ARAC] 



Q\)t Ereatfurg ai 3Sfltanp. 



84 



enlarged process, which is the growing 

 point of the flower-branch, and analogous 

 to the succulent receptacle of the straw- 

 berry, the dry core of the raspberry, 

 the spongy excrescence called the oak 

 apple, and even the stiff hard spine of 

 the Gleditschia. Scarcely more than 200 

 species are known. The appearance pre- 

 sented by this very distinct race of plants, 

 is shown in plate 2, in which a group of 

 Caladiums is seen at fig. b. 



ARACHIS. A genus of leguminous 

 plants, remarkable for the peculiar struc- 

 ture of its calyx, and the habit of thrusting 

 its fruit into the ground. M. Poiteau, in 

 the Annates des Sc. Nat, 1853 (xix. 268), 

 gives a good description and figure of 

 A. hypogcea. The principal characters of the 

 genus are the immensely long tube of the 

 calyx, whose limb is two-lipped ; the corolla 

 papilionaceous and yellow; and eight sta- 

 mens united into one parcel. The ovary 

 is very small, and placed at the bottom 

 of the very long calyx tube ; it contains 

 two ovules, and is terminated by a very 

 long style, thickened at its extremity, and 

 covered with hairs at the place where it 

 comes in contact with the stamens. After 

 the fall of the flower, the ovary, which is 

 very small, is gradually raised upon a stalk 

 which in time attains a length of two to 

 three inches, and in its growth curves 

 downwards, so that at length the small 

 ovary at its extremity is thrust into the 

 ground. When this happens, the ovary 

 begins to enlarge, and ripens into a pale 

 yellowish wrinkled slightly curved pod, 

 often contracted in the middle, and con- 

 taining two seeds. Should the ovary by 

 some accident not be enabled to thrust its 

 pods into the ground, it withers and does 

 not attain perfection. The plant was 

 originally a native of the West Indies and 

 West Africa, but is now cultivated in 

 warm climates, preferring a light sandy 

 soil. The seeds which are of the size of 

 a pea are eaten as food, but are chiefly 

 valuable for the quantity of oil they pro- 

 duce when pressed. The oil is used as a 

 substitute for that of olives, to which it 

 is equal in quality. The plant might with 

 much advantage be extensively cultivated 

 in Australia and others of our colonies for 

 the sake of its excellent oil, while the 

 herbage would form valuable forage for 

 cattle, who eat it greedily. The pods are 

 known in this country as Ground Nuts. 

 The peculiarity of thrusting the fruit into 

 the soil to effect its maturation there, is 

 not confined to this genus, but exists also 

 in the allied genus Voandzeia, a native of 

 Surinam, where its seeds are eaten, like 

 those of the Arachis, as peas by the 

 negroes. [M. T. M.] 



ARACHNIODES. A doubtful genus of 

 ferns, supposed to belong to the Peranemecr. 

 or Alsophilerp. The veins of the fronds are 

 free, and the sori are said to have an 

 arachnoid or cobweb-like involucre cover- 

 ing them. The only recorded species is a 

 native of Java. [T. M.] 



ARACHNIS ffrom the Greek : a spider) 

 A Javanese orchid, of epiphytal habit, 

 whose name has been derived from the 

 extraordinary resemblance of its flowers 

 to a huge spider. The plant has flowers 

 live inches in diameter, of a lemon colour, 

 with great purple spots; they grow as 

 many as twelve together, on a long loose 

 spike arising from one side of a strong 

 scrambling stem. They are said to have 

 the most delicate smell of musk, but so 

 penetrating withal that a sinsle spike will 

 scent an entire meeting-hall. Koempfer, 

 however, asserts that this odour resides 

 exclusively in the ends of the sepals and 

 petals, which are broader at the end than 

 elsewhere ; and he says that if they are 

 I cut off all fragrance ceases. The plant 

 has had several names, as Epidendrumflos 

 aeris, Aerides arachnites, Renanthefd ara- 

 chnites, and Arachnls moschifera. It is 

 \ called in Java, Katong ging. Undoubtedly 

 ; it is one of the most remarkable plants of 

 its remarkable order, and it is not a little 

 surprising that it should never have been 

 introduced into Europe. 



J ARACHNITIS is a name given to the 

 ; spider Ophrys. 



| ARACHNOID. Resembling cobweb in 

 appearance ; seeming to be covered with 

 cobweb, in consequence of the entangle- 

 ment of long white hairs. 



ARACHNOTHRIX. A genus of plants 

 closely related to Bondeletia, from which it 

 differs in having the corolla four-pai-ted, 

 with its tube and throat smooth. The 

 anthers are placed towards the top of the 

 tube of the corolla on very short filaments. 

 The plants are covered with a more or less 

 cobweb-like clothing of hairs, hence the 

 name. It belongs to the natural order 

 Cinchonacece. [M. T. M.] 



ARADS. An English name for the 

 Aracece or Arum family. 



ARALIA. This genus is the type of the 

 order Araliacece, and consists of trees, 

 shrubs, and herbs of rather striking cha- 

 racter, found in North America, and in 

 New Zealand, Japan, and the East. The 

 flowers are inconspicuous, collected in um- 

 bels, the umbels not unfrequently ranged 

 in large compound panicles. The calyx 

 has a very short superior limb, which 

 is entire or five-toothed ; the corolla con- 

 sists of five petals inserted on the margin 

 of the epigynous disk ; the stamens are 

 five in number, alternating with the petals ; 

 and the ovary is inferior, five to ten-lobed, 

 with a solitary pendulous ovule in each 

 cell, and becomes a berry-like drupe. The 

 foliage is very various in character, but 

 generally of an ornamental aspect ; some- 



1 times simple, entire, or lobed, sometimes 

 digitate, pinnate, twice ternate, bipinnate, 



j or supradecompound. Some of the species 

 have smooth, and others prickly stems. 

 One of the former, A. racemosa, grows three 

 to four feet-in height, with a divaricately- 



I branched herbaceous stem, bearing com- 



