- Spikelet of Oat, A.
- Spikelet of Wild Oat, sativa, with two fertile florets, A.
They are called " huitzilin " (spikelet) by the 'Aztecs, and " colibri," " chupaflor " and " chupa-miel " (floweror honey-sucker), and " pajaromosca " (fly-bird) by the Spanish-speaking Mexicans.
1, single spikelet; 2, single flower with awned plume and palea; 3, pistil; 4, grain.
Each spikelet contains a solitary flower with two outer small barren glumes, above which is a large tough, compressed, often awned, flowering glume, which partly encloses the somewhat similar pale.
The cultivated varieties are extremely numerous, some kinds being adapted for marshy land, others for growth on the hill A, spikelet (enlarged) B, bearded variety sides.
The cultivators p g) y' make two principal C, spikelet of B (enlarged).
3 is a single spikelet of the same, containing two florets, with the three stamens of one only protruded.
5 is a spikelet of the female inflorescence, consisting of two outer glumes, the lower one ciliated, which enclose two florets - one (a) barren (sometimes fertile), consisting of a flowering glume and pale only, and the other (b) fertile, containing the pistil with elongated style.
I, Spikelet of same; 2, flower.
- Two-flowered spikelet spikelet of Agrostis.
- Spikelet of Briza.
- Spikelet of Triticum.
The pale is now generally considered to represent the single bracteole, characteristic of Monocotyledons, the binerved structure being the result of the pressure of the axis of the spikelet during the development of the pale, as in Iris and others.
- Spikelet of Anthoxanthum (enlarged) without the two lower barren glumes, showing the two upper awned barren glumes (g) and the flower.
9), Coleanthus, Nardus) the spikelet consists of nothing more, but usually (even in uniflorous spikelets) other glumes are present.
Of these the two placed distichously opposite each other at the base of the spikelet never bear any flower in thei axils, and are called the empty or barren glumes (figs.
They are commonly firm and strong, often enclose the spikelet, and are rarely provided with long points or imperfect awns.
The axis of the spikelet is frequently jointed and breaks up into articulations above each flower.
In Cynosurus (Dog's tail) -- C the pectinate involucre which conceals the spikelet is a barren or abortive spikelet.
It is closed except at the apex, and contains the female spikelet, the stalks of the male inflorescence and the long styles emerging through the small apical orifice.
- Spikelet of Spikelet of LeerSetaria, with an abortive sia.
- Spikelet of Stipa pennata.
- Spikelet of Reed (Phragmites cornmunis) opened out.
- Spikelet of Cenchrus echinatus enclosed in a bristly involucre.
18, and Paniceae), and in these the male flower of a spikelet always blooms later than the hermaphrodite, so that its pollen can only effect cross-fertilization upon other spikelets in the same or another plant.
Various methods of scattering the: grain have been adopted, in which parts of the spikelet or inflorescence are concerned.
Short spikes may fall from the culm as a whole; or the axis of a spike or raceme is jointed so that one spikelet falls with each joint as in many Andropogoneae and Hordeae.
The entire spikelet, or single flowers, are transformed into small-leaved shoots which fall from the axes and readily root in the ground.
Robert Brown suggested two primary divisions - Paniceae and Poaceae, according to the position of the most perfect flower in the spikelet; this is the upper (apparently) terminal one in the first, whilst in the second it occupies the lower position, the more imperfect ones (if any) being above it.
Munro supplemented this by another character easier of verification, and of even greater constancy, in the articulation of the pedicel in the Paniceae immediately below the glumes; whilst in Poaceae this does not occur, but the axis of the spikelet frequently articulates above the pair of empty basal glumes.
In Setaria and allied genera the spikelet is subtended by an involucre of bristles or spines which represent sterile branches of the inflorescence.
Spikelet of Hierochloe.
At the base of each spikelet are two empty boat-shaped glumes or "chaff-scales," one to the right, the other to the left, and then a series of flowers, 2 to 8 in number, closely crowded together; the uppermost are abortive or sterile, - indeed, in some varieties only one or two of the flowers are fertile.
- Spikelet and Flowers of Wheat.
A, Spikelet magnified.
In the common wheats the chaffscales are boat-shaped, ovoid, of the consistence of parchment, and shorter than the spikelet; the seed is usually floury, opaque, white, and easily broken.
The Polish wheat, rarely if ever cultivated in the United Kingdom, has very large lanceolate glumes, longer than the spikelet, and elongated glassy seeds.
- Spikelet of Oat (Avena sativa) laid open, showing the sterile bracts gl, gl, or empty glumes; g, the fertile or floral glume, with a dorsal awn a; p, the pale; fs, an abortive flower.
- Spikelet of Reed (Phragmites communis) opened out.