ARCTIUM 
247 
and stimulant, but is said to be devoid of medicinal value. For 
A. papyrifera Hook, see Fatsia. 
Araliaceae. Dicotyledons (Archichl. Umbelliflorae). 51 gen. 400 sp. 
mostly trop., the chief centres being the Indo-mal. region and trop. 
Am. Mostly trees and shrubs ; some are almost like palms in habit 
(p. 155). Many twine, others ( eg . Hedera) climb by aid of roots. 
Leaves usually alt., often large and compound, with small stipules. 
Firs, small, in umbels which are frequently massed into large com- 
pound infls. Fir. $, regular, epigynous, usually 5 (3-00 )-merous. 
K5, very small; C 5; A 5; 0(5), 5-locular, with 1 anatrop. pendulous 
ovule in each, the micropyle facing outwards. Styles free or united. 
Fruit usually a drupe with as many stones as cpls. Embryo small in 
rich endosperm. Chief genera: Fatsia, Hedera, Aralia, Panax. 
[Placed in Umbelliflorae (Eichl. Warm.), Umbellales (B. and PI.)] 
Araucaria Juss. Coniferae (Arauc. ib; see C. for genus characters). 
10 sp. S. Am., Austr., divided into 2 sections. To § 1, Colymbea 
(leaves broad, fruiting cpls. not winged), belongs A . imbricata Pav. 
(Chili), the monkey-puzzle of our shrubberies. Its seeds are edible 
and the wood is useful. A . Bidwilli Hook. (Austr.), the Bunya- 
Bunya pine, also belongs to this section. To § 2, EutcLcta (needle 
leaves, scales winged), belong A. excelsa R. Br., the Norfolk I. pine, 
and others. 
Araucariaceae. An order of Coniferae (< q . v.). 
Araujia Brot. Asclepiadaceae (11. 2). 10 sp. S. Am. 
Arbutus (Tourn.) Linn. Ericaceae (11. 6). 20 sp. Medit., Orient., 
N. Am. A. UnecLo L., the strawberry tree, is abundant at Killarney. 
The frt. (a dry berry) resembles a strawberry at a distance. It ripens 
in the second year, so that flr. and frt. occur together on a tree. 
Arceuthobium Bieb. Loranthaceae (2). 9 sp. N. temp. See Nat . 
Pfl. and Johnson in Ann. of Bot. II., p. 137. 
Archangelica Hoffm. Umbelliferae (6). 7 sp. N. temp. The petioles 
of A. officinalis Hoffm. are used in confectionery (angelica). 
Archegoniatae. A term used to designate that division of the Veg. 
Kingdom in which the ? cell (ovum) is contained in an archegonium, 
i.e. a flask-shaped organ with a neck formed of one layer of cells. It 
includes the Bryophyta and Pteridophyta. 
Archichlamydeae. One of the two primary divisions of Dicotyledons 
(p. 127). 
Archontophoenix H. Wendl. et Drude. Palmae (iv. 6). 3 sp. 
E. Austr. 
Arctium Linn. Compositae (xi). 1 sp., A. Lappa L., the burdock, 
often split into 4 sp., Eur. (incl. Brit.), As. The involucral bracts 
become hooked and woody after the firs, wither, and aid in seed 
distribution. They adhere to the fur or clothes, but are soon tom 
from their hold and the plant springs back again without parting from 
them, jerking out the fruits. 
