1955] 



REVISION OF THE GENUS SAGITTARIA 



201 



most closely related to S. montevidensis subsp. calycina, from which it has ap- 

 parently evolved. The two plants grow side by side without any reported hybridi- 

 zation, and while they do resemble each other, they are certainly distinct, the 

 most important differences being the reduced or obsolete beak of the mature achene 

 in sanfordii and the small, relaxed sepals of the pistillate flower. None of the 

 specimens examined shows any signs of functional stamens in the pistillate 

 flowers, but presumably that condition does exist. S. sanfordii and S. subulata are 

 the only members of the subgenus perennating by runners and corms, a condition 

 common throughout the Sagittariae and undoubtedly correlated with a more northern 

 distribution. 



This species until recently was very poorly represented in herbaria and most 

 of the specimens that were seen came from the locality of the type collection. 

 Knowledge of the full range of the plant and a better understanding of its char- 

 acteristics are due in large measure to the thorough field collections made by 

 Mason et al. 



6. Sagittaria intermedia Micheli in DC„ Monogr. Phan. 3: 80. 1881. 

 Sagittaria acutifolia Griseb. Cat. PI. Cuba 218. 1866. 



Perennial with short rhizome. Emersed leaves typically sagittate, the blades 

 lanceolate to ovate, 1.5-12 x 0.4- 13 cm, the lobes linear to deltoid, 3.5-11 x 0.3-7 

 cm, occasionally absent, the submerged leaves reduced to lanceolate phyllodia 

 5-10 x 0.7- 1.2 cm, the occasional floating leaves cordate; petioles 9-75 cm long. 

 Scape with 2-9 whorls of flowers, simple or branching from the lowest whorl. 

 Bracts connate, 0.2-0.6 cm long, often reduced or obsolete. Pistillate flowers 

 with thickened, recurved pedicels 0.6-2.0 cm long; sepals ovate, 0.4-0.8 cm long, 

 loosely appressed to the mature receptacle or somewhat spreading; petals white, 

 about twice as long as the sepals; ring of functional stamens occasionally present. 

 Staminate flowers with short, filiform pedicels to 1.0 cm long; stamens 12-21, 

 the glabrous to slightly pubescent filaments 0.9-1.3 mm long, somewhat dilated 

 at the base, the oblong anthers about 1 mm long. Mature pistillate heads 1.0-1.5 

 cm in diameter; achenes obovate, 1.7-2.2 x 0.9-1.4 mm, the wings 0.25-0.4 mm 

 wide, slightly eroded dorsally, the faces tuberculate or tuberculate-winged, a 

 short resin duct occasionally present, the minute beak 0.1-0.4 mm long, laterally 

 inserted. (FIG. 6.) 



Type collection: Wright 3199, Cuba (lectotype K, isolectotypes GH, MO, NY, 

 US). Micheli based his name on 5. acutifolia Griseb., who cited Wright 3199 and 

 Wright 3201. Micheli, too, cited these specimens in Kew among others, without 

 designating any holotype. Specimens of Wright 3199 in the American herbaria all 

 have mature achenes and uniformly typify the species. None of these specimens 

 were seen by Micheli, however, so the plant at Kew which he did see must be 

 designated as the lectotype. 



Distribution: Caribbean coast of Colombia and the larger West Indian Islands. 

 A common species of widely diverse, aquatic habitats, including bogs, ditches, 

 and salt ponds. Collections examined from Colombia in South America and from 

 Cuba, Dominican Republic, Haiti, Jamaica, and Puerto Rico in the West Indies. 

 (FIG. 6.) 



Certain collections of Sagittaria montevidensis from South America with 

 achenes that have their faces slightly tuberculate have occasionally been identi- 

 fied as S, intermedia. Close comparison of the two species, however, shows 

 sufficient basis for maintaining them as separate and distinct. The two species 

 are undoubtedly very closely related and superficially resemble each other in the 



