PLANT ORGANS AND ORGANISMS 
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the nearly equal pedicels radiate from it like the rays of an umbrella. 
Many examples of this mode of inflorescence are seen in the family 
Umbelliferce, as indicated by the name, including Anise, Fennel and 
other drug-yielding official plants. 
A Spike is a cluster of flowers, sessile or nearly so, borne on an 
elongated axis. The Mullein and common Plantain afford good 
illustrations. 
The Catkin or Ament resembles the Spike, but differs in that it has 
scaly instead of herbaceous bracts, as the staminate flowers of the 
Oak, Hazel, Willow, Comptonia, etc. 
The Head or Capitulum is like a spike, except that it has the rachis 
shortened, so as to form a compact cluster of sessile flowers, as in the 
Dandelion, Marigold, Clover, and Burdock. 
The Strobile is a compact flower cluster with large scales concealing 
the flowers, as the inflorescence of the Hop. 
The Spadix is a thick, fleshy rachis with flowers closely sessile or 
embedded on it, usually with a spathe or sheathing bract. Example: 
Calla, Acorus Calamus, Arum triphyllum . 
The compound raceme, particularly if irregularly compounded, is 
called a panicle. 
Determinate Inflorescences. — Determinate Anthotaxy is one in 
which the first flower that opens is the terminal one on the axis, the 
other appearing in succession from apex to base or from center to 
margin. The principal varieties are: 
The Solitary Determinate, in which there is a single flower borne 
on the scape, as in the Anemone, or Windflower, and Hydrastis. 
The Cyme, a flower cluster resembling a corymb, except that the 
buds develop from center to circumference. Example: Elder. If 
the cyme be rounded, as in the Snowball, it is a globose cyme. 
A Scorpoid Cyme imitates a raceme, having the flowers pedicelled 
and arranged along a lengthened axis. 
A Glomerule is a cymose inflorescence of any sort which is con- 
densed into a head, as the so-called head of Cornus florida. 
A V erticillaster is a compact, cymose flower cluster which resembles 
a whorl, but really consists of two glomerules situated in the axils 
of opposite leaves. Clusters of this kind are seen in Catnip, Hore- 
hound, Peppermint and other plants of the Labiatce. 
