a	Leaves reduced to scales, or if developed, then fleshy or semisucculent Namibia and Northern Cape
	b	Leaves well developed, not fleshy All regions of southern Africa

	a	Leaves alternate or occasionally opposite, often reduced to scales, or if developed then fleshy Branchlets twiggy, very shortly woolly	Calicorema
	b	Leaves opposite, scale-like Opposite branches articulate Branchlets glabrous	Arthraerua

	a	Leaves alternate or fasciculate or sometimes opposite
	b	Leaves opposite

	a	Modified sterile flowers present alongside fertile flowers, formed of wings, scales, spines, hairs or bristles Tepals pilose or floccose Stigma with a tuft of hairs
	b	No modified sterile flowers present alongside fertile flowers Tepals pilose or glabrous Stigma without a tuft of hairs

	a	Sterile flowers of strap-shaped processes furnished with long unicellular hairs, forming a silky-haired ball in fruit Tuft of hairs of stigma not purplish	Sericorema
	b	Sterile flowers formed of long hairs and pilose spines Tuft of hairs of stigma purplish	Marcelliopsis

	a	Ovaries with more than one ovule
	b	Ovaries uniovulate

	a	Stamens fused for at least half their length in a tube, either with large bifid intermediate pseudostaminodes, or with a sterile tooth on each side of antheriferous tooth or each filament widely expanded	Hermbstaedtia
	b	Stamens not fused, pseudostaminodes 0 or small, filaments never widely expanded nor with a sterile tooth on each side of anther

	a	Inflorescences white-woolly Tepals dorsally densely lanate	Aerva
	b	Inflorescences not white-woolly Tepals glabrous or pilose about the base only	Celosia

	a	Flowers unisexual, male flowers situated towards apex of inflorescences or scattered among females, or plants dioecious Tepals glabrous Pseudostaminodes 0	Amaranthus
	b	Flowers bisexual, or if unisexual tepals ± hairy and pseudostaminodes present

	a	Leaves narrowly to broadly elliptic, elliptic-oblong or ovate Flowers minute, ± 1.25 mm long Stamens 1 or 2	Nothosaerva
	b	Leaves narrow, linear Flowers larger Stamens 5	Sericocoma

	a	Bracteoles with a projecting dorsal keel along at least upper part of midrib	*Gomphrena
	b	Bracteoles without dorsal keel along midrib

	a	Modified sterile flowers present, consisting of hairs, spines, bristles or scales, frequently on one side of sterile flower, sometimes concealed within bracteoles in flowering stage
	b	Modified sterile flowers 0, all flowers fertile

	a	Stamens without intermediate pseudostaminodes
	b	Stamens with intermediate pseudostaminodes

	a	Modified sterile flowers consisting of numerous uncinately hooked spines	Pupalia
	b	Modified sterile flowers without hooked spines

	a	Inflorescence capitate Leaves narrowly or widely elliptic to lanceolate or ovate Densely canescent	Leucosphaera
	b	Inflorescence spicate Leaves linear-acicular to narrowly oblong, glabrous	Centema

	a	Leaves narrowly linear Ovary asymmetrically horned at apex	Kyphocarpa
	b	Leaves broadly linear or narrowly oblong, opposite sterile flowers of single rigid spines Ovary without an apical horn

	a	Sterile flowers of long plumose-pilose processes	Nelsia
	b	Sterile flowers of spines or bracteoliform processes, never plumose-pilose	Cyathula

	a	Anthers 1-thecous Plants mainly prostrate or decumbent and diffusely branched
	b	Anthers 2-thecous Plants mainly erect

	a	Stamens perigynous Tepals densely woolly-lanuginose, 1-nerved, fused to ± halfway	*Guilleminea
	b	Stamens hypogynous Tepals glabrous and 1-nerved or barbellate-pilose and 3-nerved, free

	a	Stigma capitate Flower clusters sessile in axils of leaves	*Alternanthera
	b	Stigmas 2 or 3 Flowers in dense spikes or terminal, sessile heads	*Gomphrena

	a	Stamens 1 or 2 Flowers minute, ± 1.25 mm long Leaves, branches and flower clusters varying from alternate to opposite	Nothosaerva
	b	Stamens 4 or 5 Flowers minute to larger Leaves and branches constantly alternate or opposite, or else flowers 4.5-6.0 mm long

	a	Pseudostaminodes absent between filaments	Psilotrichum
	b	Pseudostaminodes present between filaments

	a	Robust aquatic or marsh perennial Upper tepal slightly longer than remainder with a sharper and often slightly recurved apex	Centrostachys
	b	Plant not truly aquatic or paludal Upper tepal not thus differentiated

	a	Tepals pilose throughout	Pandiaka
	b	Tepals glabrous, or floccose below the middle only

	a	Fruiting perianth strongly deflexed, closely appressed to inflorescence axis Bracteoles spinous aristate, arista longer than basal wings, or inflorescences fasciculate and formed of several spikes of diverse lengths	Achyranthes
	b	Fruiting perianth not or less deflexed, not closely appressed to inflorescence axis Bracteoles frequently with midrib excurrent, but not long and spinose Inflorescence a solitary spike	Achyropsis