500 



PORTULACE^E. 



[Hypogynous Exogens. 



Order CXC. PORTULACEvE.— Purslanes. 



Portulace*, Jus*. Gen. 313. (1789) in part; A.St.EU. Mem. %%*** (1815) ^.*5*£ £ 

 (1828) ; DC. Mim. de la Soc. a" Hilt. Nat. de Pans, Aug. (182,) ; Endl. Gen. ecu. , Jieimer uen. 

 130.; Wight lllustr. 2. 41. 

 Diagnosis.-- KM Exogens, with the calyx and corolla unsymnutrical §, the latter usually 

 conspicuous, amphitropal ovules, and alternate succulent leaves without sUpules. 

 Succulent shrubs or herbs. Leaves alternate seldom opposite entire without 

 stipules, often with bundles of hairs in their axils. Flowers axillary or terminal, 

 usually ephemeral, expanding only in bright sunshine, 

 unsymmetrical in their calyx and corolla. Sepals 2, 

 cohering by the base. Petals generally 5, either distinct 

 or cohering in a short tube. Stamens inserted along 

 with the petals irregularly into the base of the calyx or 

 hypogynous, variable in number, all fertile, sometimes 

 opposite the petals ; filaments distinct ; anthers versa- 

 tile, with 2 cells, opening lengthwise. Carpels 3 or 

 more, combined into a one-celled ovary, which is 

 usually free (or partially adherent) ; style single or 

 none ; stigmas several, much divided ; ovules amphi- 

 tropal. Capsule 1 -celled, dehiscing either transversely 

 or by valves, occasionally 1 -seeded and indehiscent. 

 Seeds numerous, if the fruit is dehiscent ; attached to 

 a central placenta ; albumen farinaceous ; embryo 

 curved round the circumference of the albumen, with 

 a long radicle next the hilum. 



Ovary partially adherent in some Portu'acas. 

 In general the Purslanes are easily recognised by 

 their succulent condition and gay ephemeral flowers ; 

 but in some the flowers are inconspicuous, and in 



others the succulence inconsiderable. They, in such 



cases, would have little to distinguish them from 



Cloveworts (Caryophyllaeere), except their 2-leaved 



calyx, and that in truth, combined with the other 



characters, furnishes the essential mark of the Order. 



Endlicher, however, extends the limits of the Purslane 



group much beyond this, admitting a number of peri- 



gynous genera" whose flowers are quite symmetrical. 



These are spoken of elsewhere. In his view, the 



difference between Purslanes and Cloveworts consists 



mainly in this, that the former have the stamens 



alternate with the sepals when they are equal to them 



in number, and the latter opposite under the same 



circumstances. But in Orders where the number of 



stamens is sometimes indefinite and sometimes has no 



sort of relation to the sepals, as is, in fact, the case 



with the whole Portulaceous Order as it stands here, 



it is plain that such a distinction has no existence. 



I have, therefore, thought it advisable to reject a 



portion of Endlicher and Fenzl's Purslanes, in which 



the perigynous insertion is very marked, placing them in the Ficoidal Alliance, while 



all his hypogynous genera with symmetrical flowers are conveniently arranged among 



the Cloveworts. The principal deviation from the general features of the Order strictly 



limited, consists in some species having the ovary partially adherent, and the stamens, 



therefore, perigynous. Such instances seem to connect the Order with the genera 



just alluded to. From Knotworts (IUecebracese) the monospermous genera of Purs- 

 lanes are distinguished by the want of symmetry in their flowers, and by the stamens 



being opposite the petals instead of the sepals. De Candolle remarks, that PursUUM* 



Fig. CCCXWII.— Portnlaca australis.— Endlicher. 1. a flower; 2. an expanded corolla ; 3. a pistil; 

 4. a ripe fruit ; 6. a section of it. 





/ 



Fig. CCCXLHI. 



