KEY TO THE SPECIES OF SESUVIUM

(INCL. CYPSELEA)

1. Margin of the lateral flaps of the petiole fimbriate (Fig. 3B)..................................................................... 2

1. Margin of the lateral flaps of the petiole entire (Fig. 3A)....................................................................... 3

2. Flowers white, 3 stamens............................................................................. Sesuoium humifusum

2. Flowers red, 5 stamens............................................................................... Sesuoium rubriflorum

3. Shoots smooth: usually without bulging bladder cells (Fig. 3C).............................................................. 4

3. Shoots densely covered with bulging bladder cells (Fig. 3C)................................................................ 9

4. Stems rooting at nodes.......................................................................................... 5

4. Stems not rooting at nodes....................................................................................... 6

5. Flowers pink or white; many stamens; worldwide distribution..................................... Sesuoium portulacastrum

5. Flowers (greenish-) white; 3 stamens; Paraguay..................................................... Sesuoium mezianum

6. Closed flowers ± ovoid (Fig. 3F); northern America or Caribbean..................................................... 7

6. Closed flowers turbinate (Fig. 3E); Africa........................................................................ 8

7. Seeds smooth, up to ∼ 1 mm long; capsule ± ovoid, not longer than the perigone...................... Sesuoium maritimum

7. Seeds wrinkled, up to 1.5 mm long; capsule tapered, slightly longer than the perigone................ Sesuoium trianthemoides

8. Seed coat ± smooth (Fig. 3I); leaves broadly elliptic; dried shoots often slightly olive-colored.............. Sesuoium sesuoioides

8. Seed coat clearly structured (Figs. 3G and H); leaves elliptic to narrowly elliptic; dried shoots can be reddish............................................................... Sesuoium hydaspicum

9. Several pairs of bracts (each bract ∼ 5 mm long)....................................................................... 10

9. One pair of bracts (each bract ∼ 1 mm long).......................................................................... 11

10. Leaves long and narrow, 20–70 mm long......................................................... Sesuoium crithmoides

10. Leaves broad-elliptic, 10–20(–30) mm long................................................ Sesuoium mesembryanthemoides

11. Pseudostipules of petiole with bladder cells....................................................... Sesuoium edmonstonei

11. Pseudostipules of petiole without bladder cells................................................................... 12

12. Closed flower turbinate (Fig. 3E), leaves narrowly to broadly elliptic.............................................. 13

12. Closed flower ovoid (Fig. 3F), leaves obovate to oblanceolate, sometimes linear....................... Sesuoium oerrucosum

13. Ovary with 2 or 3 carpels; leaves narrowly elliptic, semi-terete in cross section, usually densely covered with globose to slightly ovoid or fusiform bladder cells................... Sesuoium congense

13. Ovary invariably with 2 carpels; leaves broadly elliptic, often folded along midvein, ± flat, loosely to densely covered with globose bladder cells.................................. Sesuoium sesuoioides