ADICEA 7 



of that state. In adding to the species 4 new relatives from the 

 northern and central United States, I have found it convenient 

 to divide them in one black-seeded and one green-seeded group 

 and arrange them under the following key: 

 A. Achaenia nigra vel subnigra. 



a. Planta 4-8 cm. longa, per partem dimidiam 

 superiorem foliosa, simplex, achaenia 1.5 mm. 



longa and 1.5 mm. lata i. A. fontana. 



a. Planta 10-30 cm. longa, prope basin sursum 



ramosa, achaenia 2 mm. longa, 1.5 mm. lata.. .2. A. opaca. 

 A. Achaenia viridia. 



a. Planta 15-25 cm. longa, simplex, per partem 

 dimidiam superiorem foliosa, achaenia 1.5 



mm. longa, i % "^ni- lata 3. A. Nieuwlandii 



a. Planta 30-60 cm. longa, prope basin sursum ramosa. 



b. Achaenia i mm. longa, /4-/i mm. lata. . . .4. A. Deamii. 

 b. Achaenia 1.5 mm. longa, i. mm. lata. .5. A. pumila (L) Raf 



A. Achenes black or blackish. 



a. Plant 4-8 cm. long, leafy above the middle 



simple, seeds 1.5 mm. long and 1.5 mm. wide. . i. A. fontana. 

 a. Plant 10-30 cm. long, branching from near 



the base, seeds 2 mm. long, 1.5 mm. wide. . . .2. A. opaca 

 A. Achenes green. 



a. Plant 15-25 cm. long, simple, leafy above the 



middle, seeds 1.5 mm. long, 1% mm. wide . .3. A. Nieuwlandii 

 a. Plant 30-60 cm. long, branching from near 

 the base, 

 b. Achenes i mm. long, K~M mm. wide. . . .4. A. Deamii. 

 b. Achenes 1.5 mm. long, i mm. wide. .5. A. pumila (L.) Raf. 



I. Adicea fontana sp. nov. 

 Caulis annuus, gracilis, simplex, teres, pellucidus, paene 

 erectus, appresse pilosus vel glabratus, 4-8 cm. altus, recens 

 apice tantum foliosus, postea autem foliis geminis in caule 

 medio vel iuxta eum positis. Quae folia infima parvo sunt, 

 3-5 mm. diametro, orbicularia, vel basi rotundata vel paene 

 truncata suborbicularia, margine fere integro et petiolis longi- 

 tudini foliorum aequalibus. Folia omnia opposita et petiolata 

 geminaque 2-4 in summo caule conferta, quae ampliora, 7-20 

 mm. longa, viva etiam membranacea, ovata, magis minusve 



