Psorodendron Rydb., N. Amer. Fl.

Psorodendron Rydb., N. Amer. Fl. View in CoL 24(1): 41 (1919).

Type: Dalea johnsonii S. Wats.

Stoloniferous herbs, shrubs or trees to 7(-10) m tall. Branches often spinescent; stems glabrous or sparsely strigulose or vestured with ascending, appressed indument. Leaves pinnate or simple, caducous or persistent at anthesis. Inflorescences loosely racemose or spicate, the axis becoming spiniform during or after blooming. Flowers subtended by a deciduous bract and two small subulate bracteoles at the base of the short pedicels. Petals glabrous, with or without glands. Apex of the connective with or without a gland. Ovules 2-7 per ovary. Pods to 1 cm long, inserted to exserted.

Psorodendron View in CoL , as reinstated here, comprises five species widespread in desert basins of Arizona, Baja California, California, Nevada, and Utah ( United States). Full synonymy of all five species (based on Barneby, 1977) is given below; names marked with asterisk correspond to Psorodendron View in CoL binomials treated under the synonymy of Psorothamnus spp. by Barneby (1977).

Psorodendron arborescens (Torr.) Rydb. View in CoL = Dalea amoena S. Watson View in CoL = Dalea arborescens Torr. ex A.Gray View in CoL = Dalea californica (S.Watson) Vail View in CoL = Dalea fremontii var. minutifolia (Parish) L.Benson View in CoL = Dalea fremontii var. pubescens (Parish) L.Benson View in CoL = Dalea fremontii var. saundersii (Parish) Munz View in CoL = Dalea fremontii var. simplifolia (Parish) L.Benson View in CoL = Dalea saundersii Parish View in CoL = Parosela amoena (S. Watson) Vail View in CoL = Parosela arborescens (Torr.) A.Hell. View in CoL = Parosela californica (S.Watson) Vail View in CoL = Parosela fremontii var. wheleri (Vail) B.L. Robins. ex MacBr. = Parosela fremontii var. saundersii (Parish) MacBride View in CoL = Parosela johnsoni var. minutifolia Parish View in CoL = Parosela johnsoni var. saundersii (Parish) Parish View in CoL = Parosela neglecta Parish View in CoL = Parosela saundersii (Parish) Abrams View in CoL = Parosela wheeleri Vail View in CoL = Psorodendron amoenum (S.Watson) Rydb. View in CoL *; Psorodendron californicum (S.Watson) Rydb. View in CoL * = Psorodendron pubescens (Parish) Rydb. View in CoL * = Psorodendron saundersii (Parish) Rydb. View in CoL * = Psorodendron wheeleri (Vail) Rydb. View in CoL * = Psorothamnus arborescens (A.Gray) Barneby View in CoL = Psorothamnus arborescens (A.Gray) Barneby var. minutifolius (Parish) Barneby View in CoL = Psorothamnus arborescens (A.Gray) Barneby var. pubescens (Parish) Barneby. View in CoL

Psorodendron fremontii (Torr.) Rydb. = Dalea fremontii Torr. ex A.Gray = Dalea johnsonii S.Watson = Parosela fremontii (Torr.) Vail = Parosela johnsonii (S.Watson) Vail = Psorodendron johnsonii (S.Watson) Rydb. = Psorothamnus fremontii (Torr.) Barneby.

Psorodendron kingii (S. Watson) Rydb. = Dalea kingii S.Wats. = Parosella kingii A. Heller = Psorothamnus kingii (S.Watson) Barneby.

Psorodendron schottii (Torr.) Rydb. = Dalea schottii Torr. = Parosela schottii (Torr.) A.Hell. = Parosela schottii var. puberula Parish = Psorodendron puberulum (Parish) Rydb. * = Psorothamnus schottii (Torr.) Barneby.

Psorodendron spinosum (A.Gray) Rydb. View in CoL = Dalea spinosa A.Gray = Asagraea spinosa (A.Gray) Baillon = Parosella spinosa (A.Gray) A. Hell. = Psorothamnus spinosus (A.Gray) Barneby.

4. Dalea is paraphyletic with respect to Marina , as D. filiciformis results sister to Marina . This result was obtained in all the partitioned and the combined analyses, including that based on the ITS- trnK/matK dataset with a significantly increased sampling within the species-rich Dalea . The bootstrap values that support this particular result ranged from 95 % in the ITS-based analysis (Suppl. Fig. 1 View Figure 1 ) to 100 % in the combined ITS + matK/trnK analysis ( Fig. 2 View Figure 2 ). Barneby (1977: 149) already stated that D. filiciformis “has no really close relative in Dalea and its affinities are difficult to estimate,” and pointed out its pod morphology resembles that found in Marina species. Thus, the following formal transfer is required: