HARDY HERBACEOUS PERENNIALS. 



369 



Parnassia (Grass of Parnassus). — Bog plants of great 

 beauty. The flowers are white or yellow, with five stami- 

 nodes on the inner side of the petals bearing globular- 

 headed filaments. P.palustris is one of the most beautiful 



Fig. 454.— Parnassia palustris. 



of our native plants. P. nubicola is useful for pot culti- 

 vation. P.fimbriata has pretty fringed petals. All grow 

 in moist peat soil. 



P. jimbriata. White, fringed petals, 9 inches. North America. 

 P. nubicola. Large white, 9 to 12 inches. Himalaya. 

 P. palustris (fig. 454). White, 9 to 12 inches. Northern Hemi- 

 sphere. 



Pentstemon. — Late summer and autumn flowering 

 plants, with handsome tubular flowers. Besides the 

 popular hybrid forms there are several species and varie- 

 ties well worth a place in the mixed border. They grow 

 freely in any good soil, but a sandy loam, to which well- 

 rotted manure has been added, suits them best. Good 

 drainage is another essential, for they more often succumb 

 owing to the lack of it than to cold. In some localities 

 they are not hardy, and for the winter should be lifted 

 and stored in a cold frame, or cuttings taken in the 

 summer. Propagation by seeds, cuttings, or division. 

 (See also special chapter.) 



P. barbatus. Coral-red, 3 feet. West United States. 



P. campanulatus. Blue, 18 inches. Mexico. 



P. glaber. Light to dark blue, 1 foot. West United States. 



P. humilis (fig. 455). Blue-purple, 8 inches. Rocky Mountains. 



P. ovatus. Purplish-blue, 3 feet. North-west America. 



P. Scouleri. Lilac-blue, 2 to 3 feet. North America. 



Phlox. — Summer and autumn flowering border plants. 

 The dwarf kinds are suitable for the rockery. There 

 are numerous named varieties of P. suffruticosa and P. 

 decussata, which include all shades of colours. The 

 varieties of the first-named are somewhat dwarfer, and 

 flower earlier than those of P. decussata, which come 

 into flower in July and continue into September, carry- 

 ing large heads of bloom 2 or 3 feet high. They are 

 subject to a fungous disease identical with that which 

 attacks Pseonies, and probably due to the same cause, 

 Vol. T. 



viz. excessive manure. The trailing dwarf kinds are 

 ideal rock plants. They succeed well in ordinary soil, 

 and should be propagated by cuttings under glass in 

 sandy loam. (See also special chapter. ) 



P. amozna. Bright-rose, 4 inches. North America. 

 P. divaricata. Soft-blue, 1 foot. North America. 



„ var. alba. White. 



P. lilacina. Mauve, 6 inches. North America. 

 P. ovata. Large deep-rose, 1 foot. North America. 

 P. reptans. Deep-rose, 6 inches. North America. 

 P. setacea. Rose, 6 inches. 

 P. subulata. Rose-pink, 6 inches. United States. 



Phygelius capensis, allied to Pentstemon, is a hand- 

 some border plant 3 to 6 feet high, with spikes of bright- 

 scarlet tubular flowers in autumn. It succeeds in a sunny 

 position in ordinary garden soil, though it thrives better 

 on a border under a wall. It forms a large shrub in 

 south Cornwall, where it is sometimes trained against the 

 walls of houses. Increased by portions of the root-stock. 

 It is a native of South Africa. 



Physalis. — Ornamental plants of the Potato family, 

 with perennial underground stems, annual upright shoots, 

 bearing light-green leaves, small white flowers, and large 

 bladdery bright -scarlet fruits. P. Franchetti is the best 

 of the genus, being larger than P. Aikekmgi, the older 

 species, both in leaves and fruit, the inflated calyces of 

 the former being quite 3 inches in length and of a very- 

 bright orange-red. A preserve is made of the fruits. A 



Fig. 455.— Pentstemon humilis. 



light warm soil in a sunny position suits them. Propaga- 

 tion by division or seeds. 



P. Alkekengi. Bright-orange fruits, U foot. Europe. 

 P. Franchetti (fig. 456). Bright-orange fruits, larger than the 

 first-named. 1 to 3 feet. Japan. 



Physostegia. — Summer-flowering plants, allied to 

 Dracocephalum, with pretty erect spikes of pinkish and 

 white flowers. They thrive in the ordinary border, and 

 may be increased in spring by division. 



P. virginiana. Pink, 2 feet. North America. 



,, var. alba. A good variety. White. 



„ var. imbricata. Pink. 4 feet. 



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