What is inflorescence and its types

  INFLORESCENCE

All angiosperms (i.e flowering plants) bears one or more flowers and their arrangements differs from one flowering plants to another. Some plants might have their flowers occuring singly while some in a clustered form, some have theirs directly attached to the peduncle while others attached to a pedicel( which is attached to the peduncle).

NOTE: Both pedicel and peduncle are stalk but differs in the sense that;

PEDICEL is the stalk of a flower, it is directly attached to a single flower

PEDUNCLE is also a stalk but holds different numbers of pedicels.

Now, INFLORESCENCE is the arrangement of flowers on a particular plant( i.e the mode in which flowers are arranged on an axis(peduncle)). With this there are several ways in which flowers are arranged, which are;

• SPIKE FLOWER: This has its flowers developed/ attached directly to the stem(PEDUNCLE). The do not possess the pedicel, e.g., wheat, barley, sorghum, lavender, e.t.c.

Fig1: Diagram of a spike flower

• RACEME: In RACEME, each flower is attached to a short pedicel then the pedicel is further attached to the peduncle, e.g., mustard, snapdragon, alfalfa, e.t.c.

Fig 2: Diagram of a raceme flower

• PANICLE: This is a branched raceme, it contains a cluster of flowers. When you notice a plant, which on its peduncle different numbers of further branched pedicels are attached to it, it is a panicle mode of arrangement, e.g., cashew, yucca, e.t.c.

Fig3: diagram of a panicle flower

 

Note; Raceme posseses unbranched pedicels while panicle possesses branched pedicels.

• UMBEL: An inflorescence is called umbel when all the pedicels carrying its flower originate from a single point on a particular peduncle, e.g., carrot

Fig4: Diagram of an umbel flower

• CORYMB: Here, each flower with its own pedicel is attached to the peduncle at different points in such a way that the length of each pedicel increases while moving down the peduncle, e.g., hawthorns, norwaymaple, Rowan's, e.t.c.

Note: for corymb, all flowers might be of the same level at the top to form a flat shape, or the levels of the flowers might slightly differ at the top to form a convex shape. 

• SPADIX: This differs from spike because the flower(modified spike) is enclosed in a large and often bright coloured bracts, called SPATHE. Spadix can be found in only monocotyledonous plants like Araceae

Fig6: picture of a spadix flower