I once observed a crop of burnet, in which Bromus secalius (Lob Grass) was growing, whose spike stood a considerable height above the crop, and several acres of which a boy or woman might have cut over in a short space of time:  but it was not so:  the grass seeds and burnet were suffered to ripen together, and no means could be devised to separate the two when threshed.  For this reason the burnet seeds never could find a market, and consequently the trouble of saving it, as well as the crop, was lost to the grower.  I mention this as an instance of many that frequently occur.  How many times do we see with crops of winter tares wild oats seeding in them? or Carduus mutans standing so high above those crops that they might be thus extirpated with great ease?

It may be observed, that it is in culture of this nature where annual seeds multiply.  A regular crop of wheat will, by its thickness on the ground, retard their growth by smothering them; but the other gives them every facility, and particularly autumnal-sown crops.

664.  Blue-bottle    —    —    —    Centaurea Cyanus.
665.  White-blite    —    —    —    Chenopodium album.
666.  Charlock       —    —    —    Sinapis arvensis.
667.  Chickweed      —    —    —    Alsine media.
668.  Cockle         —    —    —    Agrostemma Githago.
669.  Cleavers       —    —    —    Galium Aparine.
670.  Corn Marigold  —    —    —    Chrysanthemum segetum.
671.  Corn Crowfoot  —    —    —    Ranunculus arvensis.
672.  Corn Chamomile —    —    —    Matricaria Chamomilla.
673.  Weak-scented do     -    -    ---------- inodora.
674.  Grass, Lob     —    —    —    Bromus secalinus.
675. -----  Bearded Oat  -    -    Acena fatua.
676. -----  Field Foxtail     -    Alopecurus agrestis.
677. -----  Darnel  -    -    -    Lolium temulentum.
678.  Groundsel, common   —    —    Senecio vulgaris.
679.  Wall Barley    —    —    —    Hordeum murinum.
680.  Mallow, common —    —    —    Malva sylvestris.
681.  Mayweed, stinking 	 —    —    Anthemis Cotula.
682.  Melilot        —    —    —    Trifolium officinale.
683.  Mustard, white —    —    —    Sinapis alba.
684. -------, hedge -    -    -    Erysimum Barbarea.
685.  Nettle, Stinging, small  —    Urtica urens.
686. ------, Dead   -    -    -    Lamium albium.
687.  Nipplewort     —    —    —    Lapsana communis.
688.  Orach, wild    —    —    —    Atriplex hastata.
689. -----, spreading 	 -    -    -------- patulata.
690.  Pilewort       —    —    —    Ranunculus ficaria.
691.  Persicaria, spotted-leaved    Polygonum Ficaria.
692. ----------, pale-flowered     --------- pensylvanicum.
693. ----------, climbing     -    --------- Convolvulus.
694.  Pheasant-eye   —    —    —    Adonis autumnalis.
695.  Poppy, common red 	 —    —    Papaver Rhoeas.
696.  Poppy, long rough-headed —    Papaver Argemone.
697.  Radish, wild   —    —    —    Raphanus Raphanistrum.
698.  Shepherd’s Needle   —    —    Scandix Pecten Veneris.
699.  Spearwort      —    —    —    Ranunculus Flammula.