THE MAGNOLIA FAMILY 359 



in figures 159,;? and 271. Somewhat similar expansions serv- 

 ing for protection occur at the base of marsh-marigold leaves; 

 but these, although suggesting stipules, are not regarded as 

 sufficiently developed to deserve the name. The leaves of 

 star-anise, as of the cro\vfoot family, are exdipulate,^ that is, 

 without stipules. Finally, as regards their habit, ^ or general ap- 

 pearance, the tuhp-tree is, as itsname implies, a tree, while the 

 species of magnolia and star-anise are either trees or shrubs. 



The result of our examination thus far is to show that 

 star-anise in several particulars forms a good link connecting 

 the tulip-tree with members of the crowfoot family, and we 

 have not yet found a single feature which will serve to dis- 

 tinguish all of the magnolia family from all of the cro^\'foot 

 family. 



This resemblance will appear still more plainly if we express in 

 formulas the facts observable in our examples. Let us indicate the 

 presence of stipules by an inverted dagger sign, \.; a wing on the 

 pericarp by an inverted interrogation mark, i ; and dorsal dehiscence 

 by ; . We may then write our formulas of Magnolia, Illicium, and 

 Liriodendron ' as shown on pages 404, 405. 



If we added to these examples other magnoliaceous genera we 

 should of course introduce some new variations of structure, but 

 these would afford us no better family characters. A formula 

 typical of the family would stiU be the same as that given Ijelow the 

 three genera mentioned. 



Comparing our magnoliaceous formulas with the ranunculaceous 

 ones we find that while prevailing features differ — so much so 

 indeed as to make it desiralsle to group the plants in separate fam- 

 ilies — the departures from the type in one family often match those 

 of the other. 



There is, however, a general difference, not shown in the 

 figures, which serves to separate the two groups. All mem- 

 bers of the magnolia family have in the leaf-pulp, floral leaves, 

 pith, and other soft parts, minute reservoirs of volatile oil, 

 which are entirely lacking in the crowfoot famih'. These little 

 reservoirs may be seen readily with a hand lens Yjy viewdng 



1 Ex-stip'u-Iate < L. ex, without; stipula, stipule. 



- Hab'it < L. habitus, appearance. 



' The plant formulas referred to in this and succeeding sections, 

 together with the ranunculaceous formulas already given, are grouped 

 on pages 404-427 to facilitate their being compared with one another. 



