Asteraceae Fortnight Part I-Radiate heads: Conyza sp. from Kamrup district, Assam- KD 05 : Attachments (13). 4 posts by 3 authors. I had attached images (1 to 8) in my earlier post where I thought them as Conyza bonariensis. Fortunetly I got hints from ... about C. sumatrensis. Then I searched other specimen grown in different places of the same region and collected them (Image No. 11 - 13). I then dissect the reproductive parts of the the specimen and got the following characters. So please ID the Conyza sp. whether it is C. bonariensis or sumatrensis. Date :10.04..2013 (Images no - 08) & 30.05.13 (Images no. 11-13) Location: Kamrup district Family : Asteraceae Genus & species : C. bonariensis or sumatrensis. (?) Habitat: Grows wild. Habit : Herb, more than 5 feet (more than 150 cm Image No. 11) Inflorescence : Radiate head .6cm (length) & 0.3-0.4 cm (w); bract two serriate, hairy, no long hair at the apex of the bract. Flower : Disc floret few, . 6 cm.; pappus . 4 cm; corolla .5cm, 5 lobed, yellow Ray florets(ligulate) many, .5 cm, ligule not distinct; corolla .4 cm. I had seen all three growing in Kashmir and found some interesting facts. Conyza bonariensis is the earliest to flower in May, continuing into june, has more spreading habit, longer and broader leaves and few larger and nearly ovoid to somewhat broader-based heads narrowing towards top, with no visible rays. C. candensis flowers mostly in June, the plants are erect, delicate, linear with much smaller nearly cylindrical heads with distinct ray florets. the plants are barely taller than 1 m. C. sumatrensis (syn: C. albida) is a much taller and robust plant often reaching 2 m ot more, much more robust, with heads almost as long as C. bonariensis, but more cyllindrical, without evident ray florets. The leaves are broader like C. bonariensis, but perhaps more broader if we take L vs B ratio into consideration. The plant becomes prominent August onwards and flowers in August to October in Kashmir and Chakrata where I saw it. |
# Species- Seed plants (families) > A---L (families & genera) > Ar > Asteraceae (Compositae) > Asteroideae > Astereae > Conyza > Conyza species >