CHARACTERISTICS OF SEEDS. 667 



and flat ; it broadens out at one end into a spatula-like wing ; 

 it is a fugitive samara, and may be blown off by dry east 

 winds immediately after ripening, or later, in winter, by 

 westerly winds. The seed of Maples (Acer) is a nut with a 

 long stiff wing at one end ; the seeds are united at their 

 bases ; they are blown from the trees by dry winds. The 

 seed of Hornbeams (Carpinus) is a hard nut, surrounded 

 by a tri-partite scale, and therefore winged ; at first the seeds 

 are removed from trees by the wind, later on by their own 

 weight. The seeds of Limes (Til in) are nuts, their stalks 

 being united to a stiff, scale- leaf, which renders them fugitive, 

 when the wind is strong. 



In Birches (Betula), the little seeds with winged borders 

 are samaras, attached with alternate tri-partite scales in cat- 

 kins or cones, the segments of which fall (white birches), or 

 the cones open (yellow birches), so that the seeds are released. 

 They are blown to great distances by the wind. In Alders 

 (Alnus), the scales of the cones are lignified and hard; they 

 split when dry, and the small flat and scarcely fugitive seeds 

 fall out. 



In Willows (Salir) and Poplars (frqmlus), the hairy seeds 

 are formed in a capsule, which bursts when ripe, so that the 

 very fugitive seeds escape. In Cherry-trees (Priuius), species 

 of Pyrus [such as /'. Aria, whitebeam ; P. torinin(ilis t wild 

 service-tree ; P. AncujHiria, rowan ; P. S<>r1>u-s, the true service- 

 tree, and the wild pear, medlar, and crab-apple tree. Tr.] , 

 the seeds are surrounded by a fleshy fruit ; after the fruit has 

 fallen, it decays and sets free the seed. The same is true for 

 hawthorn seed (Crata<'<jns). 



Sweet- chestnut (Castanea) has a large seed, that is sur- 

 rounded by a spiny cupula ; either the entire fruit falls when 

 ripe, or the seeds fall from the husk ; the nuts of species of 

 Walnut and Hickory (Juylans and Ilicoria) are surrounded 

 by green husks, which open on ripening. 



The seeds of Papilionaceae (Itolinia, Glcditsia, etc.) are 

 enclosed in a pod ; when this opens, the seeds fall to the 

 ground, or the pods may fall with the seeds in them. 

 . The seeds of Spruces (Picea) are formed in the axils of the 

 scales of pendent cones ; a few months after ripening the 



