EPHEDRA FAMILY 79 



Class 2. ANGIOSPERMAE. 



Ovules borne in an enclosed ovary formed by a single sporophyll (carpel) or 

 by several sporophylls united together. Pollination is effected often through the 

 agency of wind or insects (cross-pollination), or less commonly within the flower 

 itself (self-pollination). The pollen-grains after alighting upon the summit of 

 the ovary (stigma) germinate, sending a tube into the tissue, which, upon enter- 

 ing the ovule, effects fertilization by the fusion of the egg cell of the ovule and 

 the spermatozoid of the pollen-tube. 



The angiosperms have been the dominating plants of the world since the Mesozoic Era, and are repre- 

 sented by over 130,000 living species, comprising two distinct sub-classes, as follows: 



Cotyledons 1: stem endogenous; leaves commonly parallel-veined. Sub-class 1. Monocotvledones. 



Cotyledons 2: stem (with rare exceptions) exogenous; leaves commonly net-veined. 



Sub-class 2. Di cotyledon es. 



Sub-class 1. MONOCOTYLEDONES. 



Stem composed of a ground-mass of soft tissue (parenchyma ) in which the 

 bundles of wood-cells are irregularly imbedded ; no distinction into wood, pith and 

 bark. Leaves usually parallel-veined, mostly alternate and entire, commonly 

 sheathing the stem at the base and often with no distinction of blade and petiole. 

 Flowers mostly 3-merous or 6-merous. Embryo with but a single cotyledon, and 

 the first leaves of the germinating plantlet alternate. 



Monocotyledonous plants are first definitely known in Triassic time. They constitute between one-fourth 

 .and one-third of the living angiospermous flora. 



Family 1. TYPHACEAE. 



Cat-tail Family. 



Alarsh or aquatic herbaceous plants with creeping rootstocks, fibrous roots and 

 glabrous erect, terete stems. Leaves linear, flat, ensiform, striate, sheathing at 

 the base. Flowers monoecious, densely crowded in terminal spikes, which are sub- 

 tended by spathaceous, usually fugaceous bracts, and divided at intervals by smaller 

 bracts, which are caducous, the staminate spikes uppermost. Perianth of bristles. 

 Stamens 2-7, the filaments connate. Ovary 1, stipitate, 1-2-celled. Ovules anatro- 

 pous. Styles as many as the cells of the ovary. Mingled among the stamens and 

 pistils are many bristly hairs, and among the pistillate flowers many sterile flowers 

 with clavate tips. Fruit a minute achene. Endosperm copious. 



The family comprises only one genus. 



. 1. TYPHA [Tourn.l L. Sp. PI. 971. 1753. 



Characters of tlie family. (Name ancient.) 



About 10 species, of temperate and tropical regions. Type species, Typha latifolia L. 



Spikes with the pistillate and staminate portions usually contiguous, the former without bractlets; stigmas 

 spatulate or rhomboid; pollen-grains in 4's. 1. T. latifolia. 



Spikes with the pistillate and staminate portions usually distant, the former with bractlets; stigmas linear or 

 oblong-linear; pollen-grains simple. 2. T. angustifolia. 



