36 AN INTRODUCTION 



lowing properties. 1. A common receptacle divid- 

 ed into peduncles in the manner above-mentioned, 

 whether the umbel produced be plane, flat ; convex, 

 rounding, or concave, hollow. 2. A gennen un- 

 der the corolla. 3. Five distinct stamina that are de- 

 ciduous 4 A bifid pistillum. 5. Two seedevjoined 

 at their summits. 



A Radiate umbel is when the marginal petals are 

 longer than those of the disk, as in Tordylium, C'auca- 

 lis, (Joriandrurn, Ammi, and some species of Hera- 

 cleum ; an umbel may vary also in having the flowers 

 of the margin differing in sex from those of the disk, 

 as in Astrantia,Caucalis,Artedia,Oenanthe and Scan- 

 dix. The mvolucrurn varies, in being either tetra- 

 phyllous, of four leaves, as in Hydrocotyle, Sison and 

 Cuminum ; pent aphyllous, of five, as in Bupleurum, 

 Scandix and Bubon ; kept aphyllous, of seven, as in 

 Ligusticum : decaphyllous, of ten, as in Artedia : 

 with the partial involucrum dimidiate, halved, going 

 but half round, as in Aethusa, Coriandrum, and Sani- 

 cula : or caducous, falling oft', as in Ferula and He- 

 racleum. 



4. A CYMOSE flower, is an" aggregate one, of many 

 florets, placed on a receptacle upon fastigiate pe- 

 duncles, the primary ones of which issue from the 

 same center as in an umbel: but the secondary, or 

 partial ones, lie dispersed without oraer : which cir- 

 cumstance distinguishes the cymafrom the umbel, as 

 in Opulus, Ophiorrhiza, and the species of Cornus 

 called Virga sangumea, or bloody-rod 



5 An AMENTACEOUS aggregate flower has a fili- 

 form, thread-shaped, receptacle, along which are dis- 

 posed amentaceous squamae, scales that form an amen- 

 tum or catkin, as in Xanthium, Ambrosia, Parthe- 

 nia, Iva, Alnus, Betula, Salix, Populus, Corylus, 

 Carpinus, Juglans, Fagus, Quercus, Liquid ambar, 

 Cynomorion, Ficus, Dorstenia, Parietaria, Urtica, 

 Pinus, Abies, Cupressus, Thuya, Juniperus, Taxus 

 and Ephedra. 



