lobe, rarely between the lobes. Stamens 5, included, rarely exserted. 
Ovary 2-, 3-, 4- or rarely 5-celled. Styles united. Capsule mostly septi- 
fragally 2-, 3-, 4- or 5-valved, sometimes thick-walled and elongated. Seeds 
glabrous, pubescent or hirsute on the angles, often with a long wool-like 
coma on the dorsal angles. 
Key to the Sections of Ipomoea. > 
Plants erect, stout, perennial, shrubby or tree-like; 
leaf-blades rarely cordate. SECTION I. ORTHIPOMCEA. 
Plants twining, creeping or prostrate, stout or 
slender; leaf-blades often cordate. 
Sepals herbaceous, often elongated and hairy; 
ovary usually 3-celled. SECTION II. PHARBITIS. 
Sepals coriaceous, membranaceous or sub- 
herbaceous; rarely elongated; ovary usu¬ 
ally 2- or 4-celled. Section III. BATATAS 
Key to the Subsections. 
I. ORTHIPOMCEA. 
Shrubby below or with stout, erect or ascending herbaceous 
stems. 
Sepals lanceolate, acuminate; plant silvery. 1. 
Sepals ovate or ovate-oblong, usually obtuse or acute; 
foliage not silvery but often pubescent. 2. 
Arborescent, erect and woody. 3. 
Argyrophyllse. 
Leptophyllse. 
Arborescentes. 
II. PHARBITIS. 
Inflorescence densely capitate or leafy-bracted. 4. Cephalanthae. 
Inflorescence not conspicuously bracted or capitate. 
Ovary typically 3- or 5-celled. 
Outer sepals becoming different from the inner ones, cor¬ 
date or truncate and often conspicuously broadened 
at the base. 5. Heterophyllae. 
Sepals not becoming cordate or truncate nor conspicu¬ 
ously enlarged in fruit. 
