DEVELOPMENT OF PLANTS 



403 



sporophylls arranged in a compact inflorescence that assumes a 

 spike-like structure at the tip of the stem. The sporophylls are 

 protected until mature by modified sheathing leaves (Fig. 280, A). 

 Each flower in the upper portion of the spike contains only two 

 or three stamens supported upon a short stalk, which is asso- 

 ciated with hair-like outgrowths (Fig. 280, B), while the lower 

 flowers of the spike bear a single pistil each (Fig. 280, C), which 



Fig. 280. 



Fig. 281. 



Fig. 280. Inflorescence and fruit of Typha: A, inflorescence — b, pro- 

 tecting bracts curving away from the sporophylls; mi, region of staminate 

 flowers; mg, region of pistillate flowers. B, staminate flower consisting of 

 two stamens sessile upon a short stem. C, pistillate flower of one carpel — 

 s, stigma; 0, ovary containing a single ovule. D, appearance of A in the 

 fall — mi, region occupied by staminate flowers; mg, the pistils have increased 

 greatly in size during the ripening of the seed. 



Fig. 281. The mature fruit of Typha: s, remains of the stigma; 0, ovary; 

 p, elongated pedicel bearing numerous hairs. Compare Fig. 280, C. 



consists of a large flat stigma, style and ovary containing a single 

 ovule and supported upon a hairy stalk or pedicel. Note the 



