486 



DIMORPHOTHECA 



DIOON 



teeth, pilose, the uppermost smaller and narrower: pe- 

 duncles terminal, noddinej in f r. : tis. white above, pur- 

 ple or discolored beneath. Var. liguldsa, Voss (C(<}<^u- 

 diila Pongei, Hort. ), is a double form— the heads full of 

 ra^'s — with heads white on upper side and yellow or 

 violet beneath. 



Seven species have been pictured under various 

 names in the Botanical Magazine — all perennials, and 

 worth importation. 



D. auratitiaca, DC. Lvs. slender, entire: fls. yellow. B.M. 

 408.— C Bdrberice, Haw. Perennial: fls. purple above, paler be- 

 neath; disk all purple, with corollas of 2forms. B.M. 53^7.— 

 D. chrysantkemifdlia, DC. Lvs. cut like a Chrysanthemum: 

 fls. yellow, reverse reddish. B.M. 221H.— D. cu7iedta, DC. Lvs. 

 strongly cut: fls. scarlet-orange. B.M. 1343. — D. Ecklonis, DC. 

 Differs from all in its shrubby stem and branches, and is per- 

 haps the most promising of all. Fls. white, violet-blue, and 

 strongly veined on the back; the disk azure-blue. B.M. 7535.— 

 D. nudicaulis. var. grammifdlia, Harv. & Send. Fls. white, 

 with a purple ring at the base, and orange-brown on the back, 

 the disk purple. B.M. 5252.— Z>. TrAgus, DC. Lvs. narrower 

 than in D. Ecklonis, linear: fls. white, veined purple, the rays 

 narrower at the base, reverse orange purplish, the disk pur- 

 plish. B.M. 1981. ^, M. 



DI0CL£)A (after Diodes Carytius, said to be second 

 only to Hippocrates among the ancients for his knowl- 

 edge of plants). Leginniiids(e. About IG species of tender 

 shrubby twiners, mostly tropical American, with delicate 

 trifolioiate leaves and blue, violet, scarlet or white tls., 

 sometimes nearly an inch long, and borne in clusters 

 which have been roughly compared to Wistaria. Calyx 

 bell-shaped, 4-cut, 2 lobes shorter and narrower, stan- 

 dard wider than long: ovary nearly sessile; pod wide, 

 the upper suture thickened or 2-winged. The following 

 species is cult, in S. Calif., where it has a moderate 

 growth, shining foliage, and clusters of 10 or more large 

 fls. of a splendid scarlet. 



glycinoides, DC, from Rio de la Plata basin, is prob- 

 ably the only species grown in European gardens and 

 in California. Fls. 1 in. long, bright scarlet, in racemes, 

 somewhat like Wistaria: will stand some cold. Propa- 

 gated by seeds, cuttings, or suckers, freely produced 

 on grown up plants. (Syn. Camptosema ruhicundum, 

 Hook. & Am.) p Franceschi and W. M. 



DION. See Dioon. 



DION.S)A (an unusual name for Venus). Droserdce(F. 

 Venus' Fly-tkap. This insectivorous plant is one of 

 the wonders of the vegetable kingdom. See Fig. 713. 

 It closes its trap with remarkable quickness. The plant 

 grows wild only in the sandy savannas of North Carolina. 

 It is a perennial herb, the lvs. all radical and in a rosette, 

 the spatulate portion being regarded as petiole, and the 

 trap as the blade: fls. good sized, white, in a bracted 

 corymb, borne on a leafless scape. It is allied to the 

 sundews, other famous insectivorous plants which are 

 also cultivated, but has about 15 stamens, a columnar 

 style, and seeds at the base of the pod. Many famous 

 naturalists have studied and written about this plant, 

 and it has a large special literature. At times it is sold 

 widely throughout the north, often at high prices, but 

 the plants are soon "worked to death." It is difficult to 

 keep it more than a year in the north, but it ought to be 

 furnished in large quantities at low rates, so that all the 

 school children may see it. It is mostly grown in con- 

 servatories associated with botanical institutions. 



