The Variations of Sagittaria subulata 



Robert T. Clausen 



The phase of Sagittaria subulata which occurs in shallow pools 

 in west-central Florida and elsewhere on the southern coastal plain 

 is considerably different from the plant of tidal shores in the north- 

 eastern states. The southern plant is larger and often more robust ; 

 it also tends to have ovate-elliptical foliage blades. I have distributed 

 specimens of this from Citrus County, Florida, under a manuscript 

 name which now requires validation. 



As here interpreted, 5". subulata comprises two subspecies 

 which are markedly ecologically correlated and somewhat geo- 

 graphically distinguished. These differ as follows : 



A. Plants small, 3-15 cm. high, or very slender and elongate; phyllodia 

 not blade-bearing, in the typical condition usually less than 10 

 cm. long and always less than 0.3 cm. wide ; beaks of achenes 

 0.3-0.4 mm. long S. subulata ssp. typica 



AA. Plants large, often robust, 10-45 cm. or more high ; phyllodia 

 10-40 cm. or more long and 0.3-1 cm. wide, either without or 



with ovate-elliptical blades ; beaks of achenes 0.2 mm. long 



5^. subulata ssp. lorata 



S. subulata (L.) Buchenau, ssp. typica (Alisma subulata L., 

 Sp. PI. 1: 343. 1753). This is a plant of tidal mud flats, ranging 

 from Massachusetts south to northern Florida. The var. gracillima 

 (Wats.) J. G. Smith seems to be a slender, elongate phase which 

 occasionally occurs in deep water. 



.y. subulata ssp. lorata (Chapm.) comb. nov. (S. natans Michx., 

 Fl. Bor. Am. 2: 190. 1803 (not Pall, 1776) ; S. natans var. lorata 

 Chapman, Fl. So. U. S. 449. 1860; 6". subulata natans (Michx.) 

 J. G. Smith, N. Am. Sp. Sagittaria and Lophotocarpus, 18. 1894; 

 5. lorata (Chapm.) Small, No. Am. Fl. 17:52. 1909; 6^. stagno- 

 rum Small, Man. Southeast. Fl. 24. 1933 ; S. subulata var. lorata 

 (Chapm.) Fernald, Rhodora 42:409. 1940). 



According to Small (1933), the achenes of the plants which he 

 designated as S. stagnoruni and 5". lorata are larger, while the 

 beaks of the achenes are shorter than in 6". subulata. In the achenes 

 measured by me, the beaks were 0.2 mm. long in ssp. lorata and 

 0.3-0.4 mm. in ssp. typica. In considering S. subulata, S. natans 

 and 5. lorata to be conspecific, the opinion expressed here concurs 



161 



