GENTJ8 TRITONIA (MONTBRETIA). 



735 



Differentiation of Certain Starches of the Genus Tritonia. 



HlBTOLOGICAL CHARACTERISTICS. 



Conspicuous Forms. 



T. erocata: Mostly or solely simple, numerous aggre- 

 gates or compounds in form of doublets and trip- 

 lets, many doublets consist of a large grain having 

 a small grain partially embedded, rounded and 

 regular. Few grains with pressure facets. Spheri- 

 cal and transitional forms between them and 

 ovoid and elliptical. Doublets oval to flattened 

 ovoid and broad ovoid. Spherical when seen on end. 



T. crocala var. lilacina: Essentially the same as in T. erocata. 



T. erocata var. rosea: Essentially the same as in T. 

 crocala, excepting a relatively large number of 

 doublets and a less number of small grains. 



T. securigera:' Essentially the same as in T. erocata, except 

 that the spherical forms are more conspicuous, and 

 fewer aggregates. 



T. pottsii: Simple, many grains with pressure facets; 

 rounded and fairly regular, hemispherical, ovoid, 

 rounded ovoid and spherical. Differ materially 

 in general resemblances from T. erocata, but 

 closely resemble T. erocosmceflora. 



T. croeosmoeflora: Essentially the same as T. pottsii. 



Hilum — Form, Number, and Position. 



T. erocata: Form indistinct, small, round, rarely slightly 

 fissured, sometimes multiple. Position centric or 

 slightly eccentric. 



T. crocala var. lilacina: Form essentially the same as T. 

 erocata. Position centric or slightly eccentric. 



T. crocala var. rosea: Form essentially the same as in 

 T. crocala. Position centric or slightly eccentric. 



T. securigera: Form fairly distinct, large, no fissures, 

 sometimes multiple. Position centric or sUghtly 

 eccentric. 



T. pottsii: Form fairly distinct, small, round, single or 

 occasionally double, often fissured, a single short 

 fissure or 3 fissures or stellate. Position usually 

 eccentric about two-fifths to one-third of the 

 longitudinal axis. 



T. crocosmwflora: Form distinct, small, round, single, 

 rarely double, often a single shallow and short 

 fissure, or stellate. Position usually eccentric 

 about two-fifths of the longitudinal axis. 



Lamellce — General Characteristics and Number. 



T. crocala: Very indistinct, fairly fine, regular, continu- 

 ous rings; about 10 on the larger grains. 



T. erocata var. lilacina: Very indistinct, rather coarse, 

 regular, continuous rings; about 7 on the larger 

 grains. 



T. erocata var. rosea: Very indistinct, regular, compara- 

 tively coarse, continuous rings; about 8 on the 

 larger grains. 



T. securigera: Rather indistinct, rather coarse, regular, 

 continuous rings; about 4 to 5 on the larger grains. 



T. pottsii: Not as a rule distinct; rather coarse, regular, 

 continuous rings; 10 to 12 on the larger grains. 



T. croeosmoeflora: Essentially the same as in T. pottsii; 

 8 to 10 on the larger grains. 



Size. 

 T. crocala: From 3 to 26m, commonly 18^. 

 T. crocala var. lilacina: From 3 to 26m, commonly IS/i. 

 T. crocala var. rosea: From 4 to 27/i, commonly 17m. 

 T. securigera: From 2 to 30m, commonly 18m. 

 T. pottsii: From 3 to 32m, commonly 20m. 

 T. croeosmaflora: From 2 to 34m, commonly 20m. 



PoLABiscopic Properties. 



Figure. 



T. crocala: Centric or slightly eccentric, not as a rule, 



clear-cut, lines straight. 

 T. arocaia var. lilacina: Essentially the same as in T. erocata. 



PoLABiscopic Pbopbrties. — Continued. 

 Figure. — Continued. 



T. crocala var. rosea: Essentially the same as in T. 



crocala. 

 T. securigera: Essentially the same as in T. crocala. 

 T. pottsii: Usually eccentric, not clear-cut, lines may be 



bent or otherwise distorted. 

 T. croeosmoeflora: Essentially the same as in T. poUsii. 



Degree of Polarization. 

 T. crocala: Fair, not much variation. 

 T. erocata var. lilacina: Fair, probably shghtly higher 



than in T. crocala. 

 T. erocata var. rosea: Fair, probably slightly higher than 



in T. crocala. 

 T. securigera: Fairly high, variable, distinctly higher 



than in T. crocala. 

 T. pottsii: Fairly high, variable, distinctly higher than 



in T. crocala. 

 T. erocosmceflora: The same as in T. pottsii, except more 



variable and shghtly higher. 



Polarization with Selenite — Quadrants and Colors. 

 T. erocata: Quadrants, as a rule, not sharply defined, 



tend to be regular in shape, and equal in size. 



Colors fairly pure. 

 T. crocala var. lilacina: Quadrants essentially the same 



as in T. crocala. Colors fairly pure. 

 T. erocata var. rosea: Quadrants essentially the same as 



in T. crocala. Colors fairly pure. 

 T. securigera: Quadrants essentially the same as in T. 



erocata, but greater tendency to inequality in size. 



Colors fairly pure. 

 T. pottsii: Quadrants fairly well defined, tend to be 



irregular in shape and unequal in size. Colors 



fairly pure. 

 T. croeosmoeflora: Quadrants the same as in T. pottsii. 



Colors fairly pure. 



Iodine Reactions. 

 Intensity and Color. 

 T. erocata: Fair; blue-violet. 

 T. crocala var. lilacina: Fair, sUghtly more than in T. 



crocala; blue-violet. 

 T. crocala var. rosea: Fair, slightly more than in T. 



erocata; blue-violet. 

 T. securigera: Fair, but not so much as in 2". erocata; 



blue- violet. 

 T. pottsii: Light, less than in T. crocala; blue-violet. 

 T. croeosmoeflora: Fair, more than in T. pottsii, but less 



than in T. erocata; blue-violet. 



Staining Reactions. 

 With Gentian Violet. 

 T. erocata: Very lightly. 

 T. crocala var. lilacina: Very lightly, about the same as 



in T. erocata. 

 T. crocala var. rosea: Very lightly, about the same as in 



T. crocala. 

 T. securigera: Very Ught, lighter than in T. crocala. 

 T. pottsii: Fair, deeper than in T. erocata. 

 T. crocosmaflora: Light, less than in T. pottsii, but more 



than in T. erocata. 



With Safranin. 

 T. erocata: Fair. 

 T. erocata var. lilacina: Fair, about the same as in T. 



crocala. 

 T. crocala var. rosea: Fair, about the same as in 7. 



crocala. 

 T. securigera: Very light, much less than in T. erocata. 

 T. pottsii: Fair, about the same as in T. erocata. 

 T. erocosmceflora: Fair, less than in T. pottsii and T. 



erocata. 



