IDENTIFICATION 

  The authority who first described the C. Major was Thomas Walter (1740-1789).  He was a British American botanist who moved to South Carolina in 1768(Rembert 1980).  He discovered and described many plants in his book, Flora Caroliniana, one of which was the C. Major.  A great many of the plants described in his book were contained in his herbarium.  When Walter died his herbarium was eventually passed down to the British Museum of Natural History in London in 1863.  That is were it remains today(Stafleu 1967).

Species Identification Key (Radford 1968)

Stem leaves all alternate.

    One to several stem leaves lobed basally..................................................C. falcata.

    Stem leaves unlobed.

        Basal leaves absent; leaves uniformly reduced upward.........................C.helianthoides

       Basal leaves present at flowering; leaves abruptly reduced upward.

            Basal leaves less than 7 cm long and less than 1.5 cm wide................C. angustifolia

            Basal leaves usually more than 7 cm long, or shorter and more than 1.5 cm wide.

                                                                                                    ................C. gladiata.

Stem leaves opposite (often appearing whorled because of deep dissection).

    Leaves not lobed or dissected.

        Leaves coarsely serrate........................................................................C. latifolia.

        Leaves entire.

            Leaves thick, less than 1.5 cm wide and 8 cm long............................C. angustifolia.

            Leaves thin, more than 1.5 cm wide and 8 cm long.

                Six or more internodes exceeding 1 cm long below the branching of the stem; plant                          caulescent............................................................................C. pubescens.

                Four or fewer internodes exceeding 1 cm long below the branching of the stem; plant                          more or less scapose.

                    Leaves less than 2x as long as wide; plant stoloniferous.............C. auriculata

                    Leaves more than 3x as long as wide; plant not stoloniferous......C. lanceolata.

    Leaves deeply lobed or dissected.

                Leaves sessile, appearing whorled.

                    Leaf divisions more than 3 mm wide, or less and the lateral segments more

                            than 4 cm long....................................................................C. major

                    Leaf divisions less than 2mm wide. lateral segments less than

                            3.5 cm long........................................................................C. verticillata

                Leaves petioled, not appearing whorled.

                    Rays with a red mark at base, rarely all red or yellow; plant annual.

                        Outer bracts 3 mm or less long; netlets about 2x as long as broad.

                            Nutlets wingless..................................................................C.tinctoria.

                            Nutlets winged...... .............................................................C. cardaminefolia

                        Outer bracts 4 mm or more long; nutlets about as broad as long....C.basalis.

                    Rays yellow without a red mark at base; plant perennial.

                        Ten or more internodes exceeding 2 cm long; lateral veins of leaf segments                                  divergent from midrib......................................................C. tripteris

                        Eight or fewer internodes exceeding 2 cm long; lateral veins of leaf segments, at                                  least the lower ones, more or less parallel to midrib.

                            Plant stoloniferous; 3 or fewer internodes exceeding 2 cm long...C. auriculata.

                            Plant not stoloniferous: usually more than 3 internodes exceeding 2 cm long.

                                Unlobed blade or terminal lobe of lower leaves less than 4x as long as                                          wide.......................................................................C. pubescens.

.                                 Unlobed blade or terminal lobe of lower leaves more than 4x as long as                                          wide.

                                      Flowering peduncles usually more than 15 cm long; leaves chiefly basal,                                                  much reduced upward.....................................C. lanceolata

                                      Flowering peduncles usually less than 15 cm long; leaves few at base,                                                  slightly reduced upward....................................C. grandiflora.           

    

Back to the Home Page