3. Froelichia Moench (cottonweed, snake-cotton)
(perennial herbs elsewhere), but with the taproot sometimes appearing somewhat
woody. Aerial stems erect or strongly ascending, somewhat angled, densely
pubescent with unbranched, usually woolly hairs, especially the nodes often
appearing cobwebby, the hairs becoming shorter near the tip, occasionally also
somewhat sticky. Leaves opposite, positioned mostly below the stem midpoint,
sessile or nearly so. Leaf blades 5–14 cm long, somewhat thickened or
leathery, linear to narrowly oblong-lanceolate or narrowly oblanceolate,
narrowed or tapered at the base, narrowed or tapered to a sharply or bluntly
pointed tip, the margins entire, the upper surface densely pubescent with silky
or woolly hairs but frequently becoming nearly glabrous at maturity, the
undersurface densely persistently pubescent with woolly hairs. Inflorescences
terminal, narrow panicles with pairs of dense spikes ascending from the nodes
of the main axis, these sometimes reduced to short, dense clusters and the
inflorescence then appearing as an interrupted spike, the lateral branches
often terminating in simple spikes. Bracts similar in texture but much shorter
than the sepals, broadly ovate, papery or scalelike, glabrous. Flowers perfect.
Sepals 5, fused most of their length into a persistent, conical to
flask-shaped, papery tube, this becoming somewhat hardened and developing
winglike longitudinal ridges or rows of spines and also basal tubercles after
flowering, white to yellowish white, densely pubescent with woolly hairs, the
lobes 1–2 mm long, oblong to lanceolate, bluntly to sharply pointed, greenish
white, sometimes pinkish-tinged, more or less glabrous. Stamens 5, the
filaments fused nearly their entire length, persistent, the anthers appearing
sessile in the sinuses between 5 short, strap-shaped lobes. Ovary ovoid. Ovule
1. Style well developed, persistent, the stigma 1, capitate. Fruits shorter
than and hidden within the persistent calyx and anther tubes, with membranous
walls, ovoid, glabrous, indehiscent, 1-seeded. Seeds somewhat flattened,
circular or nearly so in outline, the surface shiny. Twelve to 20 species, U.S.
and adjacent Canada to South America, Caribbean Islands.
To observe the
crests and tubercles on the fruiting calyx, it is necessary to first remove the
thick woolly covering of hair.