THE SEED 313 
crustaceous; if smooth and glossy, it is polished, if roughened, it 
may be pitted, furrowed, hairy, reticulate, etc. 
The testa may often present outgrowths or seed appendages 
whose functions are to make the seeds buoyant, whereby they 
may be disseminated by wind currents. Examples of these are 
seen in the Milkweed, which has a tuft of hairs at one end of the 
seed called a Coma, in STROoPHANTHUSs, which has a long bristle- 
like appendage attached to one end of the seed and called an 
Fic. 236.—Appendages of seeds. A, coma (c) on milkweed (Asclepias); B, 
strophiole (st) on bean (Phaseolus) h, hilum, m, micropyle; C, strophiole on Corydalis 
aurea; D, aril on white water-lily (Castalia); E, projecting raphe (r) on pitcher plant 
(Sarracenia purpurea); F, wing on trumpet creeper (Tecoma radicans); G, arillode 
(“mace”) on nutmeg. A, B, and G from nature; C-F, redrawn from Gray. (After 
Gager.) 
Awy, and in the seeds of the Trumpet Creeper and Pines which 
have wings. ‘The excrescence or slightly developed aril at or 
near the hilum of some seeds, as in Castor and Colchicum Seed, is 
called the CARUNCLE or STROPHIOLE. 
The tegmen or inner coat surrounds the nucellus closely and 
is generally soft and delicate. 
A third integument, or accessory seed coat covering the out- 
side of the testa, is occasionally present and is called the Arm. 
or arillus. Examples: Evonymus (succulent) and Cardamom 
(dry). 
