172 



NATURAL RISTOEY OP PLANTS. 



we have added Curtisia ' and Mastixia,^ but excluded Hehvingid,^ 

 which we have referred to the Cornacece. The total number of species 

 is about 1900. 



In all these plants some common characters are constant, all of 

 the highest value, as : the concave form of the floral receptacle ; the 

 independence of the petals; the presence (at adult age) in each 

 ovarian cell of a single descending ovule,* with micropyle exterior 

 and superior; the existence in the seed of a horny or fleshy albumen 

 and an embryo shorter, generally much shorter, than the albumen.* 



Other characters are very frequent and very important, without 

 however- being constant. Among others we may mention : com- 

 pound leaves ; * the herbaceous consistence of the stems ; ' the two 

 cells of the ovary,' and the fruit consisting of a diachene ^ in the 

 Umbelliferce proper; the presence in the pericarp of reservoirs of 

 oleoresinous substances ^° which give the fruits their aromatic 



' Adansonia, iii. 334 ; xii. 163. 



» Bull. Soc. Linn. Par. 159. 



3 See p. 69, 80 ; Bull. Soc. Linn. Par. 137. 



* At first, as Payer has stown, in the types 

 examined, there are two ovules in each cell, 

 both descending, or one more or less ascending. 

 The latter may persist for a longer or shorter 

 time or even to maturity in plants with very 

 large ovarian cells, and also in some others. 

 "We have observed this many times in Eryn- 

 glmn, Peucedanum, and Trachymene. 



* It may he as much as half the length of the 

 albumen or nearly so as, for example, in some 

 Feridas, Curtisia, Palimiia^&g. 90, p. 100), &c. 



* Not unfrequently simple in the Araliece, 

 more rarely in the true UmbellifertB, particularly 

 in Buplevrum, Eryngium, and a great many 

 Hydrocotylece ; reduced to cylindrical petioles, 

 often transversely partitioned, in Crantzia, Ho- 

 henacheria, Mhyticarpus, &c. 



' Woody in some species of Tornnbema, Peii- 

 ccdanum, Eryngium, Bupleurum, Angelica, Sie- 

 iera, and in most of the Araliece, or they may 

 even become climbing and very long, or stumpy, 

 little divided or simple so that at a distance 

 these plants resemble palms in habit. The 

 structure of these stems has been partially 

 studied by several authors: G. deBuzae, jIkk. 

 Se. Nat. ser. 2, i. t. 6. — Joohmann, Be TImhelhf. 

 Struct, et Evol. Nommlla (Breslau, 1865). — 

 Link, Icon. Anat. Bot. (1837) faso. x. 2, 6 ; xii. 

 1_3. — C. H. ScHULTZ, Nov. Acta Nat. Cur. 

 (1841), xviii. Suppl. 2, t. 2), 22.— Haktig, Bot. 



Zeil.{lib%) 96. — TJngbr, Beitr.zur Kenntn. Par, 

 PJl. (1841) t. 6 (Sedera).—K. Gkay, Introd. 

 (1858) U8(.4raKff). Trechl has most minutely 

 examined the structure of these plants, chiefly 

 with regard to the distribution and organiza- 

 tion of the sap reservoirs, both in the Umielii- 

 ferm {Comp. Send. Acad. Sc. Ixiii. 154, 201, 247 ; 

 Adansonia, vii. 118) and in the Araliece [Compt. 

 Mend. Ixi. 1163 ; Adansonia, viii. 102). 



* The abnormal flowers with three ovarian 

 cells are very rare ; we have seen them only in 

 some specimens of Conium, Ligustieimi and Peu- 

 cedanum. In the Araliece they often equal or 

 exceed the number of petals, since some Pleran- 

 dras are said to have nearly a hundred. But it 

 is also known that there are Ta»,n.y Araliece ■wiMi 

 a bilocular ovary. 



' The Araliece with dimerous fruit have also 

 been distinguished from the true UmbelUfercB 

 because their carpels do not separate at any age 

 nor quit an interposed columneUa. But Myo- 

 'docarpus, whose achenes are not detached at 

 maturity, is inseparable from Belarbrea which 

 does not present this peculiarity. So also Ho7-s- 

 jieldia and Astrochiche, formerly placed among 

 the VmbellifercB and scarcely distinct from some 

 forms of Panax. There are, moreover, many 

 true Umbellifers without carpophore. 



'" Especially studied by TiitcDL (see p. 87, 

 note 8), these reservoirs or vitta3 represent 

 secreting canals. See also Sachs, Text Bk. of 

 Bot. 73, 110. 