" It is seldom that this wonderful little plant is seen in a good 

 state of cultivation any length of time after removal from its 

 native haunts. Its cultivation in a gi-eenhouse is usually at- 

 tended with more or less difficulty, owing to unsuitable condi- 

 tions, such as too much dry air, shade or unfriendly soil. It 

 delights in fidl sunshine, with a very humid atmosphere. 

 When the plants can be secured and transplanted with con- 

 siderable of the soil in which they grow attafh^d to the bnlh- 

 like root-stalks, they are quite easily dealt wiih, .mmI m.'iv l..- 

 kept in a healthy growing state for years. I liinl a iMnml li.m;^ 

 ing earthenware receptacle most useful to^iou thmi in; tlie 

 bottom is carefully drained, first with largu picc^-, ut" biukeu 

 pots, then smaller pieces, and the upper layer is quite fine. 

 Some chopped fibrous peat is placed above this, when the plants 

 are biult in, with live sphagnum moss used to fill the spaces 

 between the clumps. Arranged in this way. it is hardly possible 

 to give them too much water, and they revel in abundant sup- 



plies. If kept in the sun the leaves take on a reddish tinge, but 

 when grown in the shade they are always green. Flowers will 

 develop about the middle of June, but they should be nipped off 

 as they make their appearance, for they are apt to weaken the 

 plant. 



"The Dionasa has been grown successfully in a dwelling 

 house by a very different method. The plants were in a wide, 

 shallow dish, without any drainage, and simply placed, not too 



713. The Venus' Fly-trap— Dionaea muscipula (X^). 



firmly, in loose live sphagnum moss, with a glass covering. 

 Water was given every other day by filling the space above the 

 plants until the disli was tilled, and then it was poured off. In 

 this way the potting material never became sour. From the 

 luxuriant condition in which these plants remained for years, 

 I am inclined to think this was a close imitation of the condi- 

 tions under which they thrive in a wild state. Some yerrs ago, 

 owing to Professor Asa Gray's endeavor to have the Govern* 

 ment purchase a strip of land on which this plant grows, there 

 existed a widespread idea that it was gradually becoming ex- 

 tinct. There seems to be little likelihood of this calamity, how- 

 ever, as Dionsea is found abundantly in some places all the way 

 from Wilmington to Fayette\'iUe, in North Carolina. Its per- 

 manency is all the more assured seeing that the plants thrive 

 on soil which is of little use for agricultural purposes."— O.TT. 

 Oliver, in Garden and Forest, 20:237 {1S97). 



muscipula, Ellis. Fig. 713. Described above. B.M. 

 785. P.S. 3:280. Mn. 1:69.-The genus has only one 

 species. 'VV. M. 



DIdON (Greek, two and egg; each scale covers two 

 ovules and the seeds are in pairs). Cycadctcece. Hand- 

 some foliage plants suitable for warm or temperate palm 

 houses. This once powerful order is now nearly extinct, 

 and the few remaining species are of the greatest scien- 

 tific interest and also decorative value. D. edule has a 

 flat, rigid frond which is more easily kept free from 

 scale insects than Cycas revoluta, the commonest species 

 of the order in cultivation. A specimen at Kew had a 

 trunk 3-4 ft. high and 8-10 in. thick, the crown spread- 

 ing 8-10 ft. and containing 50 fronds, each 4-5 ft. long 

 and G-9 in. wide. Both sexes make cones frequently, 

 the male cone being 9-12 in. long and the female 7-12 in. 

 The seed.s, which are about the size of Spanish chest- 

 nuts, are eaten by the Mexicans. Many Cycads yield 

 arrowroot. This genus is said to be the closest to the 

 fossil forms of any living representative of the order. 

 The genus has the cones and twin seeds of Zamia and 

 Encephalartus, with the flat, woolly scales of Cycas, but 

 without the marginal seeds and loose inflorescence of 

 the lattur. Prop, by seeds. Culture same as Cycas. 



6dule. Liudl. Lvs. pilose when young, finally gla- 

 brou.s.;j-5 ft. long, pinnatifid, rigid, narrowly lanceolate 

 segments,about lOOoneach side, linear-lanceolate, sharp- 

 pointed, widest at the base, rachis flat above, convex 

 I)eneath: male cones cylindrical, female cones ovoid. 

 Mex. B. M. 0184. Gu. 55, p. 365. Gt. 48, p. 157. Var. 



