ONAGRACE.E 



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below, and growing to the height of 3 feet or more. 

 The root-leaves have long stalks ; and the other 

 leaves are sessile ; the flowers rising singly in the 

 axils of the latter at the ends of the stem and 

 branches. The flowers are very short-stalked, and 

 have 4 broad bright yellow petals, inserted in the 

 tube of a long narrow calyx, the sepals of which are 

 recurved. They do not expand in bright weather, 

 but only in dull weather, or in the evening, when they 

 unclose with a slight sound after sunset. They only 

 last a day. The root is sometimes used in salad. 

 The Green Humming-bird Hawk-moth (Pterogon 

 Proserpina) was named Sphinx ccnothercz by some 

 Austrian entomologists, because its dark green or 

 grey caterpillar, which has a yellow spot centred 

 with black in place of the usual horn, sometimes 

 feeds on Evening Primrose, though its usual food 

 is Willow-herb. The moth expands about an inch 

 and a half across the wings, which are irregularly 

 dentated on the hindmargin. The forewings are 

 green and the hindwings orange, with a black 

 border. It is found in Southern and South-Central 

 Europe, but not in Britain ; and it is somewhat 



singular that this moth is attached to an American 

 plant, for though it is not found in America, its 

 nearest relationships are with American rather than 

 with European species. The late Mr. H. T. 

 Stainton called this moth "the most beautiful of 

 the Spht'ngina." 



Another interesting plant belonging to the 

 Onagracece is the Enchanter's Nightshade (Circcea 

 lutetiatia), which is found in damp shady places. 

 It has only 2 white petals, more or less suffused 

 with reddish, 2 stamens, and the fruit consists of 

 1 or 2 cells and is set with hooked bristles. The 

 leaves are stalked, opposite, and more or less oval 

 and pointed. 



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Horn Nut — Trapa natans 



(Plate XXXVIII) 



This very curious water-plant is a native of 

 Central and Southern Europe, but does not now 

 grow wild in the British Islands, though it was 

 formerly a British plant, having been found by 

 Mr. Clement Reid in the Pleistocene deposits 



