Risky Lilies

Death Camas amid the grasses

Primarily due to their inability to move around to escape danger, plants have developed an array of weapons to defend themselves against predators.  Some defenses are physical, such as thorns or stinging hairs, and others are chemical, mostly in the form of poisons or toxins.  After these harmful chemicals are produced by the plants, they are locked away in parts of the its cells called vacuoles, spaces within the cell that are enclosed by a membrane, protecting the plant from contamination.

The most common way that people or animals come in contact with poisonous plants is to accidentally eat them.  While we don’t normally eat the plants in our landscapes, widely planted ornamentals that are non-native and toxic include oleander, daffodil, elephant ear, iris, wisteria, and azalea.  Native plants can be toxic too, and there are two species in the Lily Family blooming this time of year that are fairly common but known to be toxic. They are Death Camas (Zigadenus nuttallii) and Crow Poison (Nothoscordum bivalve), and just their common names give them away!

The clustered flower head of Death Camas

Death Camas, also known as Nuttall’s Death Camas, Poison Camas, Poison-onion, and Poison Sego, is a perennial flower growing 1 to 2 feet tall, with narrow basal leaves up to 15 inches long.  A stout stem arises from a large, black-coated bulb, with a round-topped cluster of up to 60 cream-colored, 0.5 inch blooms growing around the top.  It blooms from February to April and is found in open prairies, woodland edges, and rocky hillsides in central and northeast Texas.  

Death Camas is a good early nectar source for butterflies

All parts of this plant are poisonous, even when dry.  While unpalatable, livestock has been known to eat it, but typically only in early spring when not much else is available.  While not in the same genus as edible Camas (Camassia sp.), humans have been poisoned, mistaking the bulbs for wild onion. 

Crow Poison is often mistaken for wild onion

Crow Poison, also known as Crowpoison and False Garlic, is one of the first flowers to appear in early spring throughout most of Texas.  Looking much like wild onion, it grows from a bulb but has fewer, larger white flowers about 0.5 inch across in loose clusters atop 8 to 16 inch stalks, and lacks the characteristic onion odor when crushed. Its basal leaves are narrow and 4 to 15 inches long, and it is found in lawns, open slopes, prairies, disturbed sites, open woodlands, and roadsides, where it often forms large colonies.  

Crow Poison blooms in loose clusters

When dug up, it will have a cluster of attached bulbs underground.  While this plant is minimally toxic to humans, it gets its common name from grain farmers’ past practice of crushing its bulbs and mixing them with a handful of grain to be left out for crows to eat.  In turn, the crows would get sick, with some dying, signaling the surviving crows to move on to other sources of grain. 

Now those are some pretty risky lilies!

Tree Serpents

Rough Greensnakes are excellent climbers.

One of the most beautiful and harmless snakes in Texas is the aptly named Rough Greensnake (Opheodrys aestivus).  Its genus is derived from the Greek ophios meaning ‘serpent’, and drys meaning ‘tree.’  It has a 22 to 32 inch long and slender bright green body, which fades to yellow or yellow-green on the sides near its abdomen.  Common to the eastern two-thirds of Texas, this snake is also colloquially called grass snake, green tree snake, and vine snake, but it gets its most recognized common name from its dorsal or topside scales, which are rough or ‘keeled’, having a ridge down the center rather than being smooth.

Primarily arboreal, the Rough Greensnake is found in open deciduous forest, pastures, and suburban gardens, most frequently those adjoining a watercourse such as a creek, stream, lake, river, or upland ravine.  It climbs into bushes, shrubs, and trees, favoring those with horizontal rather than vertical growth, both for protection and to forage for food.   It hunts crickets, grasshoppers, and spiders, as well as caterpillars of butterflies and moths.  Rough Greensnakes are diurnal, and they sleep at night coiled up on branches of vegetation.  Active most months of the year except for December through February, they take refuge in the cooler months hiding under rocks, logs, or debris.

Rough Greensnakes are also called 'grass snakes', due to their
bright green bodies that fade to yellow on their sides and abdomen.

One of the most curious facts about this snake, and others in this genus, is that they turn blue shortly after death.  Yellow pigment combines with blue pigment to give the snake its vibrant green color during life, but when it dies, the yellow pigment breaks down quickly and only the blue pigment remains.  Rough Greensnakes may be confused with Smooth Greensnakes (O. vernalis), but the latter, while similar in color, is shorter in length, has smooth dorsal scales, and occurs only as a relict population along the Gulf Coast of Texas.

While Rough Greensnakes become active as early as March, they mate in June and July, with females laying clutches of eggs in the second half of summer, typically in a depression under a flat rock.  Incubation is short – only 4 to 24 days – since embryonic development begins while the eggs are still in the female’s body.  These snakes can be most active in August or September, when the young emerge and are foraging for food, often in grassy lawns.  Be alert for these snakes when mowing grass at this time of year, as they are beautiful, harmless, and beneficial creatures!