PHANEROGAMIA 543 



the upper part of each scale marks the place of separation of the leaf-blade. The 

 annual course of development is essentially similar in other bulbous plants. The 

 vegetative period is restricted to a few months, while during the cold or, in the 

 numerous bulbous plants of warm-temperate climates, the dry seasons, the bulb is 

 protected by its subterranean situation. Aloe, a genus of African plants con- 

 taining many species (Fig. 540) may be mentioned as an example of an arborescent 

 member of the Lilieae. 



Dracaena (Fig. 541), an arborescent form which attains a great age and a 

 characteristic appearance, together with the similar genera, Gordyline and Yucca, 

 belong to the Asparageae. To the same sub-family belongs Smilax (Sarsaparilla), 

 a shrubby plant of warmer countries, climbing by the help of tendril-like 

 emergences at the base of the petioles. Other examples are Asparagus with 

 bunches of phylloclades (p. 25) in place of leaves, Convallaria (Fig. 34), 

 Maianthemum, Polygonatum, and Paris quadrifolia (Fig. 542) ; the latter bears 

 whorls of four leaves, sometimes 3-6 leaves. All these plants have creeping rhizomes 

 bearing scale-leaves ; either the apex of this rhizome grows annually into the 

 erect shoot bearing the foliage leaves and inflorescences, while the growth of the 

 rhizome is continued by a lateral branch (Polygonatum, Fig. 23), or the rhizome 

 continues its subterranean growth, the leafy shoots being developed from 

 axillary buds (Paris). 



POISONOUS. Numerous Liliaceae are more or less poisonous, e.g. Lily of the 

 Valley, Tulip, Fritillaria, Colchicum, Vcratrum, Paris. 



OFFICIAL. Colchicum autumnale, seeds and corm ; Schoenocaulon (Sabadilla) 

 officinalis, a bulbous plant with grass-like foliage from mountains of Central 

 America and Venezuela, seeds yield VERATRINUM. Aloe vera, A. chinensis, A. perryi 

 and other species yield ALOES BARBADENSIS and ALOES SOCOTKINA. Urginea scillae 

 yields SQUILL. Smilax ornata, etc., yield SARSAPARILLA. 



Family 3. Amaryllidaceae. Distinguished from Liliaceae by the inferior 

 ovary. Lcucojum (Fig. 543), the Snowdrop (Galanthus) and Narcissus resemble 

 the bulbous Liliaceae in habit. Agave, large plants with succulent leaves from 

 the warmer regions of America, provide fibres. A. mexicana provides the national 

 drink of Mexico (pulque), obtained by fermenting the sap that flows on cutting 

 off the inflorescence. Species of Agave are naturalised in the Mediterranean region 

 but none are native there. 



Family 4. Iridaceae. Distinguished from Liliaceae by their 

 inferior ovary and by the suppression of the inner whorl of the 

 androecium (Fig. 544). The two whorls of the perianth are not 

 always similar. Anthers extrorse. The leaves of the Iridaceae are 

 always sessile ; the underground portion is a tuberous or elongated 

 rhizome, rarely a bulb. Capsule loculicidal. 



Crocus satimis, Saffron (Fig. 545) is a plant which has long been cultivated in 

 the East ; it has a tuberous rhizome and narrow, grass-like leaves. The flowers 

 are sterile unless pollinated with pollen of the wild form. The large stigmas 

 furnish Saffron. Other species are cultivated as ornamental plants. 



Iris, leaves overlapping in two ranks. The leaf-sheath surrounds the thick 

 fleshy rhizome, while the sword-shaped blade stands erect and has its two 

 surfaces alike (Fig. 546). Outer perianth segments bent downwards, inner erect. 

 The three anthers are roofed over by the three, leaf-like styles. In Gladiolus the 

 flowers are dorsiventral and the dissimilarity of the perianth leaves is more 

 marked. 



