GENERA MARANTA AND CALATHEA. 



831 



NOTES ON THE STARCHES OF MARANTA. 



Differences in the starches of the several species and varieties of this genus are very striidng. 

 Taking the starch of M. arundinacea as the type, it will be seen that the starches of the two varieties 

 (see plates 88 and 89, figs. 523 to 534) and M. musaica belong to the same common type, the starches 

 in each case being readily differentiated from each other, except probably as regards the two varie- 

 ties. The starches of M. massangeana (stated by the grower to be the true species) and M. leuconeura 

 have an entirely different type of grain. Notwithstanding this difference in the types of grains the 

 reactions are in close correspondence. The starch of M. musaica differs quite as much from M. 

 arundinacea and its varieties, although the grains belong to the same type, as do the starches of 

 M. massangeana and M. leuconeura from the same group. The correspondence between the reac- 

 tions of M. arundinacea and its varieties is very marked; and M. massangeana differs from the 

 former chiefly in the aniline, temperature, and chloral hydrate-iodine reactions; M. leuconeura 

 differs particularly in the aniline and temperature reactions; and M. musaica most noticeably in 

 the aniline, temperature, chloral hydrate-iodine, chromic acid, pyrogallic acid, ferric chloride, and 

 Purdy's solution reactions. The latter differs very markedly from the other Marantas and bears 

 on the whole such close resemblances to Calathea that it seems that it should be classed with the 

 latter. 



GENUS CALATHEA. 



As stated under Maranla, most forms of the latter offered by the trade are Calatheas. These 

 two genera and Stromanthe, Phrynium, and Thalia are closely related, all of which are in common 

 cultivation mainly because of their fine foliage. The genus Calathea contains from 70 to 80 species, 

 all natives of tropical America and Africa, chiefly the former. Starches were obtained from four 

 species: C. lietzei Morr., C. wiotiana Makoy (C. wioti Hort.), C. vandenheckei Regel, and C. vittata 

 Kcern. The Calatheas studied in this section were received from horticulturists marked Marantas, 

 and it was not until after the laboratory studies had been recorded, and comparisons made with 

 Maranta arundinacea var. (Commercial No. 1), that it was found that they were Calatheas. 



STARCH OF CALATHEA LIETZEI. (Plate 90, figs. 535 and 536. Chart 351.) 



Histological Characteristics. — In form the grains are simple, with no compounds, aggregates, 

 clumps, or pressure facets. The surface is usually irregular owing to the unequal development. 

 The conspicuous form is the clam-shell type, the grains 

 being usually somewhat longer than broad; also triangu- 

 lar with rounded corners, oval, elliptical, almost spherical, 

 and elongated dome-shaped. The grains are flattened, 

 and commonly about one-third to one-half as thick as 

 wide. On edge they appear to be of a long, slender, ovoid 

 form, the distal end being narrower than the proximal 

 end. Frequently the proximal end is nodular, owing to 

 lateral depressions, and the distal end is often notched. 



The hilum is a rather small, fairly distinct, round spot, 

 usually eccentric about one-fifth of the longitudinal axis of 

 the grain and in or near the median line. There are no 

 multiple hila. The hilum is sometimes marked by a round 

 cavity or by a shallow and clean-cut fissure, which may 

 be straight or curved, transverse or longitudinal. Rarely 

 a number of thin fissures radiate from the hilum. 



The lamellae are fairly distinct, rather fine circles or 

 arcs of circles. They are quite regular, and a short dis- 

 tance from the hilum tend to follow the marginal outline. 

 They vary somewhat in size in different grains and are 

 usually larger and more distinct near the distal end. There are 16 to 20 on the larger grains. 



The grains vary in size from 4 to 32/i. The common size is 22/i. 



Polariscopic Properties. — The figure is eccentric, fairly distinct, but usually not clear-cut, as 

 the lines are usually wide and not sharply defined, and broader and even less defined near the margin. 

 They are sometimes somewhat bent or otherwise distorted or bisected. 



P I GV T P 

 S 



Curve 



QartNo. 351. 



GV S T CI CA PA FC P S CI PA CA 



Reaction-Intensities of Surch of Calathe 

 lietzei. 



