ANGIOSPERMS. — MONO CO TYLEDOXS. 



435 



probably those found on the inflorescence of many species o'i AUiinn. Hofmeister 

 states that adventitious buds are produced on the roots of Epipactis microphylla ; 

 and the transformation of the tips of the roots into shoots has been observed in 

 Neoltia Nidus avis and Anthurium longifolium. 



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Fig. 360. Colchiciim antictiDiale, the underground portions of a flowering plant. A seen in front aiul from 

 without ; k the tuber, .r' and s" scale-leaves which envelope the flower-stalk, 7i//» its base from which the roots lu proceed. 

 B longitudinal section of the preceding, the plane of section being perpendicular to the paper ; hh a brown skin which 

 covers all the underground parts of the plant, st the stalk of the flower and leaf of the previous year, which is dead and 

 has left only its basal portion swollen into a tuber * as a reservoir of food-material for the new plant just coming into 

 flower ; this plant is a lateral shoot from the base of the tuber k and consists of an axis, from the base of which the roots 

 7v' proceed, while its middle part k' enlarges into a tuber in the following year, the old tuber k disappearing : tlie a.\is 

 bears the sheath-leaves s ^, s" and the foliage-leaves /', /" ; in the axils of the uppermost foliage-leaves are the flowers 

 b, b', and the axis itself tenninates free between them. Tlie foliage leaves are still small at the time of flowering, and 

 appear with the fruits above the ground in the ensuing year ; the portion *' of the axis then swells into the new tuber, 

 on which the axillary bud *" is developed into a new flowering axis, while the sheath of the lowest foliage-leaf is trans- 

 forme 1 into the brown membranous envelope. 



The leaves of Monocotyledons are seldom verlicillate, the foliage leaves of Elodea 

 and the bracts of Alisvia being exceptional in this respect ; their arrangement in two 

 alternating rows, as in the Gramineae, Irideae, Phonnium, Cliria, Typha, etc., is very 

 common, and either prevails over the whole shoot and its secondary shoots, or appears 

 at first and subsequently passes into spiral arrangements which often lead to the 

 formation of rosettes of leaves spreading in every direction, as in Aloe, Agave, Palms, 

 etc. The arrangement with the ^ divergence is much less common, and is found 



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