A Flora of Southern Illinois

Key to Families

Key to Families Section 1: NON-FLOWERING VASCULAR PLANTS: FERNS AND ALLIES 1. Sporangia borne in cones or in axils of leaves 2 2. Cones with one kind of spore . 3 3. Stems leafy throughout; leaves narrow or oval, sessile and pointed . . 1. Lycopodiaceae 3. Stems not leafy throughout; leaves, when present, whorled; stems grooved, jointed, and hollow . . 4. Equisetaceae 2. Cones with two kinds of spores, these borne in different sporangia of the same cone; cones somewhat 4-angled; low growing plants . . 2. Selaginellaceae 1. Sporangia not as in 1 above . 4 4. Aquatics (in water or some phase of growth in water) . 5 5. Free floaters; leaves usually two-lobed; sporocarps in pairs beneath the stem . . g. Salviniaceae 5. Plants anchored, usually growing in shallow water or wet wil 6 6. Leaves quadrifoliolate, long-stalked; sporocarps oval, hard coated, and containing two kinds of spores . 10. Marsileaceae 6. Leaves awl-like, tufted, from a dark corm-like stem; sporangia at base of leaves with two kinds of spores, each kind borne in a different sporangium . 3. Isoetaceae 4. Terrestrial forms 7 7. Plants of delicate nature, the fronds membranaceoustranslucent , growing upon lichens and wet, shaded cave 16 KEY TO FAMILIES walls or seeping rocky overhangs. 7. Hymenophyllaceae 7. Plants of less delicate nature, except in winter rosettes and juvenile stages of some species . 8 8. Fertile leaves at the middle of the frond . . Osmunda claytoniana in 6. Osmundaceae 8. Fertile leaves not at middle of frond. 9 9. Sporangia globular and in 2 rows 10 10. Sporangia on a stalked terminal spike; one or more sterile blades present . 5. Ophioglossaceae 10. Sporangia on a terminal upright contracted panicle. 11 11. Rachis of sterile leaves winged . Onoclea in 8. Polypodiaceae 11. Rachis of sterile leaves not winged Botrychium in 5. Ophioglossaceae 9. Sporangia not globular and not in 2 rows . 12 12. Stipes of leaves winged at base; fertile apical pinnae contracted into an upright panicle . 6. Osmundaceae 12. Stipes not winged at base; sporangia in sori on underneath side of leaves or on the margins . . 8. Polypodiaceae Section 2: CLIMBING OR TRAILING VINES OR PARASITES, SAPROPHYTES, OR CACTI I. Plants parasitic, saprophytic or with thick or succulent stems with no leaves, or leaves reduced to spines . 2 2. Plants not parasitic or saprophytic, but with succulent jointed stems and no leaves, or leaves reduced to spines . 103. Cactaceae 2. Plants parasitic or saprophytic. 3 3. Saprophytic plants 4 4. Plants whitish, waxy; ovary superior . 113. Ericaceae 4. Plants not whitish; flowers irregular, ovary inferior . 31. Orchidaceae 3. Parasitic plants . 5 5. Parasitic upon roots or stem branches, not twining 6 6. Plants parasitic upon roots . 7 KEY TO FAMILIES 7. Colorless plants; stamens 4, alternate with corolla lobes . 133. Orobanchaceae 7. Green plants; flowers creamy white; stamens 4, opposite corolla lobes . Comandra in 41. Santalaceae 6. Plants parasitic upon stem branches . . 42. Loranthaceae 5. Plants twining or climbing without tendrils . . 123. Convolvulaceae 1. Plants not parasitic, saprophytic or with thick or succulent stems 17 with no leaves, or leaves reduced to spines . 8 B. Plants climbing by means of tendrils . 9 g. Plants with opposite or whorled leaves 134. Bignoniaceae g. Plants with alternate leaves 10 10. Leaves simple . 11 11. Stems woody 93. Vitaceae 11. Stems herbaceous 12 12. Throat of flower unfringed; fruit a pepo or berry . . 105. Cucurbitaceae 12. Throat of flower fringed; fruit a berry 102. Passifloraceae 10. Leaves compound 13 13. Fruit an inflated capsule; leaves biternate . 91. Sapindaceae 13. Fruit a berry; leaves palmately compound . B. Plants climbing without tendrils 14- Plants with compound leaves 15. Leaves alternate 16. Leaves trifoliolate 93. Vitaceae 17. Plants with woody stems; aerial roots; poison to the skin. 87. Anacardiaceae 17. Plants with herbaceous stems; no aerial roots . . 75. Leguminosae 16. Leaves pinnately compound, with five leaflets . 75. Leguminosae 14 15 16 17 15. Leaves opposite 18 lB. Leaves pinnately compound; plants climbing by aerial roots Campsis in 134. Bignoniaceae lB. Leaves pinnately compound or ternate; numerous stamens; no aerial roots present Clematis in 55. Ranunculaceae 14. Plants with simple leaves 19 19. Leaves alternate 20 18 KEY TO FAMILIES 20. Plants monocotyledonous 21 21. Leaves thin, not waxy, cordate at base; fruit a valved capsule . . 28. Dioscoreaceae 21. Leaves heavy, waxy, entire or lobed at base; fruit a berry . . Smilax in 27. Liliaceae 20. Plants dicotyledonous 22 22. Petals united . 23 23. Flowers...