GARDEN FLOWERS. 285 



from P. Bentinckianum, inguinans, zonale, and others of the 

 same character. 



PENNISETUM. [Gramineae.] A family of ornamental 

 grasses, succeeding in any soil from spring-sown seeds. 



P. villosum (hairy). ; hardy annual ; apetalous ; Brazil. 



PENTHORUM. [Crassulaceae.] Hardy succulent-leaved per- 

 ennials. Common soil. Increased by division. 



P. sedoides (sedum-like) ; hardy perennial ; I foot ; flowers 

 yellow, in July ; North America ; 1768. 



PENTSTEMON. [Scrophularineae.] A large genus of hardy 

 or half-hardy herbaceous perennials, sometimes sub-shrubby ; 

 among the most ornamental of summer-flowering plants. 

 The best kinds for the flower-garden are the varieties of P. 

 Hartwegii, often called gentianoides, which is sub-shrubby, 

 propagates freely by cuttings, and blooms most profusely 

 from August onwards till severe frost occurs. It should be 

 wintered in cold frames, and planted out in spring. They 

 may all be propagated by seeds or cuttings, less freely by 

 division, according to their peculiar habits of growth ; and 

 require to be planted in a moderately rich light loamy soil 

 to attain their full beauty, which is very considerable. Most 

 of those marked half-hardy perennials which are not sub- 

 shrubby, survive over winters, in favorable situations, and 

 protected against excessive wet. It is, however, safer to 

 shelter them in cold frames. They also survive better where 

 there is a keen pure air. 



P. atropurpureus (dark-purple) ; half-hardy sub-shrubby pe- 

 rennial ; 2 feet ; flowers deep rose-purple, in July ; Mexico ; 

 1827. P. azureus (azure) ; half-hardy perennial ; 2 feet; flowers 

 blue, in June ; Mexico ; 1848. P. baccharifolius (baccharis- 

 leaved) ; half-hardy perennial, or perhaps biennial; 18 inches; 

 flowers scarlet, in August ; Texas ; 1851. P. barbatus (bearded) ; 

 hardy perennial ; 3 feet ; flowers light scarlet, in July ; Mexico ; 



