342 CHOISYA CISTUS 



of three leaflets, but occasionally two or four. Leaflets stalkless, obovate, 

 i|- to 3 ins. long, about one-third as wide; rounded or blunt at the end, 

 tapering to a common point of union at the end of a downy leaf-stalk 

 i to 2 ins. long; when crushed they have a strong, pungent, rather 

 unpleasant odour, and held against the light will be seen to be pitted with 

 numerous oil-glands. Flowers produced in a cluster of axillary corymbs 

 at the end of the shoot, each corymb three- to six-flowered, with a slender, 

 downy stalk 2 to 3 ins. long. Flowers white, i to ij ins. across, with 

 five roundish oval petals ; fragrant like hawthorn. 



This fine evergreen is of interest as being one of the very few shrubs 

 native of Mexico that are hardy near London. It survived practically 

 uninjured the great frosts of Feb. 1895 at Kew, also the trying winter 

 of 1908-9. But for some constitutional reason it is often injured during 

 spells of lesser cold, especially after the New Year. Its normal flowering- 

 time may be considered April and May, but it often produces flowers 

 more 'or less up to September. On a few occasions after a very mild 

 November, I have seen it in full blossom in December. It should have 

 an open but sheltered spot, and the soil may be a rather light loam. It 

 is better to encourage a short, well-ripened growth rather than a thick, 

 sappy one. Cuttings made of half-ripened wood root quickly placed in 

 gentle heat ; those of a little harder wood will take root in a cold frame. 



CISTUS. ROCK ROSE. CISTACE/E. 



A genus of about twenty species, nearly allied to Helianthemum, 

 but differing in having the seed-vessels five- or ten -celled, whilst in 

 Helianthemum they are three - celled. Leaves opposite, evergreen. 

 Flowers of a rose-like appearance, having five broadly wedge-shaped petals 

 and very numerous stamens ; sepals three to five. Seeds numerous. In 

 a wild state the cistuses are found in the Mediterranean region, and are 

 especially abundant in Spain and Portugal. The flowers usually last only 

 a few hours in the morning, never more than a day, but a constant 

 succession of them is maintained during sunny weather, making a fine 

 display in June and July. None of the cistuses are yellow-flowered, but 

 they very frequently have a patch of that colour at the base of each 

 petal. Although the number of true species is comparatively limited, they 

 have -hybridised freely, both in a wild and cultivated state. Some of the 

 best are hybrids, such as cyprius, purpureus, Loreti, and corbariensis. 



Unfortunately the .rock roses with few exceptions are not genuinely 

 hardy. They survive our mild winters, but many succumb in severe or 

 even moderately hard ones. The great frosts of February 1895 killed all 

 the cistuses at Kew except C. laurifolius, C. corbariensis, and C. Loreti. 

 They like a light, well-drained soil, and more than anything a position 

 exposed to full sun, but otherwise sheltered, and something above the 

 surrounding level. They never suffer from drought, and any dry, sunny 

 bank will suit them. A covering of bracken or leafy branches in severe 

 weather is a help, and will often save plants that would otherwise perish. 



Propagation may be effected by seed or by cuttings, the latter being 



