90 PORTULACACE/E. pohtulaca. 



Order XIII. PORTULACACE^E Reichb. Consp. 161. 



More or less succulent herbs with simple entire leaves and 

 regular perfect flowers. Sepals only 2 (sometimes more in 

 Lewisia). Petals 5 and definite or indefinite, imbricated in aes- 

 tivation. Stamens opposite the petals when of the same num- 

 ber or fewer; filaments all fertile, distinct; anthers fixed by 

 the middle, versatile or introse. Ovary 1-celled by the obliter- 

 ation of the dissepiments, with few or many campylotropous or 

 amphitropous ovules on a free central placenta, in fruit be- 

 coming a capsule with transverse or loculicidal dehiscence. 

 Embryo curved or coiled on the outside of mealy albumen. 

 Flowers axillary or terminal . mostly ephemeral. 



* Capsule dehiscing transversely near the middle : sepals united to 

 near the middle, and in ours adnate to the ovary, the upper portion at 

 length deciduous. 



1. Portulaca. Petals 4-6 periginous : stamens 9-20. 



* * Capsule dehiscing transversely at the very base : sepals per- 

 sistent. 



2. Lewisia. Sepals 6-8 ; marcescent-persistent : petals 10-16 : scapes 1- 

 flowered, jointed and bracteolate near the middle. 



3. Oreobroina. Sepals 2 : petals 3-10, usually 7 ; stems scape-like with a 

 pair of (at least when young) opposite bracts below the inflorescence, 

 1-many-flowered . 



* * * Capsule loce.licidally 3-valved: sepals 2, ovary several- 

 ovuled : petals 3-several. 



4. Calandrinia. Sepals 2, persistent: petals 3-7: stamens 3-10, seldom 

 of the same number as the petals. 



5. Talinum. Sepals 2, deciduous : petals 5. 



* * * * Capsule loculicidally 3-valved : sepals 2, persistent : petals 5. 



(>. Claytonia. Capsule several-seeded : stamens 10, inserted on the claw 



of the free and equal petals. 

 7. Montia. Petals 5, more or less distinctly united at the base, un- 

 equal : stamens mostly 3, inserted on the claws of the 3 smaller petals. 



* * * * * Capsule 2- valved : sepals 2, broad, more or less Bcarious, 

 persistent. 



S. Spraguea. Sepals emarginate at base and apex : petals 4: stamens :'>, 



exserted, opposite the .'5 larger petals. 

 i>. Calyptridium. Sepals mostly unequal, petals 2-4; stamens 1, 2 or 3, 



shorter than the petals and alternate with them. 



§ 1 Capsule circumscissile. 



1 PORTULACA Tourn, Inst. 236: 



Low succulent diffuse or ascending herbs with alternate or op- 

 posite leaves scarious or setaceous stipules and axillary or ter- 

 minal epherma] yellow or rose-color flowers in summer. Sepals 

 2, coherent at base into a tube and adnate to the base of the 

 ovary, the free upper portion at length deciduous. Petals 4-6. 

 Stamens 4-20, perigynous with the petals. Style 1, deeply 3-8- 

 clel't. Capsule ctrcumscissile near the middle, many-seeded. 



