Descriptions and Illustrations
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1 Descriptions and Illustrations General Key to Groups of Aquatic and Wetland Dicots 1. Leaves pitcherlike...................................................................................107. Sarraceniaceae* 1. Leaves not pitcherlike, or absent. 2. Plants without chlorophyll........................................................................61. Cuscutaceae 2. Plants with chlorophyll. 3. Leaves reduced to scales ....................................................Bartonia in 69. Gentianaceae 3. Leaves not reduced to scales. 4. Plants aquatic, living in water the entire year.................................................Group 1 4. Plants terrestrial, at least part of the year. 5. Plants with latex..........................................................................................Group 2 5. Plants without latex. 6. Some part of plant prickly or spiny..........................................................Group 3 6. Plants not prickly nor spiny. 7. Plants climbing or twining ..................................................................Group 4 7. Plants erect, ascending, prostrate, or trailing, not climbing nor twining. 8. Plants woody (excluding woody vines that are in Group 4). 9. Leaves opposite or whorled...........................................................Group 5 9. Leaves alternate. 10. Leaves simple, entire, toothed, or lobed ..................................Group 6 10. Leaves compound....................................................................Group 7 8. Plants herbaceous. 11. Leaves all basal or, at most, with one cauline leaf .....................Group 8 11. Leaves cauline (basal leaves may also be present). 12. Leaves, or some of them, whorled ........................................Group 9 12. Leaves opposite or alternate. 13. At least some of the leaves opposite. 14. Leaves simple. 15. Leaves entire........................................................Group 10 15. Leaves toothed or lobed.......................................Group 11 14. Leaves compound.....................................................Group 12 13. All leaves alternate. 16. Leaves simple. 17. Leaves entire .......................................................Group 13 17. Leaves toothed or lobed.......................................Group 14 16. Leaves compound. 18. Leaves trifoliolate or ternate................................Group 15 18. Leaves pinnately or palmately compound. 19. Leaves pinnately compound..........................Group 16 19. Leaves palmately compound .........................Group 17 Group 1. Plants aquatic, living in standing water the entire year. 1. Plants attached to rocks or wood in flowing water..................................97. Podostemaceae* 1. Plants not attached to rocks or wood in flowing water. 2. Some of the leaves deeply divided or compound. 3. Flowers borne together in a solitary, yellow head, each flower sharing a common receptacle ..................................................................................Megalodonta in 45. Asteraceae * Family names marked with an asterisk are included in volume 4. 2 / GENERAL KEY TO GROUPS OF AQUATIC AND WETLAND DICOTS 3. Flowers not crowded, each with its own receptacle. 4. Leaves trifoliolate...................................................Menyanthes in 86. Menyanthaceae 4. Leaves 5- to 9-parted or pinnatisect. 5. Leaves 5- to 9-parted................................................Nasturtium in 50. Brassicaceae 5. Leaves pinnatisect. 6. Underwater structures bearing small bladders; flowers zygomorphic.................. .............................................................................................80. Lentibulariaceae 6. Underwater structures not bearing bladders; flowers actinomorphic. 7. Some or all the flowers unisexual. 8. Calyx (or involucre) 8- to 12-cleft; stamens 10–20; ovary unlobed............... .................................................................................... 57. Ceratophyllaceae 8. Calyx 3- or 4-cleft; stamens 3–8; ovary 2- to 4-lobed.....71. Haloragidaceae 7. All flowers perfect. 9. Pistils 2–several, free, or pistil 1 but deeply 2- to 4-lobed. 10. Sepals 3; petals 3; stamens 3 or 6.................................51. Cabombaceae 10. Sepals 4–5; petals 0, 4, or 5; stamens 3, 4, 8, or numerous. 11. Sepals 5; petals 5; stamens numerous................................................ ..................................................Ranunculus in 102. Ranunculaceae* 11. Sepals 4; petals 0 or 4; stamens 3, 4, or 8............71. Haloragidaceae 9. Pistil 1, unlobed. 12. Sepals 5; petals 5, united at base; stamens 5............................................ ................................................................. Hottonia in 101. Primulaceae* 12. Sepals 4; petals 4, free; stamens 6............. Neobeckia in 50. Brassicaceae 2. Leaves simple, none deeply divided. 13. Leaves with conspicuous sheathing stipules (ocreae) at base ........ 100. Polygonaceae* 13. Leaves without sheathing stipules at base. 14. Flowers unisexual; petals absent. 15. Calyx absent; fruit heart-shaped........................................... 53. Callitrichaceae 15. Sepals 3; fruit ellipsoid..................................Proserpinaca in 71. Haloragidaceae 14. Flowers perfect; perianth, or at least the calyx, present. 16. Leaves peltate. 17. Sepals, petals, and stamens each 5 ....................Hydrocotyle in 39. Apiaceae 17. Sepals, petals, and stamens some number other than 5. 18. Sepals 3–4; petals 3–4; stamens 12–18; leaves up to 6 cm across, covered with a gelatinous material .........................Brasenia in 51. Cabombaceae 18. Sepals and petals indistinguishable, together totaling more than 8 segments ; stamens more than 20; leaves more than 6 cm across, not gelatinous ....................................................................... 89. Nelumbonaceae* 16. Leaves not peltate. 19. Leaves opposite or whorled. 20. Stamen 1; leaves linear...............................................73. Hippuridaceae 20. Stamens 3–5; leaves not linear. 21. Sepals and petals usually 3 each................Elatine in 63. Elatinaceae 21. Sepals and petals (if present) usually 4 or 5 each. 22. Corolla absent ......................................Didiplis in 83. Lythraceae 22. Corolla present. 23. Stamens 2; leaves lanceolate or ovate .................................... .....................................................Justicia in 35. Acanthaceae 23. Stamens 4; leaves more or less orbicular to oblong................ ..........................................Bacopa in 110. Scrophulariaceae* 19. Leaves alternate...