Family 4. PARNASSIACEAE 



By Per Axei. Rydberg 



I 



Glabrous perennial herbs, with short rootstooks and in most species (in 

 all ours) with scapiform stems. I^eaves entire, mostly basal and petioled, the 

 single cauline leaf or bract usually sessile. Scape usually 1-flowered. Hy- 

 panthium short and usually poorly developed. Sepals 5, imbricated. Petals 5, 

 imbricated, white or pale-yellow, conspicuously veined, deciduous. Stamens 

 5, hypogynous or perigynous, alternate with the petals and with 5 clusters of 

 more or less united staminodia which in our species are gland-bearing at the 

 ends ; filaments subulate ; anthers introrse or subextrorse. Gynoecium of 3 or 

 4 united -carpels ; ovary superior to half-inferior, with 3 or 4 parietal placentae ; 

 style short or none ; stigmas 3 or 4, over the placentae. Ovules numerous, 

 anatropous. Capsule 1-celled, loculicidal at the apex, with 3 or 4 valves ; 

 Seeds numerous, winged ; endosperm wanting ; embryo straight. 



The family consists only of the following genus : 



1. PARNASSIA (Tourn.) L. Sp. PL 273. 1753. 



Characters of the family. It contains about two dozen species growing in wet places 

 in temperate and subarctic regions. 



Type species, Partiassia palustris L. 



Staminodia united below into an obovate scale, fringed above with the free 

 portions of the filaments. 

 Petals fimbriate on the sides, at least below. 



Free portions of the staminodia very short and stout ; leaf -blades reni- 

 form or cordate, usually broader than long. 

 Petals obovate, 5-nerved; staminodial scales with 5-9 lobes; sepals 



elliptic. 1. P.fimbriata. 



Petals oblong, 3-nerved ; staminodial scales with 3-5 lobes ; sepals nar- 

 rowly lanceolate. 2. P. rivularis. 

 Free portions of the staminodia long and filiform. 



I^eaf-blades ovate to reniform, long-petioled. 3. P. intermedia. 



Leaf-blades oval, short-petioled. 4. P. cirrata. 



Petals entire, not fimbriate. 



Petals 5-9-veined, usually exceeding the sepals ; capsule less than twice 

 as long as the sepals ; bract some distance from the base. 

 Petals rounded-oval to suborbicular ; bract small, inserted above the 



middle of the scape. 5^. P. californica. 



Petals elliptic to oval ; bract rather ample, inserted at or below the 

 middle of the scape. 

 Staminodia 7-15 in each fascicle; basal leaf-blades cordate or rounded 

 at the base. 

 Petals nearly twi^e as long as the sepals ; hypanthium incon- 

 spicuous ; staminodia usually 9-15. 6. P. palustris. 

 Petals only slightly exceeding the sepals ; hypanthium con- 

 spicuous, obconic, fully half as long as the sepals and nearly 

 as broad as high ; staminodia 7-9. 7. P. fnontanensis . 

 Staminodia 5-7 in each fascicle ; basal leaf -blades acute at the base. 8. P. parvijlora. 

 Petals 3-veined, thin, scarcely equaling the sepals; capsule twice as long 

 as the sepals ; bract none or near the base. 9. P. Kotzehuei. 

 Staminodia 3-5 in each fascicle, nearly free, not forming an obovate scale 

 below ; petals entire. 

 Petals sessile ; basal leaf -blades from orbicular or cordate to elliptic. 

 Staminodia much longer than the stamens. 



Petals elliptic to oval^ 5-7-veined : anthers acute. 10. P. grandifolia. 



Petals rounded oval, irregularly many-veined ; anthers obtuse. 11. P.floridana. 



Staminodia not longer than the stamens. 12. P. caroliniana. 



Petals clawed ; basal leaf-blades reniform ; staminodia not exceeding the 

 stamens. 13. P. asarifolia. 



Voi^UME 22, Part 1, 1905] 77 



