M5SS0N 32.] HOW TO STLDY PLANTS. 193 



the blosfom, holds good universally, while the plan of the stem 

 does. 



559. The single flower of our plant with distinct calyx and corolla 

 takes us over the vSpadiceous to the Petaloideous Division: 

 the Petaloideous Division of Endogens there begins on p. 28, 

 These parts being free from and beneath the ovary, refer us to the 

 third subdivision, viz : "3. Perianth wholly free from the ovary." 



5o9\ The pistil is next to be considered: it accords with' the third 

 of the triplet : " Pistil one, compound (cells or placentae 3) ; anthers 

 2-celled." Under this follows a triplet, of which the initial word is 

 "Perianth": our choice falls upon the first, as there is nothing 

 " glumaceous '' about this flower. 



560. The succeeding triplet relates to the stamens; here 6, so 

 we take the first alternative. The next refers to mode and place of 

 growth: our plant is "Terrestrial, and not rush-like." The next 

 again to the perianth : the second number of the triplet : " Perianth 

 of 3 foHaceous and green sepals, and 3 colored withering-persistent 

 petals " (as would be seen after flowering-time), brings us to a par- 

 ticular group in the great Lily family, or Liliace^, p. 520. 



561. Reading over the family character, and collating the five 

 tribes comprised, we perceive that our plant belongs to the group, 

 quite peculiar among Liliaceous plants, here ranked as Tribe I. 

 TkillidEvE, the Trillium tribe. And the next step, leading to a 

 choice between two genera, determines the genus to be Trillium. 



562. Turning to this, on p. 522, and reading the full description 

 of it, we proceed to the easy task of ascertaining the species. ' The 

 " flower is raised on a peduncle," as in § 2. This peduncle is slender 

 and nearly erect, and all the other particulars accord with the sub- 

 division marked by a single star. And, finally, the ovate, acutish, 

 widely-spreading, dark dull-purple petals mark the species as the 

 Pduple Birthroot, Trillium erectum, L. 



563. By the Field, Forest, and Garden Botany, the analysis is 

 similar, only more simple. The details need not be particularly 

 recapitulated. 



564. The student residing west of New England will also be 

 likely to find another species, with similar foliage, but with larger, 

 pure white, and ,obovate petals, turning rose-color when about to 

 fade. This will at once be identified as T. grandiflorum. And 

 towards the north, in cold and damp woods or swamps, a smaller 



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