Family Sarcobataceae

Sarcobataceae Behnke

Habit and leaf form. Spiny shrubs. Plants succulent (and spiny). Leptocaul. Halophytic. Leaves alternate; spiral; terete; fleshy; sessile; simple. Lamina entire; linear. Leaves exstipulate.

Stem anatomy. Secondary thickening anomalous. ‘Included’ phloem present. Xylem with libriform fibres. Wood parenchyma paratracheal. Sieve-tube plastids P-type; type III (but containing a central protein crystal, unlike those typifying Chenopodiaceae).

Reproductive type, pollination. Fertile flowers functionally male and functionally female. Plants monoecious (according to Behnke (1997)), or monoecious and dioecious (Yamplolsky and Yampolsky (1922)). Female flowers without staminodes. Gynoecium of male flowers absent.

Inflorescence, floral, fruit and seed morphology. Flowers solitary (female), or aggregated in ‘inflorescences’ (male); when solitary and female, axillary; when aggregated and male, in catkins; ebracteolate.

Perianth sepaline (represented by the perigonium of female flowers), or vestigial to absent (male flowers); of female flowers, fleshy; accrescent. Calyx 2 (in female flowers only, represented by the bilobed perigonium); gamosepalous; blunt-lobed; campanulate; fleshy; persistent; accrescent (coming to enclose the fruit, and winged).

Androecium 1–4. Androecial members free of one another. Stamens 1–4; shortly filantherous. Anthers dehiscing via longitudinal slits; latrorse; tetrasporangiate (‘4-locular’, according to Behnke). Pollen grains aperturate; foraminate (with raised pore margins).

Gynoecium 2 carpelled. The pistil 1 celled. Gynoecium syncarpous; synstylovarious; partly inferior (the perianth adnate). Ovary 1 locular. Gynoecium non-stylate. Styles 1; apical. Stigmas 2; papillate. Placentation basal. Ovules in the single cavity 1.

Fruit enclosed in the fleshy perianth. Seeds non-endospermic. Cotyledons 2. Embryo chlorophyllous; coiled (flat-spiralled).

Geography, cytology. Holarctic. Temperate. Halophytic, in the North American Great Basin and southwestern deserts.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Caryophylliflorae; Caryophyllales. Cronquist’s Subclass Caryophyllidae; Caryophyllales. APG 3 core angiosperms; core eudicot; Superorder Caryophyllanae; Order Caryophyllales.

Species 1. Genera 1; Sarcobatus.

The oddity of Sarcobatus among Chenopodiaceae has long been acknowledged, e.g. by Bentham and Hooker (1880), who presented it as a monogeneric tribe. Behnke (1997) proposed family rank, because sieve-element plastid details support chloroplast DNA sequencing studies in placing it nearer Phytolaccaceae than Chenopodiaceae. He presents an extended exposition on ‘taxonomic history’ (including vernacular names, ethnobiology, etc.), but no organized comparative descriptive data — merely a short Latin diagnosis of the new family. Neither the latter nor the more detailed description attempted here effectively separate it morphologically from Chenopodiaceae.