130 



THE FRUIT. 



[l.KS.SON 20. 



thin scales which fall off at the touch ; in the Sneezeweed, of about 



five very thin scales, which look more like a calyx (Figi 294) ; and 



in the Thistle, Aster, Sow-Thistle (Fig. 29o), and hundreds of others, 



it is cut up into a tuft of fine bristles or hairs. This is called the 



Pappus ; — a name which properly means the down like that of the 



Thistle ; but it is applied to all these forms, 



and to every other under which the limb of the i ' \,\\ \ i h, 



calyx of the " compound flowers " appears. In \{ Wntwl 



Lettuce, Dandelion (Fig. 296), and the like, 'M\M 



the achenium as it matures tapers upwards iii'}il| / 



into a slender beak, like a stalk to the pappus. 



350. A Utricle is the same as an achenium, but witk a thin and 

 bladdery loose pericarp ; like that of the Goosefoot or Pigweed 

 (Fig. 297). When ripe it bursts open irregularly to 

 discharge the seed ; or sometimes it opens by a circular 

 line all round, the upper part falling off like a lid ; as in 

 the Amaranth (Fig. 298). 



351. A Caryopsis, or Grain, differs from the last only 

 in the seed adhering to the thin pericarp 

 Ihrougliout, so that fruit and seed are in- 

 corporated into one body ; as in wheat, In- 

 dian corn, and other kinds of grain. 



352. A Nut is a dry and indehiscent fruit, 

 commonly one-celled and one-seedci, with a hard, ci'us- 

 taceous, or bony wall, such as tne cocoanut, hazelnut, 

 chestnut, and the acorn (Fig. 21, 299). Here the 

 involucre, in the form of a cup at the base, is called the Cupule. In 

 the Chestnut it forms the bur ; in the Hazel, a leafy husk. 



FIO. 001. Achenium of Mayweed (no pnpptis). 299. That of Succory (its pappus a shal- 

 low cup). 293. Of Sunflower (pappus of two deciduous scales). 294. Of Sneeze wood (llele- 

 niiim), with its pappus of five scales. 295. Of Sow-Thistle, with its pappus of delicate downy 

 hairs. 29P. Of the Dandelion, its pappus raised on a long beak. 



IG. 297. Utricle of the common Pipweed (Chenopodium album). 



FIG. 298. Utricle (pyxis) of Amaranth, opening all round (circumcissile). 



FIG. 339. Nut (acorn) of tiie Oak, with its cup (or cupule). 



