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Group 9: Herbaceous angiosperms with superior ovaries, actinomorphic flowers, connate petals, and a solitary carpel or 2 or more connate carpels
See list of 17 families in this group-
1b. Plants autotrophic, without haustoria, with chlorophyll (without chlorophyll in Pterospora); stems, when present, upright or twining, usually green for some period during the growing season, with foliaceous leaves (scale-like in Bartonia and Pterospora)
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2a. Depressed, pulvinate [Fig. 603], evergreen, alpine herbs of elevation exceeding 1000 meters; inflorescence a solitary, peduncled flower (in part)
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2b. Plants of various habit, but commonly upright or vining, with deciduous leaves, of lower elevation habitats; inflorescence various, but commonly composed of more than 1 flower
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3b. Leaves borne on a stem (all basal in Limosella, Menyanthes, and Primula); calyx and/or corolla evident, at least 1 of which is petaloid, usually 4- or 5-merous
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4a. Plants often with milky latex; carpels connate at the summit only, with a common stigma; fruit a pair of follicles
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4b. Plants with watery sap; carpels connate throughout or only in the basal portion; fruit an achene, berry, schizocarp, capsule, or pyxis
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5a. Leaves with sheathing stipules (i.e., ocreae) [Fig. 793]; pedicels of the flowers subtended by sheathing bracteoles (i.e., ocreolae); perianth mostly monochlamydeous, composed of ± petaloid tepals; fruit an achene (in part)
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5b. Leaves without sheathing stipules; pedicels without sheathing bracteoles; perianth dichlamydeous; fruit otherwise
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6a. Stems prostrate, emitting at nodes a tuft of 5–10 narrow leaves and 1 or more, 1-flowered peduncles; plants of tidal shores (in part)
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6b. Stems upright or vining, the leaves normally 1 or 2 from a node, sometimes more; inflorescence various, usually with more than 1 flower; plants not of tidal shores (of coastal shorelines in Mertensia maritima and Heliotropium)
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7a. Plants aquatic, with densely crowded, dissected leaves; inflorescence an umbel or raceme, the peduncle and axis of each individual raceme inflated and hollow, constricted at the nodes and bearing a whorl of flowers [Fig. 806] (in part)
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7b. Plants aquatic or terrestrial, the leaves not both densely crowded and dissected; inflorescence without an inflated peduncle and axis
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8a. Foliage leaves opposite or whorled
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9a. Carpels 2, each carpel lobed, often evidently so, therefore, the gynoecium appearing to be composed of 4 carpels, separating at maturity into 4 half-carpellate segments; fruit a schizocarp; flowers with 4 stamens (5 in Boraginaceae); stems quadrangular (terete or angled in Boraginaceae)
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10b. Inflorescence not appearing as a coiled raceme [Figs. 695,700,927]; flowers with 4 stamens; stems quadrangular
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11a. Style usually with an inconspicuous stigma; carpels evidently lobed; inflorescence mixed (i.e., thyrsoid), with cymose lateral branches, these usually arranged in dense verticillasters of flowers, ovules attached to lateral partitions and not the carpel margins [Figs. 926,927]; plants with mint-, pennyroyal-, or citrus-scented foliage (in part)
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9b. Carpels 1–3, not separating at maturity; fruit a capsule or pyxis; flowers with 4–7 stamens; stems mostly terete or angled
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12a. Stamens antepetalous [Fig. 729]; ovary with 1 stigma; placentation free-central (in part)
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12b. Stamens antesepalous; ovary usually with a 2- or 3-lobed stigma; placentation parietal or axile
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13a. Gynoecium with 3 carpels and 3 stigmas; placentation axile; calyx with scarious intervals between the green, longitudinal ribs (in part)
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13b. Gynoecium with 2 carpels and 2 stigmas; placentation parietal; calyx without scarious intervals between longitudinal ribs
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14a. Leaf blades entire; capsule dehiscence septicidal; surface of vegetative organs ± glabrous (though the margins sometimes with cilia) (in part)
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14b. Leaf blades pinnately lobed; capsule dehiscence loculicidal; surface of at least some vegetative parts pubescent (in part)
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8b. Foliage leaves alternate or all basal (appearing opposite in some Solanaceae due to forking of the stem)
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15b. Inflorescence otherwise; fruit a capsule, pyxis, or berry (the berry sometimes dry in the Solanaceae)
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16a. Flowers with 10 stamens and 5 carpels; stipitate-glandular, mycoparasitic herbs lacking chlorophyll (in part)
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16b. Flowers with 4 or 5 stamens and 2 or 3 carpels; autotrophic herbs (except Bartonia), with or without stipitate glands
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17a. Leaves reduced to scales on the stem [Fig. 664]; flowers 2.5–4 mm long (in part)
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17b. Leaves foliaceous, not scale-like; flowers longer
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18b. Plants terrestrial; the leaves neither floating nor with 3 fleshy leaflets
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19a. Stamens antepetalous; placentation free-central
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20a. Leaves confined to the base of the stem; corolla ± salverform (in part)
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20b. Leaves borne on the stem; corolla ± rotate [Fig. 729] (in part)
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19b. Stamens antesepalous; placentation basal, parietal, or axile
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21a. Ovary with 4 or 6 ovules; fruit a 4- or 6-seeded capsule; plants climbing or trailing (twining only at the tip in Calystegia spithamaea) (in part)
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21b. Ovary usually with more than 6 ovules; fruit usually a many-seeded capsule, berry, or pyxis; plants upright (climbing or trailing in Solanum dulcamara)
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22a. Gynoecium composed of 3 carpels (2 in Navarretia); calyx with scarious intervals between the green, longitudinal ribs (calyx of uniform texture in Collomia); fruit a 3-valved capsule (2-valved in Navarretia) (in part)
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22b. Gynoecium composed of 2 carpels (3–5 in Nicandra); calyx of ± uniform texture; fruit a berry, 2-valved capsule, or pyxis
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23a. Stamens each flanked by a pair of small scales; fruit a loculicidal capsule dehiscing by 2 valves (in part)
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23b. Stamens without associated scales; fruit usually a septicidal capsule opening by 2–4 valves, berry, or pyxis
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24a. Fruit an unarmed capsule; anthers with 1 locule, opening by a single, transverse, distal slit; inflorescence a raceme or panicle (in part)
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24b. Fruit a berry, prickly capsule, or pyxis; anthers with 2 locules, opening by a pair of pores or longitudinal slits; inflorescence of solitary flowers in the axils of leaves or cymose (note: the cymes sometimes appear raceme- or panicle-like) (in part)
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Each photo represents one family in this group.