VI INTRODUCTION. 



employed it to designate the undivided part of the calyx, when too open to be 

 called a tube. 



I have used the word Phyllaries for the parts in the Compositse which were 

 considered by Linnseus as the leaves of the common calyx, and by later writers 

 as the bracts of an involucrum ; but I wanted the words brads and scales to 

 indicate parts external to this calyx, and the Greek word pliyllarion, signifying a 

 little leaf, seemed to furnish just what I wanted. 



In describing the Compositas, besides introducing the word phyUaries, I have 

 called Crest, that ornament to the seeds which is named down by Smith, and 

 pappus by Hooker ; and I caU the parts of which it is composed, shafts, which 

 may be chaff-like, hair-Uke, or feathery. 



Perhaps the terms compressed and obeompressed, though not introduced by me, 

 may not be familiar to the student. Seeds are said to be compressed when the 

 greatest diameter is in the direction of the rays, from the centre to the circum- 

 ference of a compound flower ; obeompressed, when the greatest diameter is at 

 right angles to that dii-ection. In fig. 18 the seeds are compressed; in fig. 19 

 obeompressed. 



The word fertile is used in this work for flowers containing the pistil but no 

 stamens, and producing seeds. Where from such a flower no seeds are produced, 

 it is called unproductive. Barren flowers have stamens and no complete pistil. 

 Neutral flowers, or florets, have neither stamens nor pistils. Complete flowers 

 have all the essential parts. 



Cyme has been used by modem botanists to denote two very different modes of 

 inflorescence. One is, according to the definition given by Linnseus, an umbel 

 whose rays are ii'regularly subdivided, as in Sambucus, Cornus, &c. ; the other, 

 for an arrangement which is frequent among the CaryophyEacese and in Rosa, 

 where opposite branches spring on each side of the primordial flower, and again 

 from the secondary flowers produced on these branches. The first is indefinite 

 both as to the number of flowers and the order of their expansion. The second 

 is essentially centrifugal, and the number of flowers is typically 3, 7, 15, 31, 

 each increase being one more than the double of the preceding. 



Botanists have used the word Joint, and its corresponding Latin word Articulus, 

 as signifying the point of union of two different parts, or the space between those 

 parts. Por the first I use the term Joining ; and when I say that a leaf is 

 joined to its stalk, or the upper part of an awn or of a stem to the lower, 

 I mean that the parts are not perfectly continuous, but exhibit a distinguish- 

 able point of junction. Joint is used as it is in common speech, when we talk 

 of a joint of meat, &c., for the parts so joined. 



I have used the word Gusset in the Umbellatse, to denote the triangular filling 

 in, in some genera, between the round kernel and its semiround covering. 



