176 ANALYSIS OF A POLYPETALOUS HERB. 



ANALYSIS OF A POLYPETALOUS HERB. 



920. To determine the Cohort. A good specimen of a little yellow-flowered 

 herbaceous plant, common in the grassy fields of cool regions, is supposed to be now 

 in the hands of each pupil of the class. (1.) The first pupil, reading (if necessary) 

 the characteristic of each sub-kingdom, pronounces the plant one of the Phaeno- 

 gamia, and refers the next pupil to the Provinces, 1 or 2. 



(2.) The next reads the characters of those Provinces, and comparing the speci- 

 men (which has net-veined leaves and 5-merous flowers), concludes that it is an Exo- 

 gen. Refer next to the Classes, 1 or 2. 



(3.) " Flowers with stigmas, and pistils, &c. 



" Flowers with open scales instead of pistils (or no pistils at all)," &c. Our 

 plant has pistils, &c, and is (moreover, not a pine, spruce or cedar). It is, there- 

 fore an Angiosperm. Refer next to Cohort 1, 2, or 3. 



(4.) "Corolla with distinct petala" — This characterizes our plant, and it is pro- 

 nounced " Polypetalous." Refer then to (A). 



921. To determine the Natural Order, the (5th) pupil reads the first alterna- 

 tive, or triplet, noted by a star (*), and comparing his plant, finds it to correspond 

 with the first line, for it is an " herb with alternate leaves." Pass now to (11). 



(6.) "Flowers regular or nearly so. . Fruit never a legume." 



" Flowers irregular," &c. The flower is regular. Pass to (13). 



Again a pupil reads : — 



(7.) " Stamens 3 — 10 times as many as the petals." 



" Stamens few and definite." — The stamens are many. Pass to (15). Th« 

 next (8) pupil reads, compares, and determines that the stamens are " perigynous on 

 the base of the calyx," and announces the letter (t!) as the reference to the next 

 alternative. (9.) Next, the pupil reads and compares his specimen with the triplet 

 (d), and concludes that the sepals are 5. Refer then to the dash ( — ). (10.) Lastly- 

 the pupil determines that the sepals are imbricated in the bud, and consequently 

 belongs to the Nat. Ord. Rosacea. 



922. To determine THE Genus. After a careful comparison of his specimens with 

 the brief diagnosis of the Roseworts (page 325), in order to verify the analysis thus 

 far (11), the learner consults the Table of the Genera, and inquires the character of 

 the carpels, styles, &c, in order to learn the suborder of the plant. As the carpels 

 are many, and free, he concludes that it is of the Suborder Rosea;. Next learn ita 

 tribe. (12.) As the "carpels are 1-seeded in an open calyx," we infer that ite 

 tribe isRosidas. Refer to f. (13.) Are the "styles persistent," etc., or "deciduous," 

 etc. ? They are deciduous ; refer now to the dash ( — ). (14.) Inquire, " Calyx 

 bractless?" or " calyx bracteolate ?" As the calyx is bracteolate (having five little 

 leaves close to the calyx beneath, as if a double calyx), we refer again to the dash 

 ( — ). (15.) "Receptacle pulpy" or "spongy," or "dry?" The latter is true, 

 carrying us to the next dash ( — ). (16). Finally, are the "stamens oo," or "5?" 

 They are numerous, and Potentilla is the genus sought. 



923. To determine the Species. Having compared the generic description of Po- 

 tentilla with our specimens, and assured ourselves of its agreement thereto, (17.) we 

 next inquire, are the " leaves palmately 3-foliolate," " palmately 5-foliolate," or 

 "pinnate?" They are palmately 3-foliolate, and our plant is now referable to the 

 1st, 2d, or 3d species. (18.) Lastly, the italicized words alone in the description of 

 these species, at once mark our plant as belonging to the first, for it is hirsute, and 

 the sepals exceed the petals. The name is, therefore, P. Norvegica. 



