Tetrachondra. | BORAGINACEZ. 473 
‘ 
A remarkable little plant, the systematic position of which is very doubtful. 
It was originally placed in Tillea by Kirk, and no doubt there is considerable 
outward similarity with that genus, although it differs fundamentally in the 
gamopetalous corolla, the 4-lobed ovary, and the simple imbedded style. Prof. 
Oliver, no doubt influenced by the 4-lobed ovary, transferred it to the Bora- 
ginacee, although he points out (‘‘Icones Plantarum,’’ t. 2250) that it departs 
from the characters of the order in the opposite leaves connate at the base, and 
in the albuminous seeds. Dr. Hans Hallier, in an interesting paper printed in 
the ‘‘ Berichten der Deutschen Botanischen Gesellschaft ’’ for 1902, suggests 
that it should be considered an anomalous member of the Scrophularinee, and 
that its nearest ally is the section Pygmea of Veronica. A study of the early 
development of the corolla would probably either prove or disprove this view. 
Orper LIL. CONVOLVULACESA. 
Herbs or shrubs, frequently twining, often with milky juice. 
Leaves alternate, exstipulate, wanting in Cuscuta. Flowers re- 
gular, usually hermaphrodite, axillary, solitary or cymose, often 
large and showy. Calyx inferior, persistent, usually of 5 distinct 
imbricated sepals. Corolla gamopetalous, hypogynous, campanu- 
late or funnel-shaped or rotate, limb shortly or deeply 5-lobed or 
almost entire, often plaited and contorted in bud. Stamens 5, 
inserted on the tube of the corolla and alternate with its lobes; 
anthers oblong, opening lengthwise. Ovary superior, usually sur- 
rounded by an annular disc, 2—4-celled, rarely 1-celled, sometimes 
divided into 2-4 distinct carpels; style single or 2; stigma capitate 
or 2-lobed or branched ; ovules usually 2 in each cell or carpel, 
erect, anatropous. Fruit a 1—4-celled capsule, 2-4-valved or burst- 
ing transversely or irregularly, rarely succulent and indehiscent. 
Seeds erect; albumen scanty or wanting; embryo curved, coty- 
ledons broad, much folded and crumpled (in Cuscuta the embryo is 
spiral and undivided). 
A moderately large order, widely spread over the whole world, but most 
plentiful in warm or tropical climates. Genera 32; species about 800. As a 
rule, the roots abound in a milky and acrid juice, which is often strongly purga- 
tive and used in medicine, as jalap and scammony. In some species the roots 
are inert and edible, as the common sweet potato, so largely cultivated in all warm 
countries. Many species of Ipomea and allied genera are grown for the sake 
of their large and showy flowers. All the New Zealand genera have a wide range. 
* Leafy plants, twining or prostrate. 
+ Corolla plaited. Style single. 
Ovary 2-4-celled. Stigma capitate, or lobes globose -. J. Tromaa. 
Ovary imperfectly 2-celled. Stigmas 2, oblong, flat. 
Bracts large, enclosing the calyx : oe .. 2, CALYSTEGTA. 
Ovary 1-celled. Stigmas 2, linear, flat. Bracts small or 
wanting .. “3 : oe AS .. 3. CONVOLVULUS. 
tt Corolla rotate. Styles 2 
Ovary of 2 separate carpels .. 50 ote -. 4, DICHONDRA. 
** Leafless twining parasites. 
Corolla small, campanulate .. a8 ste . CuscuTa. 
Or 
