st, and then rest the plants in cool and dry
conditions.

_A. africana_ is not only most commonly grown, but it is one of the
finest species. Others, some of which are mere varieties of _A.
africana_, are _A. confusa_, _A. gigantea_, _A. nilotica_, and _A.
congoensis_.

~Arachnanthe.~--This is a small genus of warm-house plants possessing
extraordinary habits, and including the Bornean _A. Lowii_ (_Vanda
Lowii_), a very strong-growing species which bears drooping racemes of
greenish-white flowers barred with red. The two basal blooms are
dissimilar or dimorphic both in shape and colour, being tawny yellow
spotted with purple. The plants should be grown in pots or baskets as
Aerides. Other species are _A. Cathcartii_ (Himalaya) and _A.
moschifera_ (Malaya). _A. Cathcartii_ will thrive in the intermediate
house.

~Barkeria.~--The Barkerias form a section of Epidendrums. They should be
grown in baskets or suspending pans in the cool intermediate house. They
require a dry and cool resting period.

~Bartholina.~--The Bartholinas are dwarf, terrestrial Orchids of South
Africa. They should be potted in loam, peat, and sand, and cultivated on
a greenhouse shelf. Rest dry and cool. _B. pectinata_ is the only
species in gardens.

~Batemannia~ and ~Bollea~. _See_ ~Zygopetalum~.

~Bifrenaria.~--Pot these as recommended for epiphytal Orchids, and grow
them in the intermediate house. _B. Harrisoniae_ is the finest species.
Others worthy of cultivation are _B. aurantiaca_, _B. bicornaria_, _B.
inodora_, _B. tyrianthina_, and _B. vitellina_.

~Brassia.~--The Brassias are epiphytal Orchids of South America, and may
be grown in the intermediate house. The most familiar species are _B.
brachiata_, _B. caudata_, _B. Lawrenceana_, and _B. verrucosa_.

~Broughtonia.~--_B. sanguinea_ is a pretty, crimson-flowered species from
Jamaica. _B. lilacina_ is also a fine species, though rarely seen in
gardens. Broughtonias should be grown on bare rafts suspended in the
warm or intermediate house.

~Brassavola.~--A small genus with white, fragrant flowers. _B. Digbyana_,
a species with large, fringed-lipped flowers, has been much used by the
hybridist. Brassavolas may be grown with the Cattleyas.

~Bulbophyllum.~--A widely distributed genus which may be divided into two
sections--the deciduous, chiefly Burmese, requiring a dry resting
season; and the evergreen, which should not be strictly dried off. All
the species thrive in a warm, inte